Results for "Marc Heinrich"

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A polynomial version of Cereceda's conjectureMar 13 2019Let $k$ and $d$ be such that $k \ge d+2$. Consider two $k$-colourings of a $d$-degenerate graph $G$. Can we transform one into the other by recolouring one vertex at each step while maintaining a proper coloring at any step? Cereceda et al. answered that ... More
A generalization of Arc-KaylesSep 15 2017Oct 05 2018The game Arc-Kayles is played on an undirected graph with two players taking turns deleting an edge and its endpoints from the graph. We study a generalization of this game, Weighted Arc Kayles (WAK for short), played on graphs with counters on the vertices. ... More
Evolving Design Rules for the Inverse Granular Packing ProblemMar 17 2014If a collection of identical particles is poured into a container, different shapes will fill to different densities. But what is the shape that fills a container as close as possible to a pre-specified, desired density? We demonstrate a solution to this ... More
Local Conflict ColoringNov 04 2015Locally finding a solution to symmetry-breaking tasks such as vertex-coloring, edge-coloring, maximal matching, maximal independent set, etc., is a long-standing challenge in distributed network computing. More recently, it has also become a challenge ... More
Asymptotically exact streaming algorithmsAug 08 2014We introduce a new computational model for data streams: asymptotically exact streaming algorithms. These algorithms have an approximation ratio that tends to one as the length of the stream goes to infinity while the memory used by the algorithm is restricted ... More
The Glauber dynamics for edges colourings of treesDec 13 2018Let $T$ be a tree on $n$ vertices and with maximum degree $\Delta$. We show that for $k\geq \Delta+1$ the Glauber dynamics for $k$-edge-colourings of $T$ mixes in polynomial time in $n$. The bound on the number of colours is best possible as the chain ... More
A probabilistic Hadwiger-Nelson problemJan 11 2015If you color a table using k colors, and throw a needle randomly on it, for some proper definition, you get a certain probability that the endpoints will fall on different colors. How can one make this probability maximal? This problem is related to finite ... More
Stochastic domination for the last passage percolation modelJul 18 2008Nov 16 2009A competition model on $\mathbb{Z}_+^{2}$ governed by directed last passage percolation is considered. A stochastic domination argument between subtrees of the last passage percolation is put forward.
Cycle Decompositions and Constructive CharacterizationsAug 30 2017Jan 07 2019Decomposing an Eulerian graph into a minimum respectively maximum number of edge disjoint cycles is an NP-complete problem. We prove that an Eulerian graph decomposes into a unique number of cycles if and only if it does not contain two edge disjoint ... More
Euler Coefficients and Restricted Dyck PathsMay 21 2007We consider the problem of enumerating Dyck paths staying weakly above the x-axis with a limit to the number of consecutive up steps, or a limit to the number of consecutive down steps. We use Finite Operator Calculus to obtain formulas for the number ... More
Random modification effect in the size of the fluctuation of the LCS of two sequences of i.i.d. blocksNov 11 2010Nov 12 2010The problem of the order of the fluctuation of the Longest Common Subsequence (LCS) of two independent sequences has been open for decades. There exist contradicting conjectures on the topic, due to Chvatal - Sankoff in 1975 and Waterman in 1994. In the ... More
Properties of minimally doubled fermionsJun 21 2017Most quark actions in lattice QCD encounter difficulties with chiral symmetry and its spontaneous breakdown. Minimally doubled fermions (MDF) are a category of strictly local chiral lattice fermions, whose continuum limit reproduces two degenerate quark ... More
On spectral distribution of high dimensional covariation matricesOct 24 2014In this paper we present the asymptotic theory for spectral distributions of high dimensional covariation matrices of Brownian diffusions. More specifically, we consider $N$-dimensional Ito integrals with time varying matrix-valued integrands. We observe ... More
Discriminating sterile neutrinos and unitarity violation with CP invariantsNov 25 2016Dec 20 2016We present a new method to analyze upcoming results in the search for CP violating neutrino oscillations. The CP violating amplitudes $\mathcal{A}_{\alpha\beta}^{kj}$ provide parametrization independent observables, which will be accessible by experiments ... More
