Results for "Florian Trybel"

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Pressure induced Hydrogen-Hydrogen interaction in metallic FeH revealed by NMRFeb 08 2019Knowledge of the behavior of hydrogen in metal hydrides is the key for understanding their electronic properties. So far, no experimental methods exist to access these properties beyond 100 GPa, where high-Tc superconductivity emerges. Here, we present ... More
Representing Isabelle in LFSep 14 2010LF has been designed and successfully used as a meta-logical framework to represent and reason about object logics. Here we design a representation of the Isabelle logical framework in LF using the recently introduced module system for LF. The major novelty ... More
Beyond-MSSM Higgs sectorsSep 25 2014Oct 28 2014This is a compact overview of Higgs sectors in extensions of the MSSM. The focus is on the summary of the main features of models with additional singlets and triplets as well as of models with Dirac gauginos. In addition, also important aspects of models ... More
SARAH 3.2: Dirac Gauginos, UFO output, and moreJul 04 2012Feb 12 2013SARAH is a Mathematica package optimized for the fast, efficient and precise study of supersymmetric models beyond the MSSM: a new model can be defined in a short form and all vertices are derived. This allows SARAH to create model files for FeynArts/FormCalc, ... More
Challenge IEEE-ISBI/TCB : Application of Covariance matrices and wavelet marginalsOct 10 2014This short memo aims at explaining our approach for the challenge IEEE-ISBI on Bone Texture Characterization. In this work, we focus on the use of covariance matrices and wavelet marginals in an SVM classifier.
The Picard Group of Various Families of $(\mathbb{Z}/2\mathbb{Z})^{4}$-invariant Quartic K3 SurfacesNov 05 2015The subject of this paper is the study of various families of quartic K3 surfaces which are invariant under a certain $(\mathbb{Z}/2\mathbb{Z})^{4}$ action. In particular, we describe families whose general member contains $8,16,24$ or $32$ lines as well ... More
The Impact of Credit Risk and Implied Volatility on Stock ReturnsMay 30 2010This paper examines the possibility of using derivative-implied risk premia to explain stock returns. The rapid development of derivative markets has led to the possibility of trading various kinds of risks, such as credit and interest rate risk, separately ... More
Warped Extra Dimensions: Flavor, Precision Tests and Higgs PhysicsDec 29 2011In this thesis, the phenomenology of the Randall-Sundrum setup is investigated. In this context models with and without an enlarged SU(2)_L x SU(2)_R x U(1)_X x P_{LR} gauge symmetry, which removes corrections to the T parameter and to the Z b_L \bar ... More
Basic Orders for Defect Two Blocks of $\Z_p\Sym_n$Nov 30 2010We show how basic orders for defect two blocks of symmetric groups over the ring of $p$-adic integers can be constructed by purely combinatorial means.
