Results for "Sven Kreiss"

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MonoLoco: Monocular 3D Pedestrian Localization and Uncertainty EstimationJun 14 2019We tackle the fundamentally ill-posed problem of 3D human localization from monocular RGB images. Driven by the limitation of neural networks outputting point estimates, we address the ambiguity in the task with a new neural network predicting confidence ... More
PifPaf: Composite Fields for Human Pose EstimationMar 15 2019Apr 05 2019We propose a new bottom-up method for multi-person 2D human pose estimation that is particularly well suited for urban mobility such as self-driving cars and delivery robots. The new method, PifPaf, uses a Part Intensity Field (PIF) to localize body parts ... More
PifPaf: Composite Fields for Human Pose EstimationMar 15 2019We propose a new bottom-up method for multi-person 2D human pose estimation that is particularly well suited for urban mobility such as self-driving cars and delivery robots. The new method, PifPaf, uses a Part Intensity Field (PIF) to localize body parts ... More
MonoLoco: Monocular 3D Pedestrian Localization and Uncertainty EstimationJun 14 2019Aug 20 2019We tackle the fundamentally ill-posed problem of 3D human localization from monocular RGB images. Driven by the limitation of neural networks outputting point estimates, we address the ambiguity in the task by predicting confidence intervals through a ... More
Rethinking Person Re-Identification with ConfidenceJun 11 2019A common challenge in person re-identification systems is to differentiate people with very similar appearances. The current learning frameworks based on cross-entropy minimization are not suited for this challenge. To tackle this issue, we propose to ... More
Higher Order Cut Elements for the Wave EquationAug 10 2016The scalar wave equation is solved using higher order immersed finite elements. We demonstrate that higher order convergence can be obtained. Small cuts with the background mesh are stabilized by adding penalty terms to the weak formulation. This ensures ... More
Bounds for the threshold amplitude for plane Couette flowFeb 03 2003We prove nonlinear stability for finite amplitude perturbations of plane Couette flow. A bound of the solution of the resolvent equation in the unstable complex half-plane is used to estimate the solution of the full nonlinear problem.The result is a ... More
Crowd-Robot Interaction: Crowd-aware Robot Navigation with Attention-based Deep Reinforcement LearningSep 24 2018Feb 19 2019Mobility in an effective and socially-compliant manner is an essential yet challenging task for robots operating in crowded spaces. Recent works have shown the power of deep reinforcement learning techniques to learn socially cooperative policies. However, ... More
Crowd-Robot Interaction: Crowd-aware Robot Navigation with Attention-based Deep Reinforcement LearningSep 24 2018Mobility in an effective and socially-compliant manner is an essential yet challenging task for robots operating in crowded spaces. Recent works have shown the power of deep reinforcement learning techniques to learn socially cooperative policies. However, ... More
Decoupling Theoretical Uncertainties from Measurements of the Higgs BosonDec 31 2013Apr 01 2015We develop a technique to present Higgs coupling measurements, which decouple the poorly defined theoretical uncertainties associated to inclusive and exclusive cross section predictions. The technique simplifies the combination of multiple measurements ... More
Problems which are well-posed in a generalized sense with applications to the Einstein equationsFeb 13 2006Jun 06 2006In the harmonic description of general relativity, the principle part of Einstein equations reduces to a constrained system of 10 curved space wave equations for the components of the space-time metric. We use the pseudo-differential theory of systems ... More
Geometric Boundary Data for the Gravitational FieldFeb 04 2013Feb 25 2014An outstanding issue in the treatment of boundaries in general relativity is the lack of a local geometric interpretation of the necessary boundary data. For the Cauchy problem, the initial data is supplied by the 3-metric and extrinsic curvature of the ... More
The Well-posedness of the Null-Timelike Boundary Problem for Quasilinear WavesOct 06 2010May 17 2011The null-timelike initial-boundary value problem for a hyperbolic system of equations consists of the evolution of data given on an initial characteristic surface and on a timelike worldtube to produce a solution in the exterior of the worldtube. We establish ... More
On the well posedness of Robinson Trautman Maxwell solutionsAug 14 2007We show that the so called Robinson-Trautman-Maxwell equations do not constitute a well posed initial value problem. That is, the dependence of the solution on the initial data is not continuous in any norm built out from the initial data and a finite ... More
Boundary estimates for the elastic wave equation in almost incompressible materialsMay 02 2011We study the half-plane problem for the elastic wave equation subject to a free surface boundary condition, with particular emphasis on almost incompressible materials. A normal mode analysis is developed to estimate the solution in terms of the boundary ... More