Operational Discrete Symmetries and CP-ViolationMar 18 1996The discrete symmetries of the Lorentz group are on the one hand a `complex' interplay between linear and anti-linear operations on spinor fields and on the other hand simple linear reflections of the Minkowski space. We define operations for T, CP and ... More
Correlation functions with Karsten-Wilczek fermionsJan 25 2016The Karsten-Wilczek action describes two chiral fermions but breaks the symmetries under both charge conjugation ($ \widehat{C}) $ and time reflection ($ \widehat{\Theta} $) explicitly, though invariance under $ \widehat{C\Theta} $ and a mirror fermion ... More
A Qualitative Post-Experience Method for Evaluating Changes in VR Presence Experience Over TimeMay 14 2019A particular measure to evaluate a head-mounted display (HMD) based experience is the state of feeling present in virtual reality. Interruptions of a presence experience - break in presence (BIP) - appearing over time, need to be detected to assess and ... More
Towards Logical Architecture and Formal Analysis of Dependencies Between ServicesDec 11 2014This paper presents a formal approach to modelling and analysis of data and control flow dependencies between services within remotely deployed distributed systems of services. Our work aims at elaborating for a concrete system, which parts of the system ... More
Enumerating minimal dominating sets in triangle-free graphsOct 01 2018It is a long-standing open problem whether the minimal dominating sets of a graph can be enumerated in output-polynomial time. In this paper we prove that this is the case in triangle-free graphs. This answers a question of Kant\'e et al. Additionally, ... More
The switch operators and push-the-button games: a sequential compound over rulesetsJul 25 2017Dec 21 2017We study operators that combine combinatorial games. This field was initiated by Sprague-Grundy (1930s), Milnor (1950s) and Berlekamp-Conway-Guy (1970-80s) via the now classical disjunctive sum operator on (abstract) games. The new class consists in operators ... More
On the Cartesian Skeleton and the Factorization of the Strong Product of DigraphsJan 20 2014The three standard products (the Cartesian, the direct and the strong product) of undirected graphs have been wellinvestigated, unique prime factor decomposition (PFD) are known and polynomial time algorithms have been established for determining the ... More
The Perfect Matching Reconfiguration ProblemApr 12 2019We study the perfect matching reconfiguration problem: Given two perfect matchings of a graph, is there a sequence of flip operations that transforms one into the other? Here, a flip operation exchanges the edges in an alternating cycle of length four. ... More
Hajós' cycle conjecture for small graphsMay 24 2017Haj\'os' conjecture states that an Eulerian graph of order n can be decomposed into at most (n-1)/2 edge-disjoint cycles. We describe preprocessing steps, heuristics and integer programming techniques that enable us to verify Haj\'os' conjecture for all ... More
Turning Statistical Physics Models Into Materials Design EnginesOct 19 2015Despite the success statistical physics has enjoyed at predicting the properties of materials for given parameters, the inverse problem, identifying which material parameters produce given, desired properties, is only beginning to be addressed. Recently, ... More
Multi-Domain Adversarial LearningMar 21 2019Multi-domain learning (MDL) aims at obtaining a model with minimal average risk across multiple domains. Our empirical motivation is automated microscopy data, where cultured cells are imaged after being exposed to known and unknown chemical perturbations, ... More
Enumerating minimal dominating sets in $K_t$-free graphs and variantsOct 01 2018Mar 04 2019It is a long-standing open problem whether the minimal dominating sets of a graph can be enumerated in output-polynomial time. In this paper we investigate this problem in graph classes defined by forbidding an induced subgraph. In particular, we provide ... More
Limit theorems for functionals on the facets of stationary random tessellationsSep 05 2007We observe stationary random tessellations $X=\{\Xi_n\}_{n\ge1}$ in $\mathbb{R}^d$ through a convex sampling window $W$ that expands unboundedly and we determine the total $(k-1)$-volume of those $(k-1)$-dimensional manifold processes which are induced ... More
Numerical studies of Minimally Doubled FermionsDec 02 2013Dec 03 2013We have performed the first numerical study of minimally doubled fermions of the Karsten-Wilczek class in the quenched approximation. This requires fixing the counterterms, which arise due to hypercubic symmetry breaking induced by the Karsten-Wilczek ... More
Bulk-boundary correspondence for non-Hermitian Hamiltonians via Green functionsJan 31 2019Genuinely non-Hermitian topological phases can be realized in open systems with sufficiently strong gain and loss; in such phases, the Hamiltonian cannot be deformed into a gapped Hermitian Hamiltonian without energy bands touching each other. Comparing ... More