Fuzzy Characterization of Near-Earth-AsteroidsMay 23 2009Due to close encounters with the inner planets, Near-Earth-Asteroids (NEAs) can have very chaotic orbits. Because of this chaoticity, a statistical treatment of the dynamical properties of NEAs becomes difficult or even impossible. We propose a new way ... More
The inverse problem for Schwinger pair productionSep 29 2015Dec 22 2015The production of electron-positron pairs in time-dependent electric fields (Schwinger mechanism) depends non-linearly on the applied field profile. Accordingly, the resulting momentum spectrum is extremely sensitive to small variations of the field parameters. ... More
Iteratively reweighted adaptive lasso for conditional heteroscedastic time series with applications to AR-ARCH type processesFeb 23 2015Dec 05 2015Shrinkage algorithms are of great importance in almost every area of statistics due to the increasing impact of big data. Especially time series analysis benefits from efficient and rapid estimation techniques such as the lasso. However, currently lasso ... More
Non-conservative Lagrangian method for half-dark solitons in spinor non-equilibrium Polariton condensatesJan 08 2015In this work I introduce a powerful analytical method to analyze states of non-equilibrium polariton Bose-Einstein condensates (BEC). It is shown that the condensate wave functions carrying dark solitons and half-dark solitons can be expressed in terms ... More
Gaussian impurity moving through a Bose-Einstein superfluidOct 13 2016Oct 21 2016In this paper a Gaussian impurity moving through an equilibrium Bose-Einstein condensate at T = 0 is studied. The problem can be described by a Gross-Pitaevskii equation, which is solved perturbatively. The analysis is done for systems of 2 and 3 spatial ... More
Confinement for Active ObjectsMay 05 2014In this paper, we provide a formal framework for the security of distributed active objects. Active objects communicate asynchronously implementing method calls via futures. We base the formal framework on a security model that uses a semi-lattice to ... More
The CMS Particle Flow AlgorithmJan 31 2014A particle flow event-reconstruction algorithm has been successfully deployed in the CMS experiment and is nowadays used by most of the analyses. It aims at identifying and reconstructing individually each particle arising from the LHC proton-proton collision, ... More
Bose-Einstein Condensates with Derivative and Long-Range Interactions as Set-Ups for Analog Black HolesDec 10 2013Sep 30 2014General types of Bose-Einstein condensates are considered. The formation of black-hole analogues is examined for both short- and long-range interactions for arbitrary spatial dimensions greater than two. The former case includes non-linear derivative ... More
Cycle modules and the intersection A-infinity algebraJun 27 2009Given a cycle module M with a ring structure we show that the cycle complex with coefficients in M of a smooth scheme of finite type over a field has a A-infinity algebra structure. In the case of Milnor K-theory this gives a homotopy model for the classical ... More
Reverse mathematics of the finite downwards closed subsets of $\mathbb{N}^k$ ordered by inclusionOct 04 2016Nov 15 2016We show that the well-partial orderedness of the finite downwards closed subsets of $\mathbb{N}^k$ ,ordered by inclusion, is equivalent to the well-foundedness of the ordinal $\omega^{\omega^\omega}$. This was conjectured to be the case by Hatzikiriakou ... More
The integral polytope groupMay 04 2016Apr 25 2017We show that the Grothendieck group associated to integral polytopes in $\mathbb{R}^n$ is free-abelian by providing an explicit basis. Moreover, we identify the involution on this polytope group given by reflection about the origin as a sum of Euler characteristic ... More
Complexity theory for spaces of integrable functionsDec 19 2016Sep 09 2017This paper investigates second-order representations in the sense of Kawamura and Cook for spaces of integrable functions that regularly show up in analysis. It builds upon prior work about the space of continuous functions on the unit interval: Kawamura ... More
The Iwasawa Main Conjecture for elliptic curves at odd supersingular primesOct 31 2016In this paper, we prove the Iwasawa main conjecture for elliptic curves at an odd supersingular prime p. Some consequences are the p-parts of the leading term formulas in the Birch and Swinnerton-Dyer conjectures for analytic rank 0 or 1.
