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The Farrell--Tate and Bredon homology for PSL_4(Z) and other arithmetic groups ; Rahm, Alexander ; E-print/Working paper (in press) We provide some new computations of Farrell--Tate and Bredon (co)homology for arithmetic groups. For calculations of Farrell--Tate or Bredon homology, one needs cell complexes where cell stabilizers fix ... [more ▼] We provide some new computations of Farrell--Tate and Bredon (co)homology for arithmetic groups. For calculations of Farrell--Tate or Bredon homology, one needs cell complexes where cell stabilizers fix their cells pointwise. We provide an algorithm computing an efficient subdivision of a complex to achieve this rigidity property. Applying this algorithm to available cell complexes for PSL_4(Z) and PGL_3(Z[i]) provides computations of Farrell--Tate cohomology for small primes as well as the Bredon homology for the classifying spaces of proper actions with coefficients in the complex representation ring. On the other hand, to check correctness of the computer calculations, we describe the Farrell--Tate cohomology in some rank-one cases, using Brown's complex and a number-theoretic description of the conjugacy classification of cyclic subgroups. [less ▲] Detailed reference viewed: 59 (5 UL)Yolanda von Vianden und das Yolanda-Epos Sieburg, Heinz E-print/Working paper (in press) Detailed reference viewed: 31 (2 UL)On the Cohomological Crepant Resolution Conjecture for the complexified Bianchi orbifolds ; Rahm, Alexander E-print/Working paper (in press) We give formulae for the Chen--Ruan orbifold cohomology for the orbifolds given by a Bianchi group acting on complex hyperbolic 3-space. The Bianchi groups are the arithmetic groups PSL_2(A), where A is ... [more ▼] We give formulae for the Chen--Ruan orbifold cohomology for the orbifolds given by a Bianchi group acting on complex hyperbolic 3-space. The Bianchi groups are the arithmetic groups PSL_2(A), where A is the ring of integers in an imaginary quadratic number field. The underlying real orbifolds which help us in our study, given by the action of a Bianchi group on real hyperbolic 3-space (which is a model for its classifying space for proper actions), have applications in physics. We then prove that, for any such orbifold, its Chen-Ruan orbifold cohomology ring is isomorphic to the usual cohomology ring of any crepant resolution of its coarse moduli space. By vanishing of the quantum corrections, we show that this result fits in with Ruan's Cohomological Crepant Resolution Conjecture. [less ▲] Detailed reference viewed: 39 (0 UL)The edge-based strain smoothing method for compressible and nearly incompressible non-linear elasticity for solid mechanics ; ; et al E-print/Working paper (in press) Detailed reference viewed: 372 (33 UL)On Farrell-Tate cohomology of SL_2 over S-integers Rahm, Alexander ; E-print/Working paper (in press) Detailed reference viewed: 23 (1 UL)Genuine Bianchi modular forms of higher level, at varying weight and discriminant Rahm, Alexander ; Tsaknias, Panagiotis E-print/Working paper (in press) Bianchi modular forms are automorphic forms over an imaginary quadratic field, associated to a Bianchi group. Even though modern studies of Bianchi modular forms go back to the mid 1960's, most of the ... [more ▼] Bianchi modular forms are automorphic forms over an imaginary quadratic field, associated to a Bianchi group. Even though modern studies of Bianchi modular forms go back to the mid 1960's, most of the fundamental problems surrounding their theory are still wide open. Only for certain types of Bianchi modular forms, which we will call "generic", it is possible at present to develop dimension formulas: They are (twists of) those forms which arise from elliptic cuspidal modular forms via the Langlands base-change procedure, or arise from a quadratic extension of the imaginary quadratic field via automorphic induction (so-called CM-forms). The remaining, non-"generic" Bianchi modular forms are what we call "genuine", and they are of interest for an extension of the modularity theorem (formerly the Taniyama-Shimura conjecture, crucial in the proof of Femat's Last Theorem) to imaginary quadratic fields. In a preceding paper by Rahm and Sengun, an extreme paucity of "genuine" cuspidal Bianchi modular forms has been reported, but those and other computations and were restricted to level One. In this paper, we are extending the formulas for the "generic" Bianchi modular forms to deeper levels, and we are able to spot the first, rare instances of "genuine" forms at deeper level and heavier weight. [less ▲] Detailed reference viewed: 93 (8 UL)3D Printing: The Next 5 years by Claude Wolf – Into the Future engineered by the Zs Wolf, Claude E-print/Working paper (2017) 3D Printing: The Next 5 years by Claude Wolf – Into the Future engineered by the Zs The future of 3D Printing or Additive Manufacturing [AM] will be driven by the next generation of engineers who are just ... [more ▼] 3D Printing: The Next 5 years by Claude Wolf – Into the Future engineered by the Zs The future of 3D Printing or Additive Manufacturing [AM] will be driven by the next generation of engineers who are just about to qualify, the Z generation (1994-2010). Do we, educators, know this Z generation? Do we know what motivates them? The Z generation is a generation of digital natives interacting with PCs, iPads, smartphones and the internet since birth, a pragmatic and short term orientated generation. Our prejudice brands them as unprepared and unmotivated, with their 10 second attention spans, but in reality, they have already proven they are creative, determined and hardworking as well as team oriented, when they are given the opportunity. They have understood that 3D printing offers them this opportunity. [less ▲] Detailed reference viewed: 35 (3 UL)Scattering theory without injectivity radius assumptions and spectral stability for the Ricci flow ; Thalmaier, Anton E-print/Working paper (2017) We prove a completely new integral criterion for the existence and completeness of the wave operators W_{\pm}(-\Delta_h,-\Delta_g, I_{g,h}) corresponding to the (unique self-adjoint realizations of) the ... [more ▼] We prove a completely new integral criterion for the existence and completeness of the wave operators W_{\pm}(-\Delta_h,-\Delta_g, I_{g,h}) corresponding to the (unique self-adjoint realizations of) the Laplace-Beltrami operators -\Delta_j, j=g,h, that are induced by two quasi-isometric complete Riemannian metrics g and h on an open manifold M. In particular, this result provides a criterion for the absolutely continuous spectra of -\Delta_g and -\Delta_h to coincide. Our proof relies on estimates that are obtained using a probabilistic Bismut type formula for the gradient of a heat semigroup. Unlike all previous results, our integral criterion only requires some lower control on the Ricci curvatures and some upper control on the heat kernels, but no control at all on the injectivity radii. As a consequence, we obtain a stability result for the absolutely continuous spectrum under a Ricci flow. [less ▲] Detailed reference viewed: 17 (2 UL)Tommaso Padoa-Schioppa [biography] Chiocchetti, Paolo E-print/Working paper (2017) Tommaso Padoa-Schioppa (1940-2010) was an Italian banker, economist, and politician. He was one of the "architects of the euro" and helped to push forward the financial, monetary, and economic integration ... [more ▼] Tommaso Padoa-Schioppa (1940-2010) was an Italian banker, economist, and politician. He was one of the "architects of the euro" and helped to push forward the financial, monetary, and economic integration of Europe. [less ▲] Detailed reference viewed: 9 (1 UL)Dynamics of Income Rank Volatility: Evidence from Germany and the US Chauvel, Louis ; Hartung, Anne ; E-print/Working paper (2017) This paper presents a methodology for comparing income rank volatility profiles over time and across distributions. While most of the existing measures are affected by changes in marginal distributions ... [more ▼] This paper presents a methodology for comparing income rank volatility profiles over time and across distributions. While most of the existing measures are affected by changes in marginal distributions, this paper proposes a framework that is based on individuals’ relative positions in the distribution, and is neutral in relation to structural changes that occur in the economy. Applying this approach to investigate rank volatility in Germany and the US over three decades, we show that while poorer individuals within both countries are the most volatile, the volatility trend for the middle class in each of these countries differs. [less ▲] Detailed reference viewed: 23 (4 UL)Isogeometric analysis of thin Reissner-Mindlin plates and shells: Locking phenomena and generalized local B-bar method Hu, Qingyuan ; ; et al E-print/Working paper (2017) We propose a generalized local $\bar{B}$ framework, addressing locking in degenerated Reissner-Mindlin plate and shell formulations in the context of isogeometric analysis. Parasitic strain components are ... [more ▼] We propose a generalized local $\bar{B}$ framework, addressing locking in degenerated Reissner-Mindlin plate and shell formulations in the context of isogeometric analysis. Parasitic strain components are projected onto the physical space locally, i.e. at the element level, using a least-squares approach. The formulation is general and allows the flexible utilization of basis functions of different order as the projection bases. The present formulation is much cheaper computationally than the global $\bar{B}$ method. Through numerical examples, we show the consistency of the scheme, although the method is not Hu-Washizu variationally consistent. The numerical examples show that the proposed formulation alleviates locking and yields good accuracy for various thicknesses, even for slenderness ratios of $1 \times 10^5$, and has the ability to capture deformations of thin shells using relatively coarse meshes. From the detailed numerical study, it can be opined that the proposed method is less sensitive to locking and mesh distortion. [less ▲] Detailed reference viewed: 73 (9 UL)Democratic legitimacy [glossary] Chiocchetti, Paolo E-print/Working paper (2017) A political institution is legitimate when it succeeds in persuading people of the normative necessity of its existence. In a democratic system, this can be based both on various forms of popular consent ... [more ▼] A political institution is legitimate when it succeeds in persuading people of the normative necessity of its