Results for "Marc Heinrich"

total 7169took 0.10s
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 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
Enhanced quantum tunnelling induced by disorderMay 09 2008We reconsider the problem of the enhancement of tunnelling of a quantum particle induced by disorder of a one-dimensional tunnel barrier of length $L$, using two different approximate analytic solutions of the invariant imbedding equations of wave propagation ... More
Mean Free Path in Disordered Multichannel Tight-Binding WiresMar 13 2007Transport in a disordered tight-binding wire involves a collection of different mean free paths resulting from the distinct fermi points, which correspond to the various scattering channels of the wire. The generalization of Thouless' relation between ... More
Exact transmission moments in one-dimensional weak localization and single-parameter scalingJul 23 2003We obtain for the first time the expressions for the mean and the variance of the transmission coefficient for an Anderson chain in the weak localization regime, using exact expansions of the complex transmission- and reflection coefficients to fourth ... More
The space of Cohen-Macaulay curvesMar 24 2014One can consider the Hilbert scheme as a natural compactification of the space of smooth projective curves with fixed Hilbert polynomial. Here we consider a different modular compactification, namely the functor CM parameterizing curves together with ... More
Diophantine Approximation on varieties V: Algebraic independence criteriaJan 10 2010For a tuple $(\theta_1,..,\theta_M)$ of complex number, buliding on the approximation techniques in earlier papers of this series, this paper engages in deducing lower estimates on the transcendence degree of the field generated by $\theta_1, ..., \theta_M$ ... 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
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
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
Entropy, biological evolution and the psychological arrow of timeJan 13 2014Nov 30 2015We argue that in Universes where future and past differ only by the entropy content a psychological arrow of time pointing in the direction of entropy increase can arise from natural selection in biological evolution. We show that this effect can be demonstrated ... More
Diffuse planar phase boundaries in a two-phase fluid with one very dense phaseJul 13 2013This note studies Navier-Stokes-Allen-Cahn models for compressible fluids that are mixtures of two incompressible phases whose density ratio eps=rho_1/rho_2 is very small. Under a natural assumption on the mixing energy, it shows the existence of diffuse ... More
Distribution of Aligned Letter Pairs in Optimal Alignments of Random SequencesNov 23 2012Considering the optimal alignment of two i.i.d. random sequences of length $n$, we show that when the scoring function is chosen randomly, almost surely the empirical distribution of aligned letter pairs in all optimal alignments converges to a unique ... More
Letter Change Bias and Local Uniqueness in Optimal Sequence AlignmentsApr 24 2013Considering two optimally aligned random sequences, we investigate the effect on the alignment score caused by changing a random letter in one of the two sequences. Using this idea in conjunction with large deviations theory, we show that in alignments ... More
Optimal rates for finite mixture estimationJul 15 2015We study the rates of estimation of finite mixing distributions, that is, the parameters of the mixture. We prove that under some regularity and strong identifiability conditions, around a given mixing distribution with $m_0$ components, the optimal local ... More
Sterile Neutrino Shortcuts in Asymmetrically Warped Extra DimensionsAug 23 2018Light sterile neutrinos are a popular extension of the Standard Model and are being discussed as a possible explanation for various neutrino oscillation anomalies, including the LSND, MiniBooNE, Reactor and Gallium anomalies. In order to avoid inconsistencies ... More
Symmetrizations of RMHD equations and stability of relativistic current-vortex sheetsFeb 09 2012Feb 05 2013We consider the equations of relativistic magnetohydrodynamics (RMHD) in the case of special relativity. For the fluid rest frame a nonconservative reformulation of the RMHD equations gives a symmetric system for the vector of primitive (physical) variables. ... 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
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
On a Problem in Quantum SummationSep 07 2001We consider the computation of the mean of sequences in the quantum model of computation. We determine the query complexity in the case of sequences which satisfy a $p$-summability condition for $1\le p<2$. This settles a problem left open in Heinrich ... 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 Component Factor Group G/G_0 of a Pro-Lie Group GDec 12 2018A pro-Lie group $G$ is a topological group such that $G$ is isomorphic to the projective limit of all quotient groups $G/N$ (modulo closed normal subgroups $N$) such that $G/N$ is a finite dimensional real Lie group. A topological group is almost connected ... 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
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
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