Alternation Is Strict For Higher-Order Modal Fixpoint LogicSep 14 2016We study the expressive power of Alternating Parity Krivine Automata (APKA), which provide operational semantics to Higher-Order Modal Fixpoint Logic (HFL). APKA consist of ordinary parity automata extended by a variation of the Krivine Abstract Machine. ... More
Global deformations of certain rational almost homogeneous projective bundlesJul 26 2016We study global deformations of certain projective bundles over projective spaces. We show that any projective global deformation of a projective bundle over $\bP^1$ carries the structure of a projective bundle over some projective space. Furthermore, ... More
A formulation for p-adic versions of the Birch and Swinnerton-Dyer conjectures in the supersingular caseDec 31 2015Given an elliptic curve E and a prime p of (good) supersingular reduction, we formulate p-adic analogues of the Birch and Swinnerton-Dyer conjecture using a pair of Iwasawa functions L^\sharp(E,T) and L^\flat(E,T). They are equivalent to the conjectures ... More
The Shafarevich-Tate group in cyclotomic Z_p-extensions at supersingular primesJun 10 2011We study the asymptotic growth of the p-primary component of the Shafarevich-Tate group in the cyclotomic direction at any odd prime of good supersingular reduction, generalizing work of Kobayashi. This explains formulas obtained by Kurihara, Perrin-Riou, ... More
The $L^2$-torsion polytope of amenable groupsApr 24 2017Jan 29 2018We introduce the notion of groups of polytope class and show that torsion-free amenable groups satisfying the Atiyah Conjecture possess this property. A direct consequence is the homotopy invariance of the $L^2$-torsion polytope among $G$-CW-complexes ... More
Filtering out the cosmological constant in the Palatini formalism of modified gravityJul 15 2010Jan 20 2011According to theoretical physics the cosmological constant (CC) is expected to be much larger in magnitude than other energy densities in the universe, which is in stark contrast to the observed Big Bang evolution. We address this old CC problem not by ... More
Gravity and Quantum Fields in Discrete Space-TimesOct 27 2006In a 6D model, where the extra dimensions form a discretised curved disk, we investigate the mass spectra and profiles of gravitons and Dirac fermions. The discretisation is performed in detail leading to a star-like geometry. In addition, we use the ... More
Uniformly distributed sequences in the orthogonal group and on the Grassmannian manifoldMay 16 2014Sep 17 2014Quasi-Monte Carlo methods replaced classical Monte Carlo methods in many areas of numerical analysis over the last decades. The purpose of this paper is to extend quasi-Monte Carlo methods into a new direction. We construct and implement a uniformly distributed ... More
Counting Algebraic Curves with Tropical GeometryJun 09 2012Tropical geometry is a piecewise linear "shadow" of algebraic geometry. It allows for the computation of several cohomological invariants of an algebraic variety. In particular, its application to enumerative algebraic geometry led to significant progress. ... More
Computing Node Polynomials for Plane CurvesJun 01 2010Mar 09 2011According to the G\"ottsche conjecture (now a theorem), the degree N^{d, delta} of the Severi variety of plane curves of degree d with delta nodes is given by a polynomial in d, provided d is large enough. These "node polynomials" N_delta(d) were determined ... More
Reverse mathematics of the finite downwards closed subsets of $\mathbb{N}^k$ ordered by inclusion and adjacent Ramsey for fixed dimensionOct 04 2016Oct 04 2017We show that the well-partial orderedness of the finite downwards closed subsets of $\mathbb{N}^k$ ,ordered by inclusion, is equivalent to the well-foundedness of the ordinal $\omega^{\omega^\omega}$. This was conjectured to be the case by Hatzikiriakou ... More
The weight in a Serre-type conjecture for tame n-dimensional Galois representationsMar 03 2008Jul 04 2011We formulate a Serre-type conjecture for n-dimensional Galois representations that are tamely ramified at p. The weights are predicted using a representation-theoretic recipe. For n = 3 some of these weights were not predicted by the previous conjecture ... More
Brownian Motions on Metric Graphs with Non-Local Boundary Conditions I: CharacterizationMay 17 2018A classification for Brownian motions on metric graphs, that is, right continuous strong Markov processes which behave like a one-dimensional Brownian motion on the edges and feature effects like Walsh skewness, stickiness and jumps at the vertices, is ... More