The rate of the convergence of the mean score in random sequence comparisonNov 11 2010Nov 17 2010We consider a general class of super-additive scores measuring the similarity of two independent sequences of $n$ i.i.d. letters from a finite alphabet. Our object of interest is the mean score by letter $l_n$. By the subadditivity $l_n$ is nondecreasing ... More
Simulations of Bunch Merging in a Beta Beam Decay RingSep 08 2011To further study neutrino oscillation properties a Beta Beam facility has been proposed. Beta decaying ions with high kinetic energy are stored in a storage ring ("Decay Ring") with straight sections to create pure focused (anti) electron neutrino beams. ... More
Anderson's Orthogonality Catastrophe for One-dimensional SystemsJan 21 2013Jun 17 2013We derive rigorously the leading asymptotics of the so-called Anderson integral in the thermodynamic limit for one-dimensional, non-relativistic, spin-less Fermi systems. The coefficient, $\gamma$, of the leading term is computed in terms of the S-matrix. ... More
Equation of state in (2+1) flavor QCD at high temperaturesNov 30 2018We calculate the Equation of State at high temperatures in (2+1) flavor QCD using the highly improved staggered quark (HISQ) action. We study the lattice spacing dependence of the pressure at high temperatures using lattices with temporal extent $N_{\tau}=6,~8,~10$ ... More
Polyakov loop correlators and cyclic Wilson loop from lattice QCDJan 29 2016We discuss color screening in 2+1 flavor QCD in terms of free energies of a static quark-antiquark pair. Thermal modifications of long distance correlations in quark-antiquark systems are studied in terms of static meson correlators. We calculate the ... More
Frontal Screens on Head-Mounted Displays to Increase Awareness of the HMD Users' State in Mixed Presence CollaborationMay 15 2019In the everyday context, e.g., a household, HMD users remain a part of the social life for Non-HMD users being co-located with them. Due to the social context situations arise that demand interaction between the HMD and the Non-HMD user. We focus on the ... More
Entropy Rates of the Multidimensional Moran Processes and GeneralizationsJan 13 2014The interrelationships of the fundamental biological processes natural selection, mutation, and stochastic drift are quantified by the entropy rate of Moran processes with mutation, measuring the long-run variation of a Markov process. The entropy rate ... More
A Population-centric Approach to the Beauty Contest GameMay 07 2010Dec 13 2014An population-centric analysis for a version of the p-beauty contest game is given for the two-player, finite population, and infinite population cases. Winning strategies are characterized in terms of iterative thinking relative to the population. To ... More
Learning a world model and planning with a self-organizing, dynamic neural systemJun 11 2003We present a connectionist architecture that can learn a model of the relations between perceptions and actions and use this model for behavior planning. State representations are learned with a growing self-organizing layer which is directly coupled ... More
Charts, Interaction-Free Grammars, and the Compact Representation of AmbiguityMay 12 1997Recently researchers working in the LFG framework have proposed algorithms for taking advantage of the implicit context-free components of a unification grammar [Maxwell 96]. This paper clarifies the mathematical foundations of these techniques, provides ... More
Studies in Cryptological CombinatoricsNov 24 2004The key-agreement problem (finding a private key to use for secret messages, otherwise referred to as the public-key distribution problem), was introduced by Diffie and Hellman in 1976. An approach to structuring key-agreement protocols via the use of ... More
Extending Classical Logic with Inductive DefinitionsMar 07 2000The goal of this paper is to extend classical logic with a generalized notion of inductive definition supporting positive and negative induction, to investigate the properties of this logic, its relationships to other logics in the area of non-monotonic ... More
A partonic description of the transverse target single-spin asymmetry in inclusive DISNov 15 2012The single-spin asymmetry of unpolarized leptons scattering deep-inelastically off transversely polarized nucleons is studied in a partonic picture within a collinear twist-3 framework. Since this observable is generated by multi-photon exchanges between ... More