existence. In a democratic system, this can be based both on various forms of popular consent (democratic legitimacy) and on other kinds of foundations (generic legitimacy). With reference to the European Union, debates have focused on empirical support for the EU, the nature of its "democratic deficit", and the potential conflict between European integration and national democratic sovereignty. [less ▲] Detailed reference viewed: 6 (0 UL)Evolution systems of measures and semigroup properties on evolving manifolds Cheng, Li Juan ; Thalmaier, Anton E-print/Working paper (2017) An evolving Riemannian manifold (M,g_t)_{t\in I} consists of a smooth d-dimensional manifold M, equipped with a geometric flow g_t of complete Riemannian metrics, parametrized by I=(-\infty,T). Given an ... [more ▼] An evolving Riemannian manifold (M,g_t)_{t\in I} consists of a smooth d-dimensional manifold M, equipped with a geometric flow g_t of complete Riemannian metrics, parametrized by I=(-\infty,T). Given an additional C^{1,1} family of vector fields (Z_t)_{t\in I} on M. We study the family of operators L_t=\Delta_t +Z_t where \Delta_t denotes the Laplacian with respect to the metric g_t. We first give sufficient conditions, in terms of space-time Lyapunov functions, for non-explosion of the diffusion generated by L_t, and for existence of evolution systems of probability measures associated to it. Coupling methods are used to establish uniqueness of the evolution systems under suitable curvature conditions. Adopting such a unique system of probability measures as reference measures, we characterize supercontractivity, hypercontractivity and ultraboundedness of the corresponding time-inhomogeneous semigroup. To this end, gradient estimates and a family of (super-)logarithmic Sobolev inequalities are established. [less ▲] Detailed reference viewed: 39 (17 UL)Koszul-Tate resolutions as cofibrant replacements of algebras over differential operators ; Pistalo, Damjan ; Poncin, Norbert E-print/Working paper (2017) Detailed reference viewed: 36 (1 UL)On Koszul-Tate resolutions and Sullivan models Pistalo, Damjan ; Poncin, Norbert E-print/Working paper (2017) Detailed reference viewed: 31 (1 UL)Arbeitsmotivation von Arbeitnehmern in Luxemburg Sischka, Philipp ; Steffgen, Georges E-print/Working paper (2017) Die europäische Studie EWCS (Eurofund, 2016a, 2016b) zeigt auf, dass sich die Arbeitsmotivation der Arbeitnehmer in Luxemburg eher im mittleren Bereich wiederfindet. Die nationale Studie Quality of Work ... [more ▼] Die europäische Studie EWCS (Eurofund, 2016a, 2016b) zeigt auf, dass sich die Arbeitsmotivation der Arbeitnehmer in Luxemburg eher im mittleren Bereich wiederfindet. Die nationale Studie Quality of Work Index belegt nur geringfügige Unterschiede der Arbeitsmotivation sowohl zwischen männlichen und weiblichen Arbeitnehmern als auch zwischen den verschiedenen Altersgruppen. Arbeitnehmer in einer Vorgesetztenposition, Manager und Führungskräfte zeigen im Durchschnitt eine höhere, Hilfsarbeitskräfte dagegen im Durchschnitt eine geringere Arbeitsmotivation. Überdurchschnittlich motiviert erweisen sich Arbeitnehmer in Nichtregierungsorganisationen (NGO). Die Arbeitsmotivation ist dabei mit verschiedenen psychosozialen Abeitsbedingungen sowie Arbeitsrahmenbedingungen korreliert. Parizipation an Entscheidungen, Feedback von Kollegen und Vorgesetzten, Kooperation unter Kollegen sowie Rollenklarheit sind positiv mit Arbeitsmotivation assoziert, das Erleben von Konkurrenz und Mobbing sind hingegen negativ assoziiert. Hinsichtlich Arbeitsrahmenbedingungen weist vor allem Arbeitsplatzsicherheit einen hohen Zusammenhang mit der Arbeitsmotivation auf, gefolgt von Einkommenszufriedenheit und Ausbildungsmöglichkeiten. [less ▲] Detailed reference viewed: 29 (2 UL)Herman Van Rompuy [biography] Chiocchetti, Paolo E-print/Working paper (2017) Herman Van Rompuy (b. 1947) is a Belgian and European politician. In his capacity as President of the European Council (2009-2014), he played a key role in the EU's response to the financial crisis and in ... [more ▼] Herman Van Rompuy (b. 1947) is a Belgian and European politician. In his capacity as President of the European Council (2009-2014), he played a key role in the EU's response to the financial crisis and in the strengthening of the European framework of economic governance. [less ▲] Detailed reference viewed: 3 (0 UL)Wolfgang Schäuble [biography] Chiocchetti, Paolo E-print/Working paper (2017) Wolfgang Schäuble (b. 1942) is an active German politician. He played a key role in the German reunification process (1989-90) and in the management of the Eurozone crisis (since 2009). Detailed reference viewed: 4 (0 UL)Solidarity [glossary] Chiocchetti, Paolo E-print/Working paper (2017) The principle of solidarity plays a key role in discussions of social, economic, and political issues. A polysemic notion, it may interrogate either individuals or public authorities. It often represents ... [more ▼] The principle of solidarity plays a key role in discussions of social, economic, and political issues. A polysemic notion, it may interrogate either individuals or public authorities. It often represents the counterpart of competition in the analysis and assessment of social norms and public policies. [less ▲] Detailed reference viewed: 5 (0 UL)Who Trade at Better Prices? Wolff, Christian ; E-print/Working paper (2017) Detailed reference viewed: 9 (0 UL)Localisation résidentielle de la population étrangère selon la nationalité et la structure urbaine au Luxembourg Pigeron-Piroth, Isabelle ; Heinz, Andreas ; Caruso, Geoffrey E-print/Working paper (2017) The number of foreigners living in Luxembourg is still rising and represents today about 48% of the inhabitants. This study focuses on the description and mapping of the place of residence for the ... [more ▼] The number of foreigners living in Luxembourg is still rising and represents today about 48% of the inhabitants. This study focuses on the description and mapping of the place of residence for the different nationalities living in Luxembourg. It seeks to underline differences through indicators built from the 2011 census data. We focus on the territorial distribution of the different nationalities by taking into account the urban structure and distance to jobs. If differences according to nationalities in the residential behavior of households can be empirically identified they may raise issues of spatial equity and (un)equal accessibility to job market. We analyse whether the geographic location of different nationalities in Luxembourg is linked to urbanisation level, the distance to the “poles d´emploi” or general accessibility to jobs. [less ▲] Detailed reference viewed: 29 (2 UL)The European Commission’s "Reflection Paper on Harnessing Globalisation" Chiocchetti, Paolo E-print/Working paper (2017) The new EC reflection paper on globalisation sets new accents, but contains no major departure from current policy orientations. It takes a clear stand for free trade, while attacking "unfair competition ... [more ▼] The new EC reflection paper on globalisation sets new accents, but contains no major departure from current policy orientations. It takes a clear stand for free trade, while attacking "unfair competition" and arguing for a "balanced, rules-based and progressive trade and investment agenda". Despite its insistence on a managed globalisation and a fair redistribution of its benefits, its proposals are unlikely to allay domestic anxieties and external criticism. [less ▲] Detailed reference viewed: 6 (1 UL)Cross-border mergers and acquisitions: Evidence from Indochina Wolff, Christian E-print/Working paper (2017) Detailed reference viewed: 5 (0 UL)State of the Art in Lightweight Symmetric Cryptography Biryukov, Alex ; Perrin, Léo Paul E-print/Working paper (2017) Lightweight cryptography has been one of the ``hot topics'' in symmetric cryptography in the recent years. A huge number of lightweight algorithms have been published, standardized and/or used in ... [more ▼] Lightweight cryptography has been one of the ``hot topics'' in symmetric cryptography in the recent years. A huge number of lightweight algorithms have been published, standardized and/or used in commercial products. In this paper, we discuss the different implementation constraints that a ``lightweight'' algorithm is usually designed to satisfy. We also present an extensive survey of all lightweight symmetric primitives we are aware of. It covers designs from the academic community, from government agencies and proprietary algorithms which were reverse-engineered or leaked. Relevant national (\nist{}...) and international (\textsc{iso/iec}...) standards are listed. We then discuss some trends we identified in the design of lightweight algorithms, namely the designers' preference for \arx{}-based and bitsliced-S-Box-based designs and simple key schedules. Finally, we argue that lightweight cryptography is too large a field and that it should be split into two related but distinct areas: \emph{ultra-lightweight} and \emph{IoT} cryptography. The former deals only with the smallest of devices for which a lower security level may be justified by the very harsh design constraints. The latter corresponds to low-power embedded processors for which the \aes{} and modern hash function are costly but which have to provide a high level security due to their greater connectivity. [less ▲] Detailed reference viewed: 127 (4 UL)La restructuration des dettes publiques saisie par le droit de l'Union européenne Allemand, Frederic E-print/Working paper (2017) En juillet 2015, le sommet de la zone euro fait part de l'existence de "sérieux doutes" sur le caractère soutenable de la dette grecque. La possibilité d'un reprofilage de la dette est envisagé et sa ... [more ▼] En juillet 2015, le sommet de la zone euro fait part de l'existence de "sérieux doutes" sur le caractère soutenable de la dette grecque. La possibilité d'un reprofilage de la dette est envisagé et sa discussion reportée à la réalisation de la première évaluation des mesures d'ajustement mises en oeuvre par la Grèce. Toute décote nominale est cependant formellement exclue, car contraire au droit de l'Union. Les discussions se sont ouvertes au printemps 2016 sur les modalités d'allègement de la dette publique de la Grèce. Le sujet a été au coeur de la réunion de l'Eurogroupe du 22 mai. Aucun accord n'a été trouvé, mais les discussions continuent. Dans ce contexte, Frédéric Allemand a présenté le 17 mai dernier une communication sur la saisine des opérations de restructuration par le droit de l'Union lors du séminaire de