Cops, robbers, and infinite graphsOct 30 2014Mar 30 2015Cops and robbers is a game between two players, where one tries to catch the other by moving along the edges of a graph. It is well known that on a finite graph the cop has a winning strategy if and only if the graph is constructible and that finiteness ... More
Model-Independent Pricing of Asian Options via Optimal Martingale TransportDec 03 2014In this article we discuss the problem of calculating optimal model-independent (robust) bounds for the price of Asian options with discrete and continuous averaging. We will give geometric characterisations of the maximising and the minimising pricing ... More
When is an origami set a ring?Apr 27 2018Starting with a flat sheet of paper, points can be constructed as the intersection of two folds. The set of constructible points clearly depends on which folds are admissible. In this paper, we study the situation where a fold is admissible if its slope ... More
Symmetries, psudosymmetries and conservation laws in Lagrangian and Hamiltonian $k$-symplectic formalismsOct 16 2014In this paper we will present Lagrangian and Hamiltonian $k$-symplectic formalisms, we will recall the notions of symmetry and conservation law and we will define the notion of pseudosymmetry as a natural extension of symmetry. Using symmetries and pseudosymmetries, ... More
On $α$-largeness and the Paris-Harrington principle in $\mathrm{RCA}_0$ and $\mathrm{RCA}_0^{\displaystyle{*}}$Nov 28 2016Jul 14 2018We examine, within $\mathrm{RCA}_0$, the treatment by Ketonen and Solovay on the use of $\alpha$-largeness for giving an upper bound for the Paris--Harrington principle. This proof works fine in $\mathrm{RCA}_0^{\displaystyle{*}}$ for every fixed standard ... More
On "finitary" Ramsey's theoremAug 09 2015Nov 29 2016We examine a version of Ramsey's theorem based on Tao, Gaspar and Kohlenbach's "finitary" infinite pigeonhole principle.We will show that the "finitary" infinite Ramsey's theorem naturally gives rise to statements at the level of the infinite Ramsey's ... More
Monoide des enlacements et facteurs orthogonaux (Monoids of linking pairings and orthogonal summands)Mar 14 2005Jun 17 2005A linking pairing is a symetric bilinear pairing lambda: GxG --> Q/Z on a finite abelian group. The set of isomorphism classes of linking pairings is a non-cancellative monoid E under orthogonal sum, which is infinitely generated and infinitely related. ... More
Torsion bounds for elliptic curves and Drinfeld modulesOct 17 2008We derive asymptotically optimal upper bounds on the number of L-rational torsion points on a given elliptic curve or Drinfeld module defined over a finitely generated field K, as a function of the degree [L:K]. Our main tool is the adelic openness of ... More
Intersection patterns of finite sets and of convex setsJul 04 2016The main result is a common generalization of results on lower bounds for the chromatic number of r-uniform hypergraphs and some of the major theorems in Tverberg-type theory, which is concerned with the intersection pattern of faces in a simplicial complex ... More
Phase transition results for three Ramsey-like theoremsMar 22 2016We classify a sharp phase transition threshold for Friedman's finite adjacent Ramsey theorem. We extend the method for showing this result to two previously known classifications involving Ramsey theorem variants: the Paris--Harrington theorem and the ... More
Lifting of morphisms to quotient presentationsSep 30 2002In this article we investigate algebraic morphisms between toric varieties. Given presentations of toric varieties as quotients we are interested in the question when a morphism admits a lifting to these quotient presentations. We show that this can be ... More
Lévy processes with values in locally convex Suslin spacesOct 02 2015We provide a L\'evy-It\^o decomposition of sample paths of L\'evy processes with values in complete locally convex Suslin spaces. This class of state spaces contains the well investigated examples of separable Banach spaces, as well as Fr\'echet or distribution ... More
Generalized orthogonal matching pursuit for multiple measurements - A structural approachMay 23 2017Sparse data approximation has become a popular research topic in signal processing. However, in most cases only a single measurement vector (SMV) is considered. In applications, the multiple measurement vector (MMV) case is more usual, i.e., the sparse ... More
Integral points of bounded height on a log Fano threefoldJan 24 2019We determine an asymptotic formula for the number of integral points of bounded height on a blow-up of $\mathbb{P}^3$ outside certain planes using universal torsors.