Temporal upscaling in micro magnetism via heterogeneous multiscale methodsMar 15 2016We consider a multiscale strategy addressing the disparate temporal scales in the Landau-Lifschitz equations of micro-magnetism. At the microscopic scale, the magnetisation dynamics is driven by either a high frequency field when considering ferromagnetic ... More
Elastic wave propagation in complex geometries: A qualitative comparison between two high order finite difference methodsNov 24 2015We compare two high order finite-difference methods that solve the elastic wave equation in two dimensional domains with curved boundaries and material discontinuities. Two numerical experiments are designed with focus on wave boundary interaction, the ... More
High order finite difference methods for the wave equation with non-conforming grid interfacesSep 25 2015We use high order finite difference methods to solve the wave equation in the second order form. The spatial discretization is performed by finite difference operators satisfying a summation-by-parts property. The focus of this work is on the numerical ... More
Correlation bounds, mixing and m-dependence under random time-varying network distances with an application to Cox-ProcessesJun 07 2019We will consider multivariate stochastic processes indexed either by vertices or pairs of vertices of a dynamic network. Under a dynamic network we understand a network with a fixed vertex set and an edge set which changes randomly over time. We will ... More
Testing the well-posedness of characteristic evolution of scalar wavesMay 30 2013Recent results have revealed a critical way in which lower order terms affect the well-posedness of the characteristic initial value problem for the scalar wave equation. The proper choice of such terms can make the Cauchy problem for scalar waves well ... More
The RooStats ProjectSep 06 2010Feb 01 2011RooStats is a project to create advanced statistical tools required for the analysis of LHC data, with emphasis on discoveries, confidence intervals, and combined measurements. The idea is to provide the major statistical techniques as a set of C++ classes ... More
Constraint-preserving Sommerfeld conditions for the harmonic Einstein equationsDec 08 2006The principle part of Einstein equations in the harmonic gauge consists of a constrained system of 10 curved space wave equations for the components of the space-time metric. A new formulation of constraint-preserving boundary conditions of the Sommerfeld ... More
Initial-boundary value problems for second order systems of partial differential equationsDec 06 2010We develop a well-posedness theory for second order systems in bounded domains where boundary phenomena like glancing and surface waves play an important role. Attempts have previously been made to write a second order system consisting of n equations ... More
Boundary conditions for coupled quasilinear wave equations with application to isolated systemsJul 21 2008We consider the initial-boundary value problem for systems of quasilinear wave equations on domains of the form $[0,T] \times \Sigma$, where $\Sigma$ is a compact manifold with smooth boundaries $\partial\Sigma$. By using an appropriate reduction to a ... More
On the range of validity of the autoregressive sieve bootstrapJan 30 2012We explore the limits of the autoregressive (AR) sieve bootstrap, and show that its applicability extends well beyond the realm of linear time series as has been previously thought. In particular, for appropriate statistics, the AR-sieve bootstrap is ... More
Light propagation in the gravitational field of N arbitrarily moving bodies in the 1.5PN approximation for high-precision astrometryMay 28 2016Jul 11 2016High-precision astrometry on sub-micro-arcsecond level in angular resolution requires accurate determination of the trajectory of a light-signal from the celestial light source through the gravitational field of the Solar system toward the observer. In ... More
Meson Interferometry and the Quest for Quark-Gluon MatterDec 05 2001We point out what we may learn from the investigation of identical two-particle interferometry in ultrarelativistic heavy ion collisions if we assume a particular model scenario by the formation of a thermalized quark-gluon plasma hadronizing via a first-order ... More
Studies in Random Geometries: Hypercubic Random Surfaces and Simplicial Quantum GravityMay 08 1998We analyze two models of random geometries~: planar hyper-cubic random surfaces and four dimensional simplicial quantum gravity. We show for the hyper-cubic random surface model that a geometrical constraint does not change the critical properties of ... More
The nonparametric LAN expansion for discretely observed diffusionsFeb 06 2018Consider a scalar reflected diffusion $(X_t)_{t\geq 0}$, where the unknown drift function $b$ is modelled nonparametrically. We show that in the low frequency sampling case, when the sample consists of $(X_0,X_\Delta,...,X_{n\Delta})$ for some fixed sampling ... More
On the Pierce-Birkhoff Conjecture for Smooth Affine Surfaces over Real Closed FieldsOct 27 2008Feb 25 2009We will prove that the Pierce-Birkhoff Conjecture holds for non-singular two-dimensional affine real algebraic varieties over real closed fields, i.e., if W is such a variety, then every piecewise polynomial function on W can be written as suprema of ... More
About Cartan-Subalgebras in Lie-Algebras associated to Associative AlgebrasJul 21 2012We study Cartan-Subalgebras of Lie-Algebras associated to associative algebras.