recherche pluridisciplinaire "Les administrations publiques à l'épreuve de leur dette" organisé par Jean-François Boudet (Université Paris II) et Caroline Lequesne-Roth (Université de Nice). L'auteur conclut à la compétence de l'Union pour encadrer la restructuration des dettes publiques des États membres. [less ▲] Detailed reference viewed: 18 (0 UL)Understanding audit oversight transformation : ramifications of institutional work and the power of (de-)mythologizing ; Muessig, Anke E-print/Working paper (2017) This study investigates the dynamics that transformed audit oversight in Germany from an instrument, organized by the profession, to maintain international legitimacy into a regulatory regime that is ... [more ▼] This study investigates the dynamics that transformed audit oversight in Germany from an instrument, organized by the profession, to maintain international legitimacy into a regulatory regime that is integrated into the state apparatus. While prior research has focused on countries where the global demand for oversight structures overlapped with local pressures for regulatory reforms, we examine the diffusion of patterns of control within a context that is characterized by a strong mythologized belief in the German qualified statutory auditor and professional self-regulation. By analysing archival documents and interviews with key actors, we investigate through the lens of institutional work how initially the audit establishment maintained the existing self-regulatory logic despite, and because of, the implementation of formal independent oversight structures. We illustrate how the institutional work of small auditors aimed at disrupting the large audit firms’ field dominance unintentionally undermined the mythologized self-regulation. In doing so, we offer insights into how institutional myth is both constructed and dismantled. Our focus on multiple actors allows us to shed light on how parallel institutional work of distinct actors can lead to mutually effective and unintended institutional consequences. We argue that a successful institutional worker executes a combination of two basic types of work, which we refer to as existential and instrumental modes of work. Finally, comparing our findings with literature on audit oversight in other countries allows us to conceptualize audit oversight along a political-operational dimension and a public-private dimension. [less ▲] Detailed reference viewed: 11 (0 UL)Gesundheitsverhalten von Arbeitnehmern in Luxemburg Sischka, Philipp ; Steffgen, Georges E-print/Working paper (2017) Insbesonders unter den jüngeren Arbeitnehmern und unter den Arbeitnehmern mit geringer Bildung ist der Anteil der Raucher vergleichsweise hoch. Männliche und ältere Arbeitnehmer weisen wieder einen ... [more ▼] Insbesonders unter den jüngeren Arbeitnehmern und unter den Arbeitnehmern mit geringer Bildung ist der Anteil der Raucher vergleichsweise hoch. Männliche und ältere Arbeitnehmer weisen wieder einen vergleichsweise hohen Alkoholkonsum auf. Differenziert nach Berufsgruppen zeigen vor allem Arbeitnehmer in Handwerksberufen sowie Manager und Führungskräfte einen hohen Alkoholkonsum. Die Arbeitnehmer in der jüngsten Altersgruppe (16 bis 24 Jährige) schlafen durchschnittlich etwas länger, im Vergleich zu den älteren Arbeitnehmern. Außerdem ist die Sporthäufigkeit in der jüngsten Altersgruppe am höchsten. Männliche Arbeitnehmer sowie Arbeitnehmer ohne Partner oder ohne Kinder treiben ebenfalls überduchschnittlich häufig Sport. Etwa 17% der Arbeitnehmer leidet unter Adipositas. Knapp 30% der Arbeitnehmer leidet manchmal oder häufiger an gesundheitlichen Problemen. Unter den gesundheitlichen Problemen sind Rückenprobleme besonders häufig, gefolgt von Schlafschwierigkeiten und Kopfschmerzen. Herzprobleme sind dagegen eher selten ausgeprägt. Arbeitnehmer mit Hochschulabschluss sowie Manager und Führungskräfte sind seltener von Gesundheitsproblemen betroffen. Gesundheitliche Probleme sind insgesamt mit Zigarettenkonsum, Schlafstunden pro Tag, Sporthäufigkeit und Body Mass Index assoziiert: Je weniger geraucht wird, je mehr geschlafen und Sport getrieben wird und je geringer das körperliche Gewicht der Arbeitnehmer, desto weniger Gesundheitsprobleme liegen tendenziell vor. [less ▲] Detailed reference viewed: 29 (3 UL)The economic programme of Emmanuel Macron Chiocchetti, Paolo E-print/Working paper (2017) The outsider Emmanuel Macron is the winner of the first round of the French presidential election. His economic programme is betting on a strategy of fiscal consolidation, tax cuts, targeted investments ... [more ▼] The outsider Emmanuel Macron is the winner of the first round of the French presidential election. His economic programme is betting on a strategy of fiscal consolidation, tax cuts, targeted investments, and further Europeanisation. Success crucially hinges on the outcome of the June legislative elections and on a favourable evolution of the global economic environment. [less ▲] Detailed reference viewed: 3 (0 UL)Scaling evidence of the homothetic nature of cities Lemoy, Rémi ; Caruso, Geoffrey E-print/Working paper (2017) In this paper we analyse the profile of land use and population density with respect to the distance to the city centre for the European city. In addition to providing the radial population density and ... [more ▼] In this paper we analyse the profile of land use and population density with respect to the distance to the city centre for the European city. In addition to providing the radial population density and soil-sealing profiles for a large set of cities, we demonstrate a remarkable constancy of the profiles across city size. Our analysis combines the GMES/Copernicus Urban Atlas 2006 land use database at 5m resolu- tion for 300 European cities with more than 100.000 inhabitants and the Geostat population grid at 1km resolution. Population is allocated proportionally to surface and weighted by soil sealing and density classes of the Urban Atlas. We analyse the profile of each artificial land use and population with distance to the town hall. In line with earlier literature, we confirm the strong monocentricity of the European city and the negative exponential curve for population density. Moreover, we find that land use curves, in particular the share of housing and roads, scale along the two horizontal dimensions with the square root of city population, while population curves scale in three dimensions with the cubic root of city population. In short, European cities of different sizes are homothetic in terms of land use and population density. While earlier literature documented the scaling of average densities (total surface and population) with city size, we document the scaling of the whole radial distance profile with city size, thus liaising intra-urban radial analysis and systems of cities. In addition to providing a new empirical view of the European city, our scaling offers a set of practical and coherent definitions of a city, independent of its population, from which we can re-question urban scaling laws and Zipf’s law for cities. [less ▲] Detailed reference viewed: 27 (1 UL)Benelux, Europe and the Cold War, the power of non-powers Paravantis, Spero E-print/Working paper (2017) The conference “Benelux, Europe and the Cold War, the power of non-powers”, which took place on 30 and 31 March 2017 at the University of Luxembourg, was the first of three events planned in the FNR ... [more ▼] The conference “Benelux, Europe and the Cold War, the power of non-powers”, which took place on 30 and 31 March 2017 at the University of Luxembourg, was the first of three events planned in the FNR-funded CORE junior project “Benelux”, as part of its public outreach and academic output objectives. The conference sought to highlight asymmetrical power relations in the Cold War period of European integration by examining European security. What was/is European security in the context of the Cold War? How was and is it conceived? What role did “non-powers” play in European security, and how did they help define it? This conference investigated these and other related questions by re-examining the US/European relationship in the early Cold War and the role that developments during this period played in the European integration movement. In so doing, the conference also showcased findings which helped unify historiographies of the Cold War and European integration. [less ▲] Detailed reference viewed: 17 (1 UL)What makes Data Science different? A discussion involving Statistics2.0 and Computational Sciences ; Bordas, Stéphane E-print/Working paper (2017) Data Science is today one of the main buzzwords be it in business, industrial or academic settings. Machine learning, experimental design, data-driven modelling are all, undoubtedly, rising disciplines if ... [more ▼] Data Science is today one of the main buzzwords be it in business, industrial or academic settings. Machine learning, experimental design, data-driven modelling are all, undoubtedly, rising disciplines if one goes by the soaring number of research papers and patents appearing each year. The prospect of becoming a ``Data Scientist'' appeals to many. A discussion panel organised as part of the European Data Science Conference (European Association for Data Science (EuADS)) asked the question: ``What makes Data Science different?'' In this paper we give our own, personal and multi-facetted view on this question, from an engineering and a statistics perspective. In particular, we compare Data Science to Statistics and discuss the connection between Data Science and Computational Science. [less ▲] Detailed reference viewed: 333 (28 UL)Population ageing [glossary] Chiocchetti, Paolo E-print/Working paper (2017) Population ageing is a major trend in contemporary European societies. A consequence of welcome shifts in life expectancy and fertility, it nevertheless entails important challenges for the adequacy ... [more ▼] Population ageing is a major trend in contemporary European societies. A consequence of welcome shifts in life expectancy and fertility, it nevertheless entails important challenges for the adequacy, sustainability, and competitiveness of social and economic systems. [less ▲] Detailed reference viewed: 5 (0 UL)The maximum number of systoles for genus two Riemann surfaces with abelian differentials ; Parlier, Hugo E-print/Working paper (2017) This article explores the length and number of systoles associated to holomorphic $1$-forms on surfaces. In particular, we show that up to homotopy, there are at most $10$ systolic loops on such a genus ... [more ▼] This