Recursion Relations for Long-Range Integrable Spin Chains with Open Boundary ConditionsJan 04 2012Apr 26 2012It is well known that integrable charges for short-range (e.g. nearest-neighbor) spin chains with periodic boundary conditions can be recursively generated by a so-called boost operator. In the past, this iterative construction has been generalized to ... More
On the Structure of Monodromy Algebras and Drinfeld DoublesSep 18 1996Oct 11 1996We give a review and some new relations on the structure of the monodromy algebra (also called loop algebra) associated with a quasitriangular Hopf algebra H. It is shown that as an algebra it coincides with the so-called braided group constructed by ... More
Local cohomology and F-stabilityApr 28 2009Jun 25 2009We study the relationship between the Frobenius stability of an Artinian module over an F-injective ring and its stable part.
Standard Model statistics of a Type II orientifoldDec 15 2005Dec 22 2005We analyse four-dimensional, supersymmetric intersecting D-brane models in a toroidal orientifold background from a statistical perspective. The distribution and correlation of observables, like gauge groups and couplings, are discussed. We focus on models ... More
Statistics in the Landscape of Intersecting Brane ModelsOct 12 2007Mar 24 2008An approach towards a statistical survey of four dimensional supersymmetric vacua in the string theory landscape is described and illustrated with three examples of ensembles of intersecting D-brane models. The question whether it is conceivable to make ... More
On not testing the foreign-language effect: A comment on Costa, Foucart, Arnon, Aparici, and Apesteguia (2014)Jun 25 2015In their first five studies, Costa, Foucart, Arnon, Aparici, and Apesteguia (2014) fail to provide a statistical test of the foreign-language effect. Instead, the authors employ a procedure in which they test the framing effects separately for the native ... More
Blocks with a generalized quaternion defect group and three simple modules over a 2-adic ringJun 16 2015We show that two blocks of generalized quaternion defect with three simple modules over a sufficiently large $2$-adic ring $\mathcal O$ are Morita-equivalent if and only if the corresponding blocks over the residue field of $\mathcal O$ are Morita-equivalent. ... More
Superfluidity in driven non-equilibrium Bose-Einstein condensates due to balanced forcesNov 10 2016In this letter an analytical proof of the existence and suppression of superfluidity in open Bose- Einstein condensates (BEC) such as those of Exciton-Polaritons (Polaritons) or the atom laser is given. To test superfluidity in the mean-field regime of ... More
Automatic Calculation of supersymmetric Renormalization Group Equations and Self EnergiesFeb 03 2010Jan 11 2011SARAH is a Mathematica package for studying supersymmetric models. It calculates for a given model the masses, tadpole equations and all vertices at tree-level. Those information can be used by \SARAH to write model files for CalcHep/CompHep or FeynArts/FormCalc. ... More
Automation of non-SUSY two-loop RGEs with PyR@TE: latest developmentsOct 29 2015In light of the conspicuous absence of SUSY in the energy range explored by the LHC during run I, non-supersymmetric BSM scenarios are becoming more and more attractive. One key ingredient in exploring such BSM physics are the renormalization group equations ... More
On the impact of kinetic mixing in beta functions at two-loopAug 25 2016Sep 06 2016Kinetic mixing is a fundamental property of models with a gauge symmetry involving several $\mathrm{U}(1)$ group factors. In this paper, we perform a numerical study of the impact of kinetic mixing on beta functions at two-loop. To do so, we use the recently ... More
Lectures on Yangian SymmetryJun 09 2016Jul 26 2016In these introductory lectures we discuss the topic of Yangian symmetry from various perspectives. Forming the classical counterpart of the Yangian and an extension of ordinary Noether symmetries, first the concept of nonlocal charges in classical, two-dimensional ... More
A closer look at non-decoupling D-TermsMar 18 2016May 09 2016Non-Decoupling D-Terms are an attractive possibility to enhance the tree-level mass of the standard model like Higgs boson in supersymmetric models. We discuss here for the case of a new Abelian gauge group two effects usually neglected in literature: ... More