The Classical Exchange Algebra of AdS5 x S5 String TheoryOct 22 2008Jan 07 2009The classical exchange algebra satisfied by the monodromy matrix of AdS5 x S5 string theory in the Green-Schwarz formulation is determined by using a first-order Hamiltonian formulation and by adding to the Bena-Polchinski-Roiban Lax connection terms ... More
How to compute the thermodynamics of a glass using a cloned liquidDec 02 1998The recently proposed strategy for studying the equilibrium thermodynamics of the glass phase using a molecular liquid is reviewed and tested in details on the solvable case of the $p$-spin model. We derive the general phase diagram, and confirm the validity ... More
An extension criterion for lattice actions on the circleMay 01 2009We establish a necessary and sufficient condition for an action of a lattice by homeomorphisms of the circle to extend continuously to the ambient locally compact group. This condition is expressed in terms of the real bounded Euler class of this action. ... More
The Complexity of Partition Functions on Hermitian MatricesApr 07 2010Partition functions of certain classes of "spin glass" models in statistical physics show strong connections to combinatorial graph invariants. Also known as homomorphism functions they allow for the representation of many such invariants, for example, ... More
The canonical decomposition of once-punctured torus bundlesDec 20 2001In this paper, we determine the canonical polyhedral decomposition of every hyperbolic once-punctured torus bundle over the circle. In fact, we show that the only ideal polyhedral decomposition that is straight in the hyperbolic structure and that is ... More
On the Pseudo-Schrödinger Equation approximation of the Transfer-Integral operator for 1-dimensional DNA modelsNov 19 2010The Transfer-Integral (TI) operator is a powerful method to investigate the statistical physics of 1-dimensional models, like those used to describe DNA denaturation. At the cost of a certain number of approximations, the TI equation can be reduced to ... More
Mirror graphs: graph theoretical characterization of reflection arrangements and finite Coxeter groupsSep 02 2016Mirror graphs were introduced by Bre\v{s}ar et al. in 2004 as an intriguing class of graphs: vertex-transitive, isometrically embeddable into hypercubes, having a strong connection with regular maps and polytope structure. In this article we settle the ... More
Forces between static-light mesonsAug 09 2010The isospin, spin and parity dependent potential of a pair of static-light mesons is computed using Wilson twisted mass lattice QCD with two flavors of degenerate dynamical quarks. From the results a simple rule can be deduced stating, which isospin, ... More
A topological version of the Poincaré-Birkhoff theorem with two fixed pointsOct 18 2010Mar 30 2011The main result of this paper gives a topological property satisfied by any homeomorphism of the annulus $\mathbb{A}=\mathbb{S}^1 \times [-1,1]$ isotopic to the identity and with at most one fixed point. This generalizes the classical Poincar\'e-Birkhoff ... More
Motions on n-Simplex Graphs with m-value memoryOct 01 2003We introduce the idea of an n-simplex graph and games upon simplicial complexes. We then define moves on a labeled graph and pose the problem of whether given two labelings of a graph it is possible to change one into another via these moves. We then ... More
Escort Evolutionary Game TheoryNov 09 2009Feb 24 2012A family of replicator-like dynamics, called the escort replicator equation, is constructed using information-geometric concepts and generalized information entropies and diverenges from statistical thermodynamics. Lyapunov functions and escort generalizations ... More
Pseudo-Riemannian metrics with prescribed scalar curvatureSep 22 2004Sep 22 2004We consider the following generalisation of a well-known problem in Riemannian geometry: When is a smooth real-valued function s on a given compact n-dimensional manifold M (with or without boundary) the scalar curvature of some smooth pseudo-Riemannian ... More
The Inherent Randomness of Evolving PopulationsMar 08 2013Mar 27 2013The entropy rates of the Wright-Fisher process, the Moran process, and generalizations are computed and used to compare these processes and their dependence on standard evolutionary parameters. Entropy rates are measures of the variation dependent on ... More
Explicit GL(2) trace formulas and uniform, mixed Weyl lawsDec 18 2012This thesis provides an explicit, general trace formula for the Hecke and Casimir eigenvalues of GL(2)-automorphic representations over a global field. In special cases, we obtain Selberg's original trace formula. Computations for the determinant of the ... More
A Determination of the Fine Structure Constant using Precision Measurements of Helium Fine StructureMar 13 2012Spectroscopic measurements of the helium atom are performed to high precision using an atomic beam apparatus and electro-optic laser techniques. These measurements, in addition to serving as a test of helium theory, also provide a new determination of ... More