article explores the length and number of systoles associated to holomorphic $1$-forms on surfaces. In particular, we show that up to homotopy, there are at most $10$ systolic loops on such a genus two surface and that the bound is realized by a unique translation surface up to homothety. We also provide sharp upper bounds on the the number of homotopy classes of systoles for a holomorphic $1$-form with a single zero in terms of the genus. [less ▲] Detailed reference viewed: 25 (2 UL)Migration, Labor Tasks and Production Structure in Europe Joxhe, Majlinda ; ; E-print/Working paper (2017) This paper assesses the effect of the immigration on the production structure in a selection of European countries in 2001-2009 with a task-based approach. The inflow of immigrants represents an increase ... [more ▼] This paper assesses the effect of the immigration on the production structure in a selection of European countries in 2001-2009 with a task-based approach. The inflow of immigrants represents an increase in the relative supply of manual-physical (or simple) tasks, hence favoring simple-task intensive sectors. We use a new OECD dataset, PIAAC, to calculate the index of simple-task intensity at the country-industry level. The analysis confirms that the increase in migration stocks caused a positive impact on the value added of sectors that use more intensively simple tasks. These effects are more intense when considering countries as Italy and Spain characterized by a recent, rapid and intense inflow of migrants. Endogeneity issues are discussed and instruments based on a gravity approach are used in estimation. [less ▲] Detailed reference viewed: 34 (4 UL)Images of Galois representations in mod p Hecke algebras Amoros Carafi, Laia E-print/Working paper (2017) Detailed reference viewed: 19 (2 UL)C’était extrêmement violent» Il y a 100 ans, la révolution de Février a provoqué la fin de l’Empire russe Paravantis, Spero E-print/Working paper (2017) La révolution de Février, qui s'est déroulée du 8 mars (23 février) 1917 au 13 mars (28 février) 1917, marque le début de la révolution russe de 1917. Elle force l'abdication du tsar Nicolas II et ... [more ▼] La révolution de Février, qui s'est déroulée du 8 mars (23 février) 1917 au 13 mars (28 février) 1917, marque le début de la révolution russe de 1917. Elle force l'abdication du tsar Nicolas II et provoque la fin de l'Empire russe. Un gouvernement provisoire dirige, mais la même année, la révolution d'Octobre met au pouvoir des bolcheviks et permet la création de l'Union des républiques socialistes soviétiques (URSS). Le chercheur au «Centre for Contemporary and Digital History» à l’Université du Luxembourg, Dr. Spero S.Z. Paravantis nous détaille ce chapitre de l’histoire. [less ▲] Detailed reference viewed: 24 (8 UL)Wohlbefinden von Arbeitnehmern in Luxemburg Sischka, Philipp ; Steffgen, Georges E-print/Working paper (2017) Vergleicht man die Teilnehmer der Quality of Work Index Luxembourg Umfrage mit anderen europäischen Arbeitnehmern, zeigen die Teilnehmer aus Luxemburg im Durchschnitt ein geringeres Wohlbefinden ... [more ▼] Vergleicht man die Teilnehmer der Quality of Work Index Luxembourg Umfrage mit anderen europäischen Arbeitnehmern, zeigen die Teilnehmer aus Luxemburg im Durchschnitt ein geringeres Wohlbefinden. Insbesondere jüngere Arbeitnehmer weisen ein tendenziell geringeres Wohlbefinden auf. Differenziert man die Arbeitnehmer nach Berufsgruppen, zeigen Manager und Führungskräfte, Arbeitnehmer in Dienstleistungsberufen sowie Hilfsarbeitskräfte das höchste Wohlbefinden. Arbeitnehmer mit geringeren faktischen Wochenstundenzahlen sowie Arbeitnehmer, die in kleinen Betrieben (1-4 Beschäftigte) arbeiten, berichten über ein höheres Wohlbefinden. Das Wohlbefinden ist hierbei nachweislich mit unterschiedlichen Arbeitsbedingungen assoziiert. So weisen Arbeitnehmer, je höher ihre Partizipation, ihre Rollenklarheit bei der Arbeit sowie ihre Arbeitsplatzsicherheit ist umso ein höheres Wohlbefinden auf. Das Wohlbefinden ist außerdem positiv mit Arbeitszufriedenheit, wahrgenommenem Respekt bei der Arbeit und negativ mit Stress und Burnout korreliert. [less ▲] Detailed reference viewed: 36 (9 UL)How did the ECB become a fully-fledged central bank of the eurozone? Gren, Jakub E-print/Working paper (2017) Detailed reference viewed: 57 (4 UL)Real-time Error Control for Surgical Simulation Bui, Huu Phuoc ; Tomar, Satyendra ; Bordas, Stéphane E-print/Working paper (2017) Real-time simulations are becoming increasingly common for various applications, from geometric design to medical simulation. Two of the main factors concurrently involved in defining the accuracy of ... [more ▼] Real-time simulations are becoming increasingly common for various applications, from geometric design to medical simulation. Two of the main factors concurrently involved in defining the accuracy of surgical simulations are: the modeling error and the discretization error. Most work in the area has been looking at the above sources of error as a compounded, lumped, overall error. Little or no work has been done to discriminate between modeling error (e.g. needle-tissue interaction, choice of constitutive models) and discretization error (use of approximation methods like FEM). However, it is impossible to validate the complete surgical simulation approach and, more importantly, to understand the sources of error, without evaluating both the discretization error and the modeling error. Our objective is thus to devise a robust and fast approach to measure the discretization error via a posteriori error estimates, which are then used for local remeshing in surgical simulations. To ensure that the approach can be used in clinical practice, the method should be robust enough to deal, as realistically as possible, with the interaction of surgical tools with the organ, and fast enough for real-time simulations. The approach should also lead to an improved convergence so that an economical mesh is obtained at each time step. The final goal is to achieve optimal convergence and the most economical mesh, which will be studied in our future work. [less ▲] Detailed reference viewed: 221 (20 UL)Evaluating How Child Allowances and Daycare Subsidies Affect Fertility ; Koulovatianos, Christos ; et al E-print/Working paper (2017) We compare the cost effectiveness of two pronatalist policies: (a) child allowances; and (b) daycare subsidies. We pay special attention to estimating how intended fertility (fertility before children are ... [more ▼] We compare the cost effectiveness of two pronatalist policies: (a) child allowances; and (b) daycare subsidies. We pay special attention to estimating how intended fertility (fertility before children are born) responds to these policies. We use two evaluation tools: (i) a dynamic model on fertility, labor supply, outsourced childcare time, parental time, asset accumulation and consumption; and (ii) randomized vignette-survey policy experiments. We implement both tools in the United States and Germany, finding consistent evidence that daycare subsidies are more cost effective. Nevertheless, the required public expenditure to increase fertility to the replacement level might be viewed as prohibitively high. [less ▲] Detailed reference viewed: 31 (3 UL)Populism [glossary] Chiocchetti, Paolo E-print/Working paper (2017) A chameleonic concept, populism can be defined as an ideology, a communication style, a political strategy, or a misguided category. Its key elements are a positive appreciation of people, a negative view ... [more ▼] A chameleonic concept, populism can be defined as an ideology, a communication style, a political strategy, or a misguided category. Its key elements are a positive appreciation of people, a negative view of the elite, and the exaltation of untrammeled popular sovereignty against representative democracy and liberal constitutionalism. The fortune of the term, despite its theoretical and practical drawbacks, is the reflection of intrinsic antinomies of modern democracy and of a growing popular dissatisfaction toward the performance of representative governments and institutions. [less ▲] Detailed reference viewed: 8 (0 UL)Bayesian inference for the stochastic identification of elastoplastic material parameters: Introduction, misconceptions and insights Rappel, Hussein ; Beex, Lars ; Hale, Jack et al E-print/Working paper (2017) We discuss Bayesian inference (BI) for the probabilistic identification of material parameters. This contribution aims to shed light on the use of BI for the identification of elastoplastic material ... [more ▼] We discuss Bayesian inference (BI) for the probabilistic identification of material parameters. This contribution aims to shed light on the use of BI for the identification of elastoplastic material parameters. For this purpose a single spring is considered, for which the stress-strain curves are artificially created. Besides offering a didactic introduction to BI, this paper proposes an approach to incorporate statistical errors both in the measured stresses, and in the measured strains. It is assumed that the uncertainty is only due to measurement errors and the material is homogeneous. Furthermore, a number of possible misconceptions on BI are highlighted based on the purely elastic case. [less ▲] Detailed reference viewed: 193 (56 UL)Institutional Determinants of Early Job Insecurity in Nine European Countries: Country Report Switzerland ; ; et al E-print/Working paper (2017) An overview of institutional determinants of early job insecurity in Switzerland. Detailed reference viewed: 10 (3 UL)Chromatic numbers for the hyperbolic plane and discrete analogs Parlier, Hugo ; E-print/Working paper (2017) We study colorings of the hyperbolic plane, analogously to the Hadwiger-Nelson problem for the Euclidean plane. The idea is to color points using the minimum number of colors such that no two points at ... [more ▼] We study colorings of the hyperbolic plane, analogously to the Hadwiger-Nelson problem for the Euclidean plane. The idea is to color points using the minimum number of colors such that no two points at distance exactly $d$ are of the same color. The problem depends on $d$ and, following a strategy of Kloeckner, we show linear upper bounds on the necessary number of colors. In parallel, we study the same problem on $q$-regular trees and show analogous results. For both settings, we also consider a variant which consists in replacing $d$ with an interval of distances. [less ▲] Detailed reference viewed: 17 (1 UL)Quantum moment maps and retracts for bounded symmetric domains Korvers, Stéphane