Analytical calculation of the axis angle 2V from extinction measurements on the spindle stageFeb 27 2017A concise derivation of the "Joel equations", which allow for the determination of the axis angle 2V from measurements of extinction directions on a spindle stage, is provided starting from the wave-equation. Only analytic methods and no geometric arguments ... More
Lower bounds on the size of general Schrödinger-cat states from experimental dataOct 11 2016Mar 20 2017Experimental progress with meso- and macroscopic quantum states (i.e., general Schrodinger-cat states) was recently accompanied by theoretical proposals on how to measure the merit of these efforts. So far, experiment and theory were disconnected as theoretical ... More
Instantaneous non-local computation of low T-depth quantum circuitsNov 09 2015Sep 26 2016Instantaneous non-local quantum computation requires multiple parties to jointly perform a quantum operation, using pre-shared entanglement and a single round of simultaneous communication. We study this task for its close connection to position-based ... More
Beyond superfluidity in driven non-equilibrium Bose-Einstein condensatesNov 10 2016Apr 04 2017The phenomenon of superfluidity in open Bose-Einstein condensates (BEC) is analysed numerically and analytically. It is found that a superfluid phase is feasible even above the speed of sound, when forces due to inhomogeneous non-equilibrium processes ... More
Levine's motivic comparison theorem revisitedJan 22 2007For a field of characteristic zero, M. Levine has proved that his category of triangulated motives is equivalent to the one constructed by V. Voevodsky. In this paper we show that the strategy of Levine's proof can be applied on every perfect field to ... More
Elementary equivalence versus IsomorphismSep 20 2001How does the first order language of fields encode birational invariants of varieties?... This question is related to rational points on varieties and effectiveness in algebraic/arithmetic geometry.
Dealing with cross-country heterogeneity in panel VARs using finite mixture modelsApr 04 2018In this paper, we provide a parsimonious means to estimate panel VARs with stochastic volatility. We assume that coefficients associated with domestic lagged endogenous variables arise from a Gaussian mixture model. Shrinkage on the cluster size is introduced ... More
Vector Field Twisting of Lie-AlgebrasJul 11 2006Aug 10 2006In quantum groups coproducts of Lie-algebras are twisted in terms of generators of the corresponding universal enveloping algebra. If representations are considered, twists also serve as starproducts that accordingly quantize representation spaces. In ... More
The Cosmological Constant and Discrete Space-TimesOct 16 2006In this thesis the cosmological constant is investigated from two points of view. First, we study the influence of a time-dependent cosmological constant on the late-time expansion of the universe. Thereby, we consider several combinations of scaling ... More
Perturbations in the relaxation mechanism for a large cosmological constantSep 11 2009Jan 12 2010Recently, a mechanism for relaxing a large cosmological constant (CC) has been proposed [arxiv:0902.2215], which permits solutions with low Hubble rates at late times without fine-tuning. The setup is implemented in the LXCDM framework, and we found a ... More
Bounds for the annealed return probability on large finite percolation clustersNov 30 2008Aug 26 2012Bounds for the expected return probability of the delayed random walk on finite clusters of an invariant percolation on transitive unimodular graphs are derived. They are particularly suited for the case of critical Bernoulli percolation and the associated ... More
Improved Delsarte bounds for spherical codes in small dimensionsJan 27 2005Mar 10 2008We present an extension of the Delsarte linear programming method. For several dimensions it yields improved upper bounds for kissing numbers and for spherical codes. Musin's recent work on kissing numbers in dimensions three and four can be viewed in ... More
Invariance of the BFV-complexDec 12 2008Nov 21 2010The BFV-formalism was introduced to handle classical systems, equipped with symmetries. It associates a differential graded Poisson algebra to any coisotropic submanifold $S$ of a Poisson manifold $(M,\Pi)$. However the assignment (coisotropic submanifold) ... More