Covering spaces of 3-orbifoldsAug 01 2005Jun 07 2006Let O be a compact orientable 3-orbifold with non-empty singular locus and a finite volume hyperbolic structure. (Equivalently, O is the quotient of hyperbolic 3-space by a lattice in PSL(2,C) with torsion.) Then we prove that O has a tower of finite-sheeted ... More
Some conditionally hard problems on links and 3-manifoldsFeb 26 2016Apr 27 2017We show that three natural decision problems about links and 3-manifolds are computationally hard, assuming some conjectures in complexity theory. The first problem is determining whether a link in the 3-sphere bounds a Seifert surface with Thurston norm ... More
Hilbertian InterpolationJun 25 2016I want to prove that all classical techniques of interpolation and approximation as Lagrange, Taylor, Hermite interpolations Beziers interpolants, Quasi interpolants, Box splines and others (radial splines, simplicial splines) are derived from a \textbf{unique} ... More
Subdifferential stability and subdifferential sum rulesDec 30 2018In the first part, we discuss the stability of the strong slope and of the subdifferential of a lower semicontinuous function with respect to Wijsman perturbations of the function, i.e. perturbations described via Wijsman convergence. In the second part, ... More
Higher indicators for some groups and their doublesApr 11 2010In this paper we explicitly determine all indicators for groups isomorphic to the semidirect product of two cyclic groups by an automorphism of prime order, as well as the generalized quaternion groups. We then compute the indicators for the Drinfel'd ... More
The FSZ properties of sporadic simple groupsOct 12 2016Apr 08 2017We investigate a possible connection between the $FSZ$ properties of a group and its Sylow subgroups. We show that the simple groups $G_2(5)$ and $S_6(5)$, as well as all sporadic simple groups with order divisible by $5^6$ are not $FSZ$, and that neither ... More
Quasitriangular structures of the double of a finite groupNov 27 2014Aug 22 2017We give a classification of all quasitriangular structures and ribbon elements of $\mathcal{D}(G)$ explicitly in terms of group homomorphisms and central subgroups. This can equivalently be interpreted as an explicit description of all braidings with ... More
Examples of non-FSZ p-groups for primes greater than threeOct 01 2016Apr 18 2017For any prime $p>3$ and $j\in\mathbb{N}$ we construct examples of non-$FSZ_{p^j}$ groups of order $p^{p^j+2j-1}$. In the special case of $j=1$ this yields groups of order $p^{p+1}$, which is the minimum possible order for a non-$FSZ$ $p$-group.
Simpler, Linear-Time Transitive Orientation via Lexicographic Breadth-First SearchMar 10 2015Comparability graphs are the undirected graphs whose edges can be directed so that the resulting directed graph is transitive. They are related to posets and have applications in scheduling theory. This paper considers the problem of finding a transitive ... More
DARWINNov 27 2011DARWIN is a design-study for a next-to-next generation experiment to directly detect WIMP dark matter in a detector based on a liquid xenon/liquid argon two-phase time projection chamber. This article describes the project, its goals and challenges, and ... More
The Coleman-Weinberg Phase Transition in Extended Higgs ModelsJul 16 1996In Coleman-Weinberg symmetry breaking, all dimensionful parameters vanish and the symmetry is broken by loop corrections. Before Coleman-Weinberg symmetry breaking in the Standard Model was experimentally ruled out, it had already been excluded on cosmological ... More
Universal Extra Dimensions and Kaluza-Klein Bound StatesSep 02 2004We study the bounds states of the Kaluza-Klein (KK) excitations of quarks in models of Universal Extra Dimensions. Such bound states may be detected at future lepton colliders in the cross section for the pair-production of KK-quarks near threshold. For ... More
How to extract data from proprietary software database systems using TCP/IP?Apr 26 2014May 11 2014This document is an white paper about how to connect reverse engineering and programing skills to extract data from a proprietary implementation of a database system to build EML-Tools for data format conversion into raw data. This article shows how to ... More
Equivariant classifying spaces and cdh descent for the homotopy K-theory of tame stacksApr 21 2016We construct geometric models for classifying spaces of linear algebraic groups in G-equivariant motivic homotopy theory, where G is a tame group scheme. As a consequence, we show that the equivariant motivic spectrum representing the homotopy K-theory ... More