On Complexity, Energy- and Implementation-Efficiency of Channel DecodersMar 19 2010Future wireless communication systems require efficient and flexible baseband receivers. Meaningful efficiency metrics are key for design space exploration to quantify the algorithmic and the implementation complexity of a receiver. Most of the current ... More
Asymptotic goodness-of-fit tests for the Palm mark distribution of stationary point processes with correlated marksOct 01 2014We consider spatially homogeneous marked point patterns in an unboundedly expanding convex sampling window. Our main objective is to identify the distribution of the typical mark by constructing an asymptotic $\chi^2$-goodness-of-fit test. The corresponding ... More
A Monte Carlo Approach to the Fluctuation Problem in Optimal Alignments of Random StringsNov 23 2012The problem of determining the correct order of fluctuation of the optimal alignment score of two random strings of length $n$ has been open for several decades. It is known that the biased expected effect of a random letter-change on the optimal score ... 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
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
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
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
Critical Point for Maximum Likelihood Decoding of Linear Block CodesApr 10 2005In this letter, the SNR value at which the error performance curve of a soft decision maximum likelihood decoder reaches the slope corresponding to the code minimum distance is determined for a random code. Based on this value, referred to as the critical ... More
Polar Codes: Graph Representation and DualityDec 02 2013In this paper, we present an iterative construction of a polar code and develop properties of the dual of a polar code. Based on this approach, belief propagation of a polar code can be presented in the context of low-density parity check codes.
Recurrence relations for Apostol-Bernoulli , -Euler and -Genocchi polynomials of higher orderSep 15 2017In \cite{luo2006,luosri2005}, Luo and Srivastava introduced some generalizations of the Apostol -Bernoulli polynomials and the Apostol-Euler polynomials. The main object of this paper is to extend the result of \cite{prevost2010} to these generalized ... More
Shifted moments of L functions and moments of theta functionsDec 03 2015Dec 04 2015Assuming the Riemann Hypothesis, Soundararajan showed that $\displaystyle{\int_{0}^{T} \vert \zeta(1/2 + it)\vert^{2k} \ll T(\log T)^{k^2 + \epsilon}}$ . His method was used by Chandee to obtain upper bounds for shifted moments of the Riemann Zeta function. ... More
On the behavior of Castelnuovo-Mumford regularity with respect to some functorsJun 19 2007We investigate the behavior of Castelnuovo-Mumford regularity with respect to some classical functors : Tor, the Frobenius functor in positive characteristic, taking a power or a product (on ideals). These generalizes and refines previous results on these ... 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
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.
Arithmetic of rationaly connected quintic 3-folds over finite and function fieldsOct 23 2007We prove that both classical Chevalley-Warning-Ax and Tsen theorems hold for the blowing up of a quintic 3-fold along a line of multiplicity 3. Both proofs, which are of the same spirit than the original ones, involve the description of this blowing-up ... 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
Subderivative-subdifferential duality formulaNov 12 2016Mar 05 2017We provide a formula linking the radial subderivative to other subderivatives and subdifferentials for arbitrary extended real-valued lower semicontinuous functions.
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
Expanders, rank and graphs of groupsMar 08 2004Apr 01 2005Let G be a finitely presented group, and let {G_i} be a collection of finite index normal subgroups that is closed under intersections. Then, we prove that at least one of the following must hold: 1. G_i is an amalgamated free product or HNN extension, ... More
TernaryNet: Faster Deep Model Inference without GPUs for Medical 3D Segmentation using Sparse and Binary ConvolutionsJan 29 2018Deep convolutional neural networks (DCNN) are currently ubiquitous in medical imaging. While their versatility and high quality results for common image analysis tasks including segmentation, localisation and prediction is astonishing, the large representational ... More
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
On the origin of Hilbert GeometryJul 08 2014In this brief essay we succinctly comment on the historical origin of Hilbert geometry. In particular, we give a summary of the letter in which David Hilbert informs his friend and colleague Felix Klein about his discovery of this geometry. The present ... More
Discussion of "Second order topological sensitivity analysis" by J. Rocha de Faria et alAug 28 2007The article by J. Rocha de Faria et al. under discussion is concerned with the evaluation of the perturbation undergone by the potential energy of a domain $\Omega$ (in a 2-D, scalar Laplace equation setting) when a disk $B_{\epsilon}$ of small radius ... 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
On Pasch's Axiom and Desargues' Theorem in Busemann's workOct 25 2016In this note, we discuss the role played by the techniques from the "foundations of geometry" and in particular by Desargues' Theorem in the work of Busemann. This note is part of a forthcoming edition of Busemann's collected papers.