Quantum and classical probability as Bayes-optimal observationJan 20 2006We propose a simple abstract formalisation of the act of observation, in which the system and the observer are assumed to be in a pure state and their interaction deterministically changes the states such that the outcome can be read from the state of ... More
Strongly regular graphs with the 7-vertex conditionJan 27 2014The $t$-vertex condition, for an integer $t\ge 2$, was introduced by Hestenes and Higman in 1971, providing a combinatorial invariant defined on edges and non-edges of a graph. Finite rank 3 graphs satisfy the condition for all values of $t$. Moreover, ... More
The Steady-State Behavior of Multivariate Exponentially Weighted Moving Average Control ChartsAug 15 2018Multivariate Exponentially Weighted Moving Average, MEWMA, charts are popular, handy and effective procedures to detect distributional changes in a stream of multivariate data. For doing appropriate performance analysis, dealing with the steady-state ... More
On the Union-Closed Set ConjectureJul 04 2016Jul 06 2016We provide a simple proof for the union-closed sets conjecture, a long-standing open problem in set theory with immediate applications to graph theory, number theory, and order-theory.
Geometric Decomposition of Feed Forward Neural NetworksDec 08 2016There have been several attempts to mathematically understand neural networks and many more from biological and computational perspectives. The field has exploded in the last decade, yet neural networks are still treated much like a black box. In this ... More
Local disorder, topological ground state degeneracy and entanglement entropy, and discrete anyonsAug 12 2016May 19 2017In this comprehensive study of Kitaev's abelian models defined on a graph embedded on a closed orientable surface, we provide complete proofs of the topological ground state degeneracy, the absence of local order parameters, compute the entanglement entropy ... More
Symmetry of solutions to nonlocal nonlinear boundary value problems in radial setsDec 09 2015For open radial sets $\Omega\subset \mathbb{R}^N$, $N\geq 2$ we consider the nonlinear problem \[ (P)\quad Iu=f(|x|,u) \quad\text{in $\Omega$,}\quad u\equiv 0\quad \text{on $\mathbb{R}^N\setminus \Omega$ and }\lim_{|x|\to\infty} u(x)=0, \] where $I$ is ... More
Electron spin filter and polarizer in a standing light waveApr 21 2016Nov 29 2017We demonstrate the theoretical feasibility of spin-dependent diffraction and spin-polarization of an electron in two counter-propagating, circularly polarized laser beams. The spin-dynamics appears in a two-photon process of the Kapitza-Dirac effect in ... More
Simple illustrations of range-dependence and 3-D effects by normal-mode sound propagation modellingApr 08 2016As is well known, the sound-speed profile has significant effects on underwater acoustic sound propagation. These effects can be quantified by normal-mode models, for example. The basic case is a laterally homogeneous medium, for which the sound speed ... More
Light propagation in the gravitational field of N arbitrarily moving bodies in 1PN approximation for high-precision astrometrySep 24 2015Jul 24 2017The light-trajectory in the gravitational field of N extended bodies in arbitrary motion is determined in the first post-Newtonian approximation. According to the theory of reference systems, the gravitational fields of these massive bodies are expressed ... More
An introduction into (motivic) Donaldson-Thomas theoryJan 18 2016The aim of the paper is to provide a rather gentle introduction into Donaldson-Thomas theory using quivers with potential. The reader should be familiar with some basic knowledge in algebraic or complex geometry. The text contains many examples and exercises ... More
Compact Linearization for Binary Quadratic Problems Comprising Linear ConstraintsAug 23 2018In this paper, the compact linearization approach originally proposed for binary quadratic programs with assignment constraints is generalized to such programs with arbitrary linear equations and inequalities that have positive coefficients and right ... More
Compact Linearization for Binary Quadratic Problems subject to Linear EquationsDec 15 2017In this paper it is shown that the compact linearization approach, that has been previously proposed only for binary quadratic problems with assignment constraints, can be generalized to arbitrary linear equations with positive coefficients which considerably ... More
Light deflection in binary starsAug 08 2012The light deflection of one component of a binary system due to the gravitational field of the other component is investigated. While this relativistic effect has not been observed thus far, the question arises that whether this effect becomes detectable ... More
Hard QCD Results with Jets at the LHCJan 24 2012Jan 25 2012Hard QCD results in proton-proton collisions at sqrt(s) = 7 TeV with jets from data recorded up to the end of 2010 by the CMS and ATLAS experiments at the LHC are reported. Inclusive jet and di-jet cross section measurements as well as observables sensitive ... More
Stability conditions on generic complex toriAug 22 2007Aug 24 2007In this paper we describe a simply connected component of the complex manifold of stability conditions on the bounded derived category of a generic complex torus of any dimension. A torus is called generic if there are no nontrivial integral (p,p)-classes. ... More
Büchi complementation made tightFeb 12 2009The precise complexity of complementing B\"uchi automata is an intriguing and long standing problem. While optimal complementation techniques for finite automata are simple - it suffices to determinize them using a simple subset construction and to dualize ... More
Shuffling Yeast Gene Expression DataJun 20 2000A new method to sort gene expression patterns into functional groups is presented. The method is based on a sorting algorithm using a non-local similarity score, which takes all other patterns in the dataset into account. The method is therefore very ... More
A Cyclic Orbifold Theory for Holomorphic Vertex Operator Algebras and ApplicationsNov 29 2016In this thesis we develop an orbifold theory for a finite, cyclic group G acting on a