Lectures on Reduce and Maple at UAM I - MexicoMay 25 2001These lectures give a brief introduction to the Computer Algebra systems Reduce and Maple. The aim is to provide a systematic survey of most important commands and concepts. In particular, this includes a discussion of simplification schemes and the handling ... More
Information Geometry and Evolutionary Game TheoryNov 09 2009The Shahshahani geometry of evolutionary game theory is realized as the information geometry of the simplex, deriving from the Fisher information metric of the manifold of categorical probability distributions. Some essential concepts in evolutionary ... More
Self-adaptive exploration in evolutionary searchFeb 05 2001We address a primary question of computational as well as biological research on evolution: How can an exploration strategy adapt in such a way as to exploit the information gained about the problem at hand? We first introduce an integrated formalism ... More
Classification in Feature-based Default Inheritance HierarchiesJun 04 1996Increasingly, inheritance hierarchies are being used to reduce redundancy in natural language processing lexicons. Systems that utilize inheritance hierarchies need to be able to insert words under the optimal set of classes in these hierarchies. In this ... More
Group Theory and Grammatical DescriptionMay 07 1998This paper presents a model for linguistic description based on group theory. A grammar in this model, or "G-grammar", is a collection of lexical expressions which are products of logical forms, phonological forms, and their inverses. Phrasal descriptions ... More
Morphological Cues for Lexical SemanticsJun 04 1996Most natural language processing tasks require lexical semantic information. Automated acquisition of this information would thus increase the robustness and portability of NLP systems. This paper describes an acquisition method which makes use of fixed ... More
NumGfun: a Package for Numerical and Analytic Computation with D-finite FunctionsFeb 16 2010May 31 2010This article describes the implementation in the software package NumGfun of classical algorithms that operate on solutions of linear differential equations or recurrence relations with polynomial coefficients, including what seems to be the first general ... More
Two-photon physicsJan 26 2006It is reviewed how Compton scattering sum rules relate low-energy nucleon structure quantities to the nucleon excitation spectrum. In particular, the GDH sum rule and recently proposed extensions of it will be discussed. These extensions are sometimes ... More
Coordination in Network Security Games: a Monotone Comparative Statics ApproachAug 20 2012Malicious softwares or malwares for short have become a major security threat. While originating in criminal behavior, their impact are also influenced by the decisions of legitimate end users. Getting agents in the Internet, and in networks in general, ... More
Electromagnetic Corrections to Low-Energy pi-pi ScatteringDec 21 1999Electromagnetic corrections to the low-energy pi+ pi- -> pi0 pi0 scattering amplitude at next-to-leading order in the chiral expansion are reviewed. Their effects on the corresponding scattering lengths are estimated and compared to the two-loop strong ... More
A note on the Declarative reading(s) of Logic ProgrammingMar 13 2000This paper analyses the declarative readings of logic programming. Logic programming - and negation as failure - has no unique declarative reading. One common view is that logic programming is a logic for default reasoning, a sub-formalism of default ... More
Model Prediction for the Transverse Single Target-Spin Asymmetry in inclusive DISMar 05 2013The single-spin asymmetry of unpolarized leptons scattering deep-inelastically off transversely polarized nucleons is discussed. This observable is generated by a two-photon exchange between lepton and nucleon. In a partonic description of the asymmetry ... More
Random systems and replica field theoryMar 09 1995Contents: I. Introduction II. Manifolds in random media III. Thermal fluctuations without disorder IV. Random forces V. Random potential: variational approach VI. Physical interpretation of the solution
Convex KKM maps, monotone operators and Minty variational inequalitiesMar 21 2015It is known that for convex sets, the KKM condition is equivalent to the finite intersection property. We use this equivalence to obtain a characterisation of monotone operators in terms of convex KKM maps and in terms of the existence of solutions to ... More
MALL proof equivalence is Logspace-complete, via binary decision diagramsFeb 06 2015Apr 17 2015Proof equivalence in a logic is the problem of deciding whether two proofs are equivalent modulo a set of permutation of rules that reflects the commutative conversions of its cut-elimination procedure. As such, it is related to the question of proofnets: ... More