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
Odd Character Degrees for Sp(2n,2)Feb 25 2011We check McKay conjecture on character degrees for the case of symplectic groups over the field with two elements Sp(2n,2) and the prime 2. Then we check the inductive McKay condition (Isaacs-Malle-Navarro 2007) for Sp(4,2^m) and all primes.
A polynomial upper bound on Reidemeister movesFeb 01 2013Dec 11 2014We prove that any diagram of the unknot with c crossings may be reduced to the trivial diagram using at most (236 c)^{11} Reidemeister moves. Moreover, every diagram in this sequence has at most (7 c)^2 crossings. We also prove a similar theorem for split ... More
Large groups, Property (tau) and the homology growth of subgroupsSep 02 2005Dec 01 2005We investigate the homology of finite index subgroups G_i of a given finitely presented group G. Specifically, we examine d_p(G_i), which is the dimension of the first homology of G_i, with mod p coefficients. We say that a collection of finite index ... 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
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
Automorphisms of the doubles of purely non-abelian finite groupsNov 04 2013Jun 08 2014Using a recent classification of $\operatorname{End}(\mathcal{D}(G))$, we determine a number of properties for $\operatorname{Aut}(\mathcal{D}(G))$, where $\mathcal{D}(G)$ is the Drinfel'd double of a finite group $G$. Furthermore, we completely describe ... More
A family of non-FSZ finite symplectic groupsJan 31 2019Let $p$ be an odd prime with $p\equiv1\bmod 4$. Then for any odd power $q$ of $p$ and a positive integer $j$ we show that the groups $\text{Sp}_{p^j+1}(q),\text{PSp}_{p^j+1}(q)$, and their Sylow $p$-subgroups are non-$FSZ_{p^j}$.
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
Some behaviors of FSZ groups under central products, central quotients, and regular wreath productsApr 18 2017Jun 09 2017We show that any group $G$ with a non-$FSZ_m$ quotient by a central cyclic subgroup also provides a non-$FSZ_m$ group of order $m|G|$ obtained as a central product of $G$ with a cyclic group. We then construct, for every prime $p>3$ and $j\in\mathbb{N}$, ... More
A differentiation theorem for uniform measuresAug 15 2013Using the notion of higher-order Fourier dimension introduced in \cite{M2} (which was a sort of psuedorandomness condition stemming from the Gowers norms of Additive Combinatorics), we prove a maximal theorem and corresponding differentiation theorem ... More
Toward an algebraic theory of Welschinger invariantsAug 07 2018Let $S$ be a smooth del Pezzo surface over a field $k$ of characteristic $\neq 2, 3$. We define an invariant in the Grothendieck-Witt ring $GW(k)$ for "counting" rational curves in a curve class $D$ of fixed positive degree (with respect to the anti-canonical ... More
Counting cosets of unimodular groups over Dedekind domainsJan 19 2011In this paper, a formula for the calculation of the number of right cosets contained in a double coset with respect to a unimodular group over a Dedekind domain is developed, and applications of this formula in the theory of congruence subgroups -- an ... More
Upper semismooth functions and the subdifferential determination propertyMar 08 2017In this paper, an upper semismooth function is defined to be a lower semicontinuous function whose radial subderivative satisfies a mild directional upper semicontinuity property. Examples of upper semismooth functions are the proper lower semicontinuous ... More
On the Complexity of Recognizing S-composite and S-prime GraphsMay 04 2012Jan 16 2013S-prime graphs are graphs that cannot be represented as nontrivial subgraphs of nontrivial Cartesian products of graphs, i.e., whenever it is a subgraph of a nontrivial Cartesian product graph it is a subgraph of one the factors. A graph is S-composite ... More