E-print/Working paper (2017) Detailed reference viewed: 21 (2 UL)The Turkish State of Emergency Under Turkish Constitutional Law and International Human Rights Law Baglayan Ceyhan, Basak E-print/Working paper (2017) Detailed reference viewed: 64 (1 UL)Wealth accumulation over the life course. The role of disadvantages across the employment history Ponomarenko, Valentina E-print/Working paper (2017) In this study wealth is employed as an often neglected but highly stratified well-being measure in sociology. I relate the employment history and especially the accumulating disadvantages like ... [more ▼] In this study wealth is employed as an often neglected but highly stratified well-being measure in sociology. I relate the employment history and especially the accumulating disadvantages like nonemployment and lower occupations to wealth in old age. In particular, I am interested in determining whether an adverse employment history prevents wealth accumulation and which factors influence wealth accumulation across the life course. I use comparative data from the Survey of Health, Ageing and Retirement and combine it with the retrospective panel SHARELIFE to retrieve information about the complete employment history. The relevance of wealth varies significantly across households and in the wider national context. Hence, a contextual perspective is included to account for the difference in wealth rates and wealth inequality in the European countries. The results show that cumulative nonemployment and employment in lower occupations has significant disadvantages for wealth accumulation in old age. However, large differences for men and women persist. Particularly, the household composition and household factors are decisive in the effectuality of these disadvantages. The relation of life course employment and especially disadvantages to accumulated wealth in old aged is stronger in conservative countries than in other welfare regimes. [less ▲] Detailed reference viewed: 112 (2 UL)Entropy degeneration of globally hyperbolic maximal compact anti-de Sitter structures Tamburelli, Andrea E-print/Working paper (2017) Using the parameterisation of the deformation space of GHMC anti-de Sitter structures on S×ℝ by the cotangent bundle of the Teichmüller space of S, we study how some geometric quantities, such as the ... [more ▼] Using the parameterisation of the deformation space of GHMC anti-de Sitter structures on S×ℝ by the cotangent bundle of the Teichmüller space of S, we study how some geometric quantities, such as the Lorentzian Hausdorff dimension of the limit set, the width of the convex core and the Hölder exponent, degenerate along rays of quadratic differentials. [less ▲] Detailed reference viewed: 6 (0 UL)Monotonicity of probit weights ; Tripathi, Gautam E-print/Working paper (2017) Detailed reference viewed: 21 (1 UL)Integrated likelihood based inference for nonlinear panel data models with unobserved effects Schumann, Martin ; ; Tripathi, Gautam E-print/Working paper (2017) Detailed reference viewed: 37 (4 UL)Constant mean curvature foliation of globally hyperbolic (2+1)-spacetime with particles ; Tamburelli, Andrea E-print/Working paper (2017) Let M be a globally hyperbolic maximal compact 3-dimensional spacetime locally modelled on Minkowski, anti-de Sitter or de Sitter space. It is well known that M admits a unique foliation by constant mean ... [more ▼] Let M be a globally hyperbolic maximal compact 3-dimensional spacetime locally modelled on Minkowski, anti-de Sitter or de Sitter space. It is well known that M admits a unique foliation by constant mean curvature surfaces. In this paper we extend this result to singular spacetimes with particles (cone singularities of angles less than π along time-like geodesics). [less ▲] Detailed reference viewed: 14 (0 UL)Identifying individual rights in EU law Hofmann, Herwig ; Warin, Catherine E-print/Working paper (2017) Detailed reference viewed: 40 (4 UL)Recurrence and Transience of Frogs with Drift on Z^d Döbler, Christian ; ; et al E-print/Working paper (2017) Detailed reference viewed: 8 (0 UL)Quantitative C1-estimates by Bismut formulae Cheng, Li Juan ; Thalmaier, Anton ; Thompson, James E-print/Working paper (2017) For a C2 function u and an elliptic operator L, we prove a quantitative estimate for the derivative du in terms of local bounds on u and Lu. An integral version of this estimate is then used to derive a ... [more ▼] For a C2 function u and an elliptic operator L, we prove a quantitative estimate for the derivative du in terms of local bounds on u and Lu. An integral version of this estimate is then used to derive a condition for the zero-mean value property of Δu. An extension to differential forms is also given. Our approach is probabilistic and could easily be adapted to other settings. [less ▲] Detailed reference viewed: 60 (10 UL)On the fourth moment condition for Rademacher chaos Döbler, Christian ; E-print/Working paper (2017) Detailed reference viewed: 28 (1 UL)Derivative and divergence formulae for diffusion semigroups Thalmaier, Anton ; Thompson, James E-print/Working paper (2017) Detailed reference viewed: 109 (27 UL)Harnack estimates for a nonlinear parabolic equation under Ricci flow Li, Yi ; E-print/Working paper (2017) Detailed reference viewed: 40 (1 UL)Freeness characterisations on free chaos spaces Bourguin, Solesne ; Nourdin, Ivan E-print/Working paper (2017) Detailed reference viewed: 17 (0 UL)La représentation de la littérature de la Lorraine dans l'espace - utilisation d'un système d'information géographique via Internet Helfer, Malte E-print/Working paper (2017) Detailed reference viewed: 6 (0 UL)Eulerian idempotent, pre-Lie logarithm and combinatorics of trees ; Schätz, Florian E-print/Working paper (2017) The aim of this paper is to bring together the three objects in the title. Recall that, given a Lie algebra g, the Eulerian idempotent is a canonical projection from the enveloping algebra U(g) to g. The ... [more ▼] The aim of this paper is to bring together the three objects in the title. Recall that, given a Lie algebra g, the Eulerian idempotent is a canonical projection from the enveloping algebra U(g) to g. The Baker-Campbell-Hausdorff product and the Magnus expansion can both be expressed in terms of the Eulerian idempotent, which makes it interesting to establish explicit formulas for the latter. We show how to reduce the computation of the Eulerian idempotent to the computation of a logarithm in a certain pre-Lie algebra of planar, binary, rooted trees. The problem of finding formulas for the pre-Lie logarithm, which is interesting in its own right – being related to operad theory, numerical analysis and renormalization – is addressed using techniques inspired by umbral calculus. As a consequence of our analysis, we find formulas both for the Eulerian idempotent and the pre-Lie logarithm in terms of the combinatorics of trees. [less ▲] Detailed reference viewed: 12 (0 UL)The Spectrum Of De Novo Variants In Neurodevelopmental Disorders With Epilepsy ; ; et al E-print/Working paper (2017) Neurodevelopmental disorders (NDD) with epilepsy constitute a complex and heterogeneous phenotypic spectrum of largely unclear genetic architecture. We conducted exome-wide enrichment analyses for protein ... [more ▼] Neurodevelopmental disorders (NDD) with epilepsy constitute a complex and heterogeneous phenotypic spectrum of largely unclear genetic architecture. We conducted exome-wide enrichment analyses for protein-altering de novo variants (DNV) in 7088 parent-offspring trios with NDD of which 2151 were comorbid with epilepsy. In this cohort, the genetic spectrum of epileptic encephalopathy (EE) and nonspecific NDD with epilepsy were markedly similar. We identified 33 genes significantly enriched for DNV in NDD with epilepsy, of which 27.3 were associated with therapeutic consequences. These 33 DNV-enriched genes were more often associated with synaptic transmission but less with chromatin modification when compared to NDD without epilepsy. On average, only 53 of the DNV-enriched genes were represented on available diagnostic sequencing panels, so our findings should drive significant improvements of genetic testing approaches. [less ▲] Detailed reference viewed: 91 (2 UL)Times of Crisis, Times of Prospects: Can the EU Learn from the 1970s? Herzog, Mechthild E-print/Working paper (2017) Detailed reference viewed: 3 (0 UL)Grenzüberschreitende Alltagspraktiken in der Großregion SaarLorLux Wille, Christian ; Pauly, Michel ; Caruso, Geoffrey et al E-print/Working paper (2017) In diesem Beitrag werden Alltagspraktiken untersucht, die von den Einwohnern des Saarlandes, Lothringens, Luxemburgs, von Rheinland-Pfalz und Wallonien in angrenzenden Regionen im Ausland ausgeführt ... [more ▼] In diesem Beitrag werden Alltagspraktiken untersucht, die von den Einwohnern des Saarlandes, Lothringens, Luxemburgs, von Rheinland-Pfalz und Wallonien in angrenzenden Regionen im Ausland ausgeführt werden. Dafür leitend ist die Überlegung, dass sich die Großregion SaarLorLux anhand der grenzüberschreitenden Ausführungen von Alltagspraktiken ihrer Bewohner als grenzüberschreitende Lebenswirklichkeit bestimmen lässt. In einer solchen sozialkonstruktivistischen Perspektive wird nicht danach gefragt, was die Großregion SaarLorLux ist, sondern auf welche Weisen sie konstituiert wird bzw. wie sie sich im Alltag ihrer Bewohner manifestiert. [less ▲] Detailed reference viewed: 12 (2 UL)Sub-Laplacian comparison theorems on totally geodesic Riemannian foliations ; ; et al E-print/Working paper (2017) We develop a variational theory of geodesics for the canonical variation of the metric of a totally geodesic foliation. As a consequence, we obtain comparison theorems for the horizontal and vertical ... [more ▼] We develop a variational theory of geodesics for the canonical variation of the metric of a totally geodesic foliation. As a consequence, we obtain comparison theorems for the horizontal and vertical Laplacians. In the case of Sasakian foliations, we show that sharp horizontal and vertical comparison theorems for the sub-Riemannian distance may be obtained as a limit of horizontal and vertical comparison theorems for the Riemannian distances approximations. [less ▲] Detailed reference viewed: 26 (3 UL)Homotopical algebraic context over differential operators ; Pistalo, Damjan ; Poncin, Norbert E-print/Working paper (2017) Detailed reference viewed: 37 (6 UL)Reassessment Of Lesion-Associated Gene And Variant Pathogenicity In Focal Human Epilepsies ; ; May, Patrick et al E-print/Working paper (2017) Purpose: Increasing availability