Equilibration of complexes of DNA and H-NS proteins on charged surfaces: A coarse-grained model point of viewSep 22 2014The Histone-like Nucleoid Structuring protein (H-NS) is a nucleoid-associated protein, which is involved in both gene regulation and DNA compaction. Although it is a key player in genome organization by forming bridges between DNA duplexes, the precise ... More
Applications of quasitriangular structures for the doubles of purely non-abelian groupsAug 22 2017We further investigate the quasitriangular structures of $\mathcal{D}(G)$ and obtain formulas for their $S$- and $T$-matrices. This is then leveraged to obtain a variety of new identities for higher Frobenius-Schur indicators and the fusion ring. We are ... More
Cohomology of projective schemes: From annihilators to vanishingSep 25 2002We provide bounds on the Castelnuovo-Mumford regularity in terms of ``defining equations'' by using elements that annihilates some cohomology modules, inspired by works of Miyazaki, Nagel, Schenzel and Vogel. The elements in these annihilators are provided ... More
Projective schemes: What is Computable in low degree?Oct 30 2002This article first presents two examples of algorithms that extracts information on scheme out of its defining equations. We also give a review on the notion of Castelnuovo-Mumford regularity, its main properties (in particular its relation to computational ... More
Liaison of varieties of small dimension and deficiency modulesOct 29 2002Sep 11 2003This article studies the behaviour under liaison of the deficiency modules of schemes that are not assumed to be Cohen-Macaulay. Our study uses in particular a generalization of Serre duality, and gives a satisfactory description of this behaviour in ... More
The canonical Cartan bundle and connection in CR geometryMay 02 2006May 29 2006We give a differential geometric description of the Cartan (or tractor) bundle and its canonical connection in CR geometry, thus offering a direct, alternative, definition to the usual abstract approach.
The Legendrian knot complement problemApr 18 2016Aug 11 2018We prove that every Legendrian knot in the tight contact structure of the 3-sphere is determined by the contactomorphism type of its exterior. Moreover, by giving counterexamples we show this to be not true for Legendrian links in the tight 3-sphere. ... More
The Adams-Novikov spectral sequence and Voevodsky's slice towerNov 17 2013Oct 03 2015We show that the spectral sequence converging to the stable homotopy groups of spheres, induced by the Betti realization of the slice tower for the motivic sphere spectrum, agrees with the Adams-Novikov spectral sequence, after a suitable re-indexing. ... More
Convergence of Voevodsky's slice towerDec 31 2011Mar 07 2013We consider Voevodsky's slice tower for a finite spectrum E in the motivic stable homotopy category over a perfect field k. In case k has finite cohomological dimension (in characteristic two, we also require that k is infinite), we show that the slice ... More
Calendrical Interpretation of Spirals in Irish Megalithic ArtFeb 11 2019The tumuli of Newgrange and Knowth in Ireland are among the most monumental heritages of the Neolithic era. The megalithic constructions date back to around 3'200 BC, centuries before the completion of Stonehenge and the Egyptian pyramids. Passageways ... More
Slow dynamics for the dilute Ising model in the phase coexistence regionJun 13 2012In this paper we consider the Glauber dynamics for a disordered ferromagnetic Ising model, in the region of phase coexistence. It was conjectured several decades ago that the spin autocorrelation decays as a negative power of time [Huse and Fisher, Phys. ... More
A Note on the Space Complexity of Fast D-Finite Function EvaluationSep 23 2012We state and analyze a generalization of the "truncation trick" suggested by Gourdon and Sebah to improve the performance of power series evaluation by binary splitting. It follows from our analysis that the values of D-finite functions (i.e., functions ... More
Overview on All Reactions Linked to GPDsJul 14 2002A short overview is given on how generalized parton distributions (GPDs) enter in a variety of hard exclusive processes such as deeply virtual Compton scattering (DVCS) and hard meson electroproduction reactions on the nucleon. We firstly discuss the ... More
Real and Virtual Compton Scattering off the NucleonJul 21 2000A review is given of the very recent developments in the fields of real and virtual Compton scattering off the nucleon. Both real and virtual Compton scattering reactions are discussed at low outgoing photon energy where one accesses polarizabilities ... More