A Probabilistic Look at Conservative Growth-Fragmentation EquationsSep 08 2016Nov 02 2016In this note, we consider general growth-fragmentation equations from a probabilistic point of view. Using Foster-Lyapunov techniques, we study the recurrence of the associated Markov process depending on the growth and fragmentation rates. We prove the ... More
Special subvarieties of Drinfeld modular varietiesMar 22 2005Feb 28 2009We explore an analogue of the Andr\'e-Oort conjecture for subvarieties of Drinfeld modular varieties. The conjecture states that a subvariety $X$ of a Drinfeld modular variety contains a Zariski-dense set of complex multiplication (CM) points if and only ... More
The Galois action on M-Origamis and their Teichmüller curvesAug 28 2014We consider a rather special class of translation surfaces (called M-Origamis in this work) that are obtained from dessins by a construction introduced by Martin M\"oller. We give a new proof with a more combinatorial flavour of M\"oller's theorem that ... More
Update of the flavour-physics constraints in the NMSSMDec 07 2015We consider the impact of several flavour-changing observables in the $B$- and the Kaon sectors on the parameter space of the NMSSM, in a minimal flavour violating version of this model. Our purpose consists in updating our previous results in arXiv:0710.3714 ... More
Topological Entropy of Formal LanguagesJan 22 2018In this thesis we will introduce topological automata and the topological entropy of a topological automaton, which is the topological entropy of the dynamical system contained in the automaton. We will use these notions to define a measure of complexity ... More
Ranking Functions for Vector Addition SystemsOct 23 2017Vector addition systems are an important model in theoretical computer science and have been used for the analysis of systems in a variety of areas. Termination is a crucial property of vector addition systems and has received considerable interest in ... More
The shortest way to visit all metro lines in a citySep 13 2017Apr 10 2018What if $\{$a tourist, a train addict, Dr. Sheldon Cooper, somebody who likes to waste time$\}$ wants to visit all metro lines or carriages in a given network in a minimum number of steps? We study this problem with an application to the metro network ... More
Index Search Algorithms for Databases and Modern CPUsJun 20 2017Over the years, many different indexing techniques and search algorithms have been proposed, including CSS-trees, CSB+ trees, k-ary binary search, and fast architecture sensitive tree search. There have also been papers on how best to set the many different ... More
xSLHA: an Les Houches Accord reader for Python and MathematicaDec 11 2018The format defined by the SUSY Les Houches Accord (SLHA) is widely used in high energy physics to store and exchange information. It is no longer applied only to a few supersymmetric models, but the general structure is adapted to all kind of models. ... More
Refined enumerations of alternating sign trianglesApr 27 2018This article introduces and investigates a refinement of alternating sign trapezoids by means of Catalan objects and Motzkin paths. Alternating sign trapezoids are a generalisation of alternating sign triangles that were recently introduced by Ayyer, ... More
The super-critical contact process has a spectral gapOct 23 2013We consider the super-critical contact process on $\mathbb{Z}^d$. It is known that measures which dominate the upper invariant measure $\mu$ converge exponentially fast to $\mu$. However, the same is not true for measures which are below $\mu$, as the ... More
Sharp estimates of the Kobayashi metric and Gromov hyperbolicityJan 03 2008Let D be a smooth relatively compact and strictly J-pseudoconvex domain in a four dimensional almost complex manifold (M,J). We give sharp estimates of the Kobayashi metric. Our approach is based on an asymptotic quantitative description of both the domain ... More
The Picard Group of Various Families of $(\mathbb{Z}/2\mathbb{Z})^{4}$-invariant Quartic K3 SurfacesNov 05 2015Jul 18 2017The subject of this paper is the study of various families of quartic K3 surfaces which are invariant under a certain $(\mathbb{Z}/2\mathbb{Z})^{4}$ action. In particular, we describe families whose general member contains $8,16,24$ or $32$ lines as well ... More