of surgically resected brain tissue from Focal Cortical Dysplasia and low-grade epilepsy-associated tumor patients fostered large-scale genetic examination. However ... [more ▼] Purpose: Increasing availability of surgically resected brain tissue from Focal Cortical Dysplasia and low-grade epilepsy-associated tumor patients fostered large-scale genetic examination. However, assessment of germline and somatic variant pathogenicity remains difficult. Methods: Here, we critically reevaluated the pathogenicity for all neuropathology-associated variants reported to date in the PubMed and ClinVar databases, including 12 disease-related genes and 88 neuropathology-associated missense variants. We (1) assessed evolutionary gene constraint using the pLI and missense z scores, (2) applied guidelines by the American College of Medical Genetics and Genomics (ACMG), and (3) predicted pathogenicity by using PolyPhen-2, CADD, and GERP. Results: Constraint analysis classified only seven out of 12 genes to be likely disease-associated, while 35 (40\%) of those 88 variants were classified as being variants of unknown significance (VUS) and 53 (60\%) as being likely pathogenic (LPII). Pathogenicity prediction yielded discrimination between neuropathology-associated variants (LPII and VUS) and rare variant scores obtained from individuals present in the Genome Aggregation Database (gnomAD). Conclusion: We conclude that several VUS are likely disease-associated and will be reclassified by future molecular evidence. In summary, interpretation of lesion-associated gene variants remains complex while the application of current ACMG guidelines including bioinformatic pathogenicity prediction will help improving interpretation and prediction. [less ▲] Detailed reference viewed: 36 (1 UL)The fourth moment theorem on the Poisson space Döbler, Christian ; Peccati, Giovanni E-print/Working paper (2017) Detailed reference viewed: 70 (5 UL)Conformal actions of real-rank 1 simple Lie groups on pseudo-Riemannian manifolds Pecastaing, Vincent E-print/Working paper (2017) Given a simple Lie group G of rank 1, we consider compact pseudo-Riemannian manifolds (M,g) of signature (p,q) on which G can act conformally. Precisely, we determine the smallest possible value for the ... [more ▼] Given a simple Lie group G of rank 1, we consider compact pseudo-Riemannian manifolds (M,g) of signature (p,q) on which G can act conformally. Precisely, we determine the smallest possible value for the index min(p,q) of the metric. When the index is optimal and G non-exceptional, we prove that the metric must be conformally flat, confirming the idea that in a "good" dynamical context, a geometry is determined by its automorphisms group. This completes anterior investigations on pseudo-Riemannian conformal actions of semi-simple Lie groups of maximal real-rank. Combined with these results, we obtain as corollary the list of semi-simple Lie groups without compact factor that can act on compact Lorentzian manifolds. We also derive consequences in CR geometry via the Fefferman fibration. [less ▲] Detailed reference viewed: 12 (3 UL)Quantifying the uncertainty in a hyperelastic soft tissue model with stochastic parameters Hauseux, Paul ; Hale, Jack ; et al E-print/Working paper (2017) We present a simple open-source semi-intrusive computational method to propagate uncertainties through hyperelastic models of soft tissues. The proposed method is up to two orders of magnitude faster than ... [more ▼] We present a simple open-source semi-intrusive computational method to propagate uncertainties through hyperelastic models of soft tissues. The proposed method is up to two orders of magnitude faster than the standard Monte Carlo method. The material model of interest can be altered by adjusting few lines of (FEniCS) code. The method is able to (1) provide the user with statistical confidence intervals on quantities of practical interest, such as the displacement of a tumour or target site in an organ; (2) quantify the sensitivity of the response of the organ to the associated parameters of the material model. We exercise the approach on the determination of a confidence interval on the motion of a target in the brain. We also show that for the boundary conditions under consideration five parameters of the Ogden-Holzapfel-like model have negligible influence on the displacement of the target zone compared to the three most influential parameters. The benchmark problems and all associated data are made available as supplementary material. [less ▲] Detailed reference viewed: 248 (53 UL)Asymptotic distribution of nodal intersections for arithmetic random waves Rossi, Maurizia ; E-print/Working paper (2017) Detailed reference viewed: 20 (0 UL)Explaining employers’ hiring decisions: A comparative study of employers’ risk assessment ; ; et al E-print/Working paper (2017) In order to investigate the scarring effect of early job insecurity on future employment chances we have implemented a factorial survey experiment with recruiters based on real vacancies in Bulgaria ... [more ▼] In order to investigate the scarring effect of early job insecurity on future employment chances we have implemented a factorial survey experiment with recruiters based on real vacancies in Bulgaria, Greece, Norway and Switzerland. We contribute to recruitment research at least in three ways: First, the multinational design allows us to run comparative analysis across countries, which are carried out along the national dimensions youth unemployment rate, employment protection regulation and type of educational system. Second, we differentiate between two different forms of early job insecurity – unemployment and work experience in deskilling jobs, and we demonstrate that the sole focus on unemployment, as it is the case in the prevalent labour market research, is not sufficient in order to fully understand labour market outcomes caused by different forms of job insecurities. Third, since our sample consists of real recruiters who were hiring for current jobs at the time when the study was carried out, we provide a unique cross-country data set of high external validity. Our findings suggest that scarring effects of early job insecurity vary across countries and across occupational fields, and while scarring caused by work experience in deskilling jobs seems to be enforced by strong employment protection regulations, unemployment scarring seems to stronger where national unemployment is low. Further, the differences in recruiter’s evaluation across occupational fields indicate that signalling value of education may vary depending on specific sectors. Not at least, we contribute to debates around active labour market policies, arguing that measures aiming at quick labour market reintegration without consideration of job quality may not be the most sustainable solution, as work experience in a deskilling job does not lead to better recruiter’s evaluation. [less ▲] Detailed reference viewed: 72 (3 UL)Liberté de circulation des personnes : citoyenneté de mouvement, citoyenneté en mouvement Warin, Catherine E-print/Working paper (2017) Detailed reference viewed: 11 (2 UL)Generalized Ricci flow II: Existence for complete noncompact manifolds Li, Yi E-print/Working paper (2017) Detailed reference viewed: 83 (7 UL)Deformations of pre-symplectic structures and the Koszul L-infty-algebra Schätz, Florian ; E-print/Working paper (2017) We study the deformation theory of pre-symplectic structures, i.e. closed two-forms of fixed rank. The main result is a parametrization of nearby deformations of a given pre-symplectic structure in terms ... [more ▼] We study the deformation theory of pre-symplectic structures, i.e. closed two-forms of fixed rank. The main result is a parametrization of nearby deformations of a given pre-symplectic structure in terms of an $L_\infty$-algebra, which we call the Koszul $L_\infty$-algebra. This $L_\infty$-algebra is a cousin of the Koszul dg Lie algebra associated to a Poisson manifold, and its proper geometric understanding relies on Dirac geometry. In addition, we show that a quotient of the Koszul $L_{\infty}$-algebra is isomorphic to the $L_\infty$-algebra which controls the deformations of the underlying characteristic foliation. Finally, we show that the infinitesimal deformations of pre-symplectic structures and of foliations are both obstructed. [less ▲] Detailed reference viewed: 7 (0 UL)Räumliche Identifikationen und Identifizierungen in Grenzregionen. Das Beispiel der Großregion SaarLorLux Wille, Christian E-print/Working paper (2017) In diesem Beitrag wird die Bedeutung von nationalen Grenzen für räumliche Identitäten in Grenzregionen analysiert. Dafür wird ein mehrdimensionales Analysemodell entwickelt und am Beispiel der Großregion ... [more ▼] In diesem Beitrag wird die Bedeutung von nationalen Grenzen für räumliche Identitäten in Grenzregionen analysiert. Dafür wird ein mehrdimensionales Analysemodell entwickelt und am Beispiel der Großregion SaarLorLux gefragt, wie die Einwohner den Raum repräsentieren und wie sie ihre alltagskulturellen Praktiken räumlich organisieren. Außerdem werden räumliche Projektionen im politischen Diskurs aufgedeckt und rekonstruiert, inwiefern diese eine Grundlage bilden für Identifizierungsprozesse. Der Beitrag zeigt, dass nationale Grenzen in den Identifikations- und Identifizierungsvorgängen der Einwohner der Großregion SaarLorLux trotz grenzüberschreitender Verflechtungen eine wichtige Rolle spielen, aber nicht zwangsläufig als starre Ordnungskategorien. [less ▲] Detailed reference viewed: 116 (14 UL)The Vanishing of Low-Dimensional Cohomology Groups of the Witt and the Virasoro algebra Ecker, Jill Marie-Anne ; Schlichenmaier, Martin E-print/Working paper (2017) A proof of the vanishing of the first and the third cohomology groups of the Witt algebra with values in the adjoint module is given. The proofs given in the present article are completely algebraic and ... [more ▼] A proof of the vanishing of the first and the third cohomology groups of the Witt algebra with values in the adjoint module is given. The proofs given in the present article are completely algebraic and independent of any underlying topology. They are a generalization of the ones provided by Schlichenmaier, who proved the vanishing of the second cohomology group using purely algebraic methods. In the case of the third cohomology group though, extra difficulties arise and the involved proofs are distinctly more complicated. [less ▲] Detailed reference viewed: 30 (0 UL)To MigrateWith orWithout Ones’ Children in China - That is the Question Chen, Yiwen ; ; et al E-print/Working paper (2017) Where should Chinese internal migrant parents locate their school-aged children: migrate with them or leave them behind? And should they invest in private education of their children? Empirical evidence ... [more ▼] Where should Chinese internal migrant parents locate their school-aged children: migrate with them or leave them behind? And should they invest in private education of their children? Empirical evidence based on the 2009 wave of the Rural-Urban Migration Survey in China (RUMiC) data is inconclusive. We use an overlapping generations model to find a theoretical optimum that maximizes parents’ utility which includes the children’s educational performance. Depending on the educational investment parents make and the relocation cost of children, we provide necessary and sufficient conditions for migrant parents to take their children to migrate and whether they should provide their children with private education. As the choices of migrant parents affect not only their children’s human capital accumulation, but also on the economic potential of their descendants, we present both short- and long-term consequences of the parents decision. [less ▲] Detailed reference viewed: 30 (3 UL)Fourth moment theorems on The Poisson space in any dimension Döbler, Christian ; Vidotto, Anna ; Zheng, Guangqu E-print/Working paper (2017) Detailed reference viewed: 40 (3 UL)Online deliberation: state of the art Kies, Raphaël E-print/Working paper (2017) In the last decade, the issue of online deliberation (or web-deliberation) has gained an important visibility among the scholars in the domain of political science, political philosophy, political ... [more ▼] In the last decade, the issue of online deliberation (or web-deliberation) has gained an important visibility among the scholars in the domain of political science, political philosophy, political communication as well as software designers. It corresponds not only to a topic of analysis – that can be broadly defined as the quantitative and qualitative assessment of the political and public debates online - but also to a democratic model of e-democracy, that aims to shape the different political usage of the web according to the deliberative values. A pertinent way to analyze this broad phenomenon is to subdivide its analysis in three sections which content is partly based on updated findings of my book Promises and Limits of web-deliberation. The first section refers to the deliberative theory on which the empirical research is based. The second section deals with the complex issue of operationalizing the deliberative theory. The last section provides an overview of the online deliberative empirical studies that were conducted this last decade by distinguishing three broad research fields: i) The studies that aim at measuring the usage of the political web-debates and the characteristics of the users; ii) The studies that identify and compare the social and political actors that offer possibilities of online debates; iii) The studies assessing the quality of deliberation in different discursive online settings and the ones aiming at defining the factors that could explain variations in web-deliberation. [less ▲] Detailed reference viewed: 55 (5 UL)Harnack estimates for a heat-type equation under the geometric flow Li, Yi ; E-print/Working paper (2017) Detailed reference viewed: 36 (0 UL)La grande région SaarLorLux, riche de ses travailleurs frontaliers Pigeron-Piroth, Isabelle ; E-print/Working paper (2016) Detailed reference viewed: 25 (2 UL)Fractional charge oscillations in quantum spin Hall quantum dots ; ; Dolcetto, Giacomo et al E-print/Working paper (2016) We show that correlated two-particle backscattering can induce fractional charge oscillations in a quantum dot built at the edge of a two-dimensional topological insulator by means of magnetic barriers ... [more ▼] We show that correlated two-particle backscattering can induce fractional charge oscillations in a quantum dot built at the edge of a two-dimensional topological insulator by means of magnetic barriers. The result nicely complements recent works where the fractional oscillations were obtained employing of semiclassical treatments. Moreover, since by rotating the magnetization of the barriers a fractional charge can be trapped in the dot via the Jackiw-Rebbi mechanism, the system we analyze offers the opportunity to study the interplay between this noninteracting charge fractionalization and the fractionalization due to two-particle backscattering. In this context, we demonstrate that the number of fractional oscillations of the charge density depends on the magnetization angle. Finally, we address the renormalization induced by two-particle backscattering on the spin density, which is characterized by a dominant oscillation, sensitive to the Jackiw-Rebbi charge, with a wavelength twice as large as the charge density oscillations. [less ▲] Detailed reference viewed: 12 (2 UL)Une minorité de citoyens reste nostalgique Paravantis, Spero E-print/Working paper (2016) Au cours de l’automne 1991, les républiques constituantes de l’Union soviétique proclamaient, l’une après l’autre, leur indépendance. Il y a 25 ans, avec la création de la Communauté des États ... [more ▼] Au cours de l’automne 1991, les républiques constituantes de l’Union soviétique proclamaient, l’une après l’autre, leur indépendance. Il y a 25 ans, avec la création de la Communauté des États indépendants (CEI), la superpuissance URSS a cessé d’exister d’un jour à l’autre. Dr. Spero S.Z. Paravantis de l’Université du Luxembourg revient sur ce grand chapitre de l’histoire. [less ▲] Detailed reference viewed: 25 (5 UL)The Gamma Stein equation and non-central de Jong theorems Döbler, Christian ; Peccati, Giovanni E-print/Working paper (2016) Detailed reference viewed: 27 (2 UL)Counting curves, and the stable length of currents ; Parlier, Hugo ; E-print/Working paper (2016) Let $\gamma_0$ be a curve on a surface $\Sigma$ of genus $g$ and with $r$ boundary components and let $\pi_1(\Sigma)\curvearrowright X$ be a discrete and cocompact action on some metric space. We study ... [more ▼] Let $\gamma_0$ be a curve on a surface $\Sigma$ of genus $g$ and with $r$ boundary components and let $\pi_1(\Sigma)\curvearrowright X$ be a discrete and cocompact action on some metric space. We study the asymptotic behavior of the number of curves $\gamma$ of type $\gamma_0$ with translation length at most $L$ on $X$. For example, as an application, we derive that for any finite generating set $S$ of $\pi_1(\Sigma)$ the limit $$\lim_{L\to\infty}\frac 1{L^{6g-6+2r}}\{\gamma\text{ of type }\gamma_0\text{ with }S\text{-translation length}\le L\}$$ exists and is positive. The main new technical tool is that the function which associates to each curve its stable length with respect to the action on $X$ extends to a (unique) continuous and homogenous function on the space of currents. We prove that this is indeed the case for any action of a torsion free hyperbolic group. [less ▲] Detailed reference viewed: 8 (0 UL)The multi-scale analysis of dynamic transmission volatility of carbon prices ; Terraza, Virginie E-print/Working paper (2016) The implementation of the EU ETS in 2005 led to the establishment of a price that enables manufacturers to realize the impact of their activities on the environment clean. There are no items in this day ... [more ▼] The implementation of the EU ETS in 2005 led to the establishment of a price that enables manufacturers to realize the impact of their activities on the environment clean. There are no items in this day, since the creation of the European carbon market, which has focused on the analysis of volatility transmission between different investment horizons. The purpose of this paper is to fill this gap in the literature. we analyze the volatility of the price of carbon quota (EUA), by studying linear and nonlinear causal relationships of wavelet components between the different volatilities that we captured at different time scales. we initially conducted the decomposition of the EUA price volatility at different time-frequency interval using a wavelet approach. Our study will be to examine whether the volatility is transmitted from the high-frequency structure of the carbon price in the low frequency. Our results show an intra-structural dependance in carbon price volatility. We detect instability in the volatility of carbon and observe the existence of a bidirectional relationship from high frequency traders to low frequency traders. Our study showed that high-frequency shocks yields carbon price can have a significant impact beyond their Fontiers and touch the low frequency structure associated with long-term traders [less ▲] Detailed reference viewed: 18 (2 UL)Inequality and Incentives: The Quasi-Natural Experiment of Hungary, 1914-2008 Mavridis, Dimitrios ; E-print/Working paper (2016) We construct the first top income share series of a formerly socialist economy before, during, and after socialism in order to exploit the effect of the quasi-natural experiment of the absence of markets ... [more ▼] We construct the first top income share series of a formerly socialist economy before, during, and after socialism in order to exploit the effect of the quasi-natural experiment of the absence of markets on incentives. We investigate top income shares dynamics and the sources of income at the upper tail of the income distribution. Within this setup, we study the effect of capital markets and liberalized wage settings on top income shares. Our estimates show that the introduction of wage-setting decentralization during socialism had a role in increasing the skill premium and income inequality in years prior the transition. [less ▲] Detailed reference viewed: 54 (10 UL)Enterprise credit, household credit and growth: New evidence from 126 countries Leon, Florian E-print/Working paper (2016) This paper attempts to distinguish the effects of household and enterprise credit on economic growth. To do so, I create a new, hand-collected database covering 143 countries over the period 1995-2014 ... [more ▼] This paper attempts to distinguish the effects of household and enterprise credit on economic growth. To do so, I create a new, hand-collected database covering 143 countries over the period 1995-2014 (126 countries are employed for econometric analysis). Estimation results confirm recent evidence documenting the absence of the effect of total credit to growth. Findings also show that household credit has a negative effect on growth, but I fail to provide robust