On the Monodromy and Galois Group of Conics Lying on Heisenberg Invariant Quartic K3 SurfacesNov 04 2015In "Curves on Heisenberg invariant quartic surfaces in projective 3-space", Eklund showed that a general $(\mathbb{Z}/2\mathbb{Z})^{4}$-invariant quartic K3 surface contains at least $320$ conics. In this paper we analyse the field of definition of those ... More
A projector based convergence proof of the Ginelli algorithm for covariant Lyapunov vectorsFeb 23 2018Linear perturbations of solutions of dynamical systems exhibit different asymptotic growth rates, which are naturally characterized by so-called covariant Lyapunov vectors (CLVs). Due to an increased interest of CLVs in applications, several algorithms ... More
On the 2-Abelian Complexity of the Thue-Morse WordApr 15 2014Jun 02 2015We show that the 2-abelian complexity of the infinite Thue-Morse word is 2-regular, and other properties of the 2-abelian complexity, most notably that it is a concatenation of palindromes of increasing length. We also show sharp bounds for the length ... More
Chromatic numbers of stable Kneser hypergraphs via topological Tverberg-type theoremsOct 25 2017Kneser's 1955 conjecture -- proven by Lov\'asz in 1978 -- asserts that in any partition of the $k$-subsets of $\{1, 2, \dots, n\}$ into $n-2k-3$ parts, one part contains two disjoint sets. Schrijver showed that one can restrict to significantly fewer ... More
Random colorings and automorphism breaking in locally finite graphsApr 24 2013A colouring of a graph G is called distinguishing if its stabiliser in Aut G is trivial. It has been conjectured that, if every automorphism of a locally finite graph moves infinitely many vertices, then there is a distinguishing 2-colouring. We study ... More
Optimal regularity for two-dimensional Pfaffian systems and the fundamental theorem of surface theoryApr 16 2019We prove that a Pfaffian system with coefficients in the critical space $L^2_\mathrm{loc}$ on a simply connected open subset of $\mathbb{R}^2$ has a non-trivial solution in $W^{1,2}_\mathrm{loc}$ if the coefficients are antisymmetric and satisfy a compatibility ... More
The MMT API: A Generic MKM SystemJun 13 2013The MMT language has been developed as a scalable representation and interchange language for formal mathematical knowledge. It permits natural representations of the syntax and semantics of virtually all declarative languages while making MMT-based MKM ... More
A Framework for an Ego-centered and Time-aware Visualization of Relations in Arbitrary Data RepositoriesSep 27 2010Understanding constellations in large data collections has become a common task. One obstacle a user has to overcome is the internal complexity of these repositories. For example, extracting connected data from a normalized relational database requires ... More
p-Adic Lifting Problems and Derived EquivalencesFeb 08 2011Jan 08 2012For two derived equivalent $k$-algebras $\bar\Lambda$ and $\bar\Gamma$, we introduce a correspondence between $\OO$-orders reducing to $\bar\Lambda$ and $\OO$-orders reducing to $\bar\Gamma$. We outline how this may be used to transfer properties like ... More
Reverse mathematics of the finite downwards closed subsets of $\mathbb{N}^k$ ordered by inclusionOct 04 2016Oct 05 2016We show that the well-partial orderedness of the finite downwards closed subsets of $\mathbb{N}^k$ ,ordered by inclusion, is equivalent to the well-foundedness of the ordinal $\omega^{\omega^\omega}$. This was conjectured to be the case by Hatzikiriakou ... More
Vortex formation and dynamics in two-dimensional driven-dissipative condensatesJul 23 2016We investigate the real-time evolution of lattice bosons in two spatial dimensions whose dynamics is governed by a Markovian quantum master equation. We derive the generalization of the truncated Wigner approximation for open quantum many-body systems ... More
The Distribution of Optimal Strategies in Symmetric Zero-sum GamesNov 18 2016Given a skew-symmetric matrix, the corresponding two-player symmetric zero-sum game is defined as follows: one player, the row player, chooses a row and the other player, the column player, chooses a column. The payoff of the row player is given by the ... More