support for a positive effect of business credit. [less ▲] Detailed reference viewed: 70 (9 UL)Arbeitszeitflexibilität in Luxemburg Sischka, Philipp ; Steffgen, Georges E-print/Working paper (2016) Männliche Arbeitnehmer weisen im Vergleich zu weiblichen Arbeitnehmern eine höhere Differenz zwischen vertraglich vereinbarter und faktischer Wochenarbeitszeit auf. Differenziert nach Berufsgruppen zeigt ... [more ▼] Männliche Arbeitnehmer weisen im Vergleich zu weiblichen Arbeitnehmern eine höhere Differenz zwischen vertraglich vereinbarter und faktischer Wochenarbeitszeit auf. Differenziert nach Berufsgruppen zeigt sich, dass inbesondere Manager sowie Führungskräfte deutlich mehr arbeiten, als vertraglich festgelegt. Atypische Arbeitszeiten (nach 19 Uhr, nach 22 Uhr oder am Wochenende) treten dagegen insbesondere bei jüngeren Arbeitnehmern (bis 44 Jahre) häufiger auf. Auch zeigen sich hier große Unterschiede über die Berufsgruppen hinweg. Für die Mehrheit der Arbeitnehmer entspricht die vertraglich vereinbarte Stundenzahl ihren Wünschen. Jedoch ist bei den jüngeren Arbeitnehmern der Anteil der Personen, die sich einen Vertrag mit mehr bezahlten Stunden wünschen deutlich höher. Differenziert nach Berufsgruppen äußern vor allem Hilfsarbeitskräfte sowie Arbeitnehmer in Dienstleistungs- und Handwerksberufen den Wunsch mehr bezahlte Stunden zu arbeiten. Die Arbeitszeitbedingungen der Arbeitnehmer weisen auch Zusammenhänge mit erlebten Work-Life-Konflikten, Zeitdruck, Stress und Arbeitszufriedenheit auf. Die Arbeitszeitbedingungen sind außerdem assoziiert mit nächtlichen Schlafstunden sowie mit der Gefährdung durch Burnout. Arbeitnehmer, die 46 Stunden und mehr arbeiten, die häufig atypische Arbeitszeiten haben, oder deren faktische Arbeitszeit stark von der vertraglich vereinbarten Arbeitszeit abweicht, erleben stärker Work-Life-Konflikte, Zeitdruck sowie Stress, geben jedoch eine geringere Arbeitszufriedenheit an, schlafen weniger und weisen eher Burnout auf. [less ▲] Detailed reference viewed: 19 (6 UL)Interrogating surface length spectra and quantifying isospectrality Parlier, Hugo E-print/Working paper (2016) This article is about inverse spectral problems for hyperbolic surfaces and in particular how length spectra relate to the geometry of the underlying surface. A quantitative answer is given to the ... [more ▼] This article is about inverse spectral problems for hyperbolic surfaces and in particular how length spectra relate to the geometry of the underlying surface. A quantitative answer is given to the following: how many questions do you need to ask a length spectrum to determine it completely? In answering this, a quantitative upper bound is given on the number of isospectral but non-isometric surfaces of a given genus. [less ▲] Detailed reference viewed: 10 (0 UL)Notes on a Lie algebraic relation Korvers, Stéphane E-print/Working paper (2016) We exhibit explicit orthogonal decompositions of every multidimensional restricted root space of a real semi-simple Lie algebra. We then show a link between this result and a radiality property of smooth ... [more ▼] We exhibit explicit orthogonal decompositions of every multidimensional restricted root space of a real semi-simple Lie algebra. We then show a link between this result and a radiality property of smooth functions on G-homogeneous spaces when G is a real semi-simple Lie group. [less ▲] Detailed reference viewed: 13 (0 UL)Beziehungen – Liens Relationnels. Realitäten, Perspektiven, Grenzen – réalités, perspectives et limites. Bericht zu einer Befragung von Mitarbeiterinnen und Jugendlichen bei Solidarité Jeunes 2016 Peters, Ulla ; Jäger, Julia E-print/Working paper (2016) Solidarité Jeunes asbl in Luxemburg hat eine Befragung zum Thema Beziehungen bei den Professionellen und Jugendlichen in ihren Einrichtungen durchgeführt. Sie beauftragten die Universität damit, die ... [more ▼] Solidarité Jeunes asbl in Luxemburg hat eine Befragung zum Thema Beziehungen bei den Professionellen und Jugendlichen in ihren Einrichtungen durchgeführt. Sie beauftragten die Universität damit, die Ergebnisse aufzubereiten, zu verschriftlichen und bei einer Fachtagung zum 40-jährigen Bestehen des Trägers (bis 2012 Jongenheem asbl) im September 2016 zu präsentieren. Der Fragebogen enthielt Fragen zu den Themen: was verstehen die Jugendlichen und die Professionellen unter einer guten Beziehung, wie gestalten sie diese, welche Rituale gibt es z. B. beim Abschied von Jugendlichen und wie wird dieser vorbereitet. Eine Frage war auch, ob und welche Art von Kontakte nach dem Verlassen der Einrichtung bestehen und für wichtig gehalten werden. Die Befragung basierte auf der Annahme und der Erfahrung, dass Beziehungen ein Schlüsselfaktor und Fundament jeder erfolgreichen pädagogischen Interven- tion sind und damit auch ein zentrales „Arbeitsmittel“. [less ▲] Detailed reference viewed: 62 (3 UL)Understanding unemployment scars: A vignette Experiment of employers' decisions in Bulgaria, Greece, Norway and Switzerland ; ; et al E-print/Working paper (2016) Detailed reference viewed: 32 (5 UL)Boosting Early Language as a Foundation for Literacy – Essential but neither Simple nor Easy ; Engel de Abreu, Pascale ; Ertel Silva, Cintia E-print/Working paper (2016) Detailed reference viewed: 49 (7 UL)Isogeometric finite element analysis of time-harmonic exterior acoustic scattering problems ; ; Bordas, Stéphane E-print/Working paper (2016) We present an isogeometric analysis of time-harmonic exterior acoustic problems. The infinite space is truncated by a fictitious boundary and (simple) absorbing boundary conditions are applied. The ... [more ▼] We present an isogeometric analysis of time-harmonic exterior acoustic problems. The infinite space is truncated by a fictitious boundary and (simple) absorbing boundary conditions are applied. The truncation error is included in the exact solution so that the reported error is an indicator of the performance of the isogeometric analysis, in particular of the related pollution error. Numerical results performed with high-order basis functions (third or fourth orders) showed no visible pollution error even for very high frequencies. This property combined with exact geometrical representation makes isogeometric analysis a very promising platform to solve high-frequency acoustic problems. [less ▲] Detailed reference viewed: 61 (11 UL)Geometric filling curves on surfaces ; Parlier, Hugo ; E-print/Working paper (2016) This note is about a type of quantitative density of closed geodesics on closed hyperbolic surfaces. The main results are upper bounds on the length of the shortest closed geodesic that $\varepsilon ... [more ▼] This note is about a type of quantitative density of closed geodesics on closed hyperbolic surfaces. The main results are upper bounds on the length of the shortest closed geodesic that $\varepsilon$-fills the surface. [less ▲] Detailed reference viewed: 17 (0 UL)Financial Constraint, Entrepreneurship and Sectoral Migrations Leon, Florian ; E-print/Working paper (2016) Using an original database of over 3,000 micro and small enterprises (MSEs) that were microfinance institution (MFI) clients in Madagascar over the period of 2008-2014, we observe that around one third of ... [more ▼] Using an original database of over 3,000 micro and small enterprises (MSEs) that were microfinance institution (MFI) clients in Madagascar over the period of 2008-2014, we observe that around one third of these entrepreneurs switched business sectors in the first five years after starting their business. We find that the probability of an entrepreneur’s changing sectors is highly correlated with the size of the first loan obtained from the MFI. This result survives multiple robustness checks, including treatment for endogeneity and attrition. We interpret this finding in terms of financial constraint: a lack of financing prevents an entrepreneur from initially investing in his first choice sector, causing him to change sectors only when he has become financially able to do so. This result challenges the classic distinction made between ”necessity entrepreneurs” and ”opportunity entrepreneurs” and raises important questions concerning entrepreneurial talent allocation. [less ▲] Detailed reference viewed: 77 (6 UL)Intertwining operators of the quantum Teichmüller space Mazzoli, Filippo E-print/Working paper (2016) Detailed reference viewed: 46 (8 UL)Constant Gauss curvature foliations of AdS spacetimes with particles Schlenker, Jean-Marc ; E-print/Working paper (2016) We prove that for any convex globally hyperbolic maximal (GHM) anti-de Sitter (AdS) 3-dimensional space-time N with particles (cone singularities of angles less than π along time-like curves), the ... [more ▼] We prove that for any convex globally hyperbolic maximal (GHM) anti-de Sitter (AdS) 3-dimensional space-time N with particles (cone singularities of angles less than π along time-like curves), the complement of the convex core in N admits a unique foliation by constant Gauss curvature surfaces. This extends, and provides a new proof of, a result of \cite{BBZ2}. We also describe a parametrization of the space of convex GHM AdS metrics on a given manifold, with particles of given angles, by the product of two copies of the Teichm\"uller space of hyperbolic metrics with cone singularities of fixed angles. Finally, we use the results on K-surfaces to extend to hyperbolic surfaces with cone singularities of angles less than π a number of results concerning landslides, which are smoother analogs of earthquakes sharing some of their key properties. [less ▲] Detailed reference viewed: 8 (0 UL)Short closed geodesics with self-intersections ; Parlier, Hugo E-print/Working paper (2016) Our main point of focus is the set of closed geodesics on hyperbolic surfaces. For any fixed integer $k$, we are interested in the set of all closed geodesics with at least $k$ (but possibly more) self ... [more ▼] Our main point of focus is the set of closed geodesics on hyperbolic surfaces. For any fixed integer $k$, we are interested in the set of all closed geodesics with at least $k$ (but possibly more) self-intersections. Among these, we consider those of minimal length and investigate their self-intersection numbers. We prove that their intersection numbers are upper bounded by a universal linear function in $k$ (which holds for any hyperbolic surface). Moreover, in the presence of cusps, we get bounds which imply that the self-intersection numbers behave asymptotically like $k$ for growing $k$. [less ▲] Detailed reference viewed: 11 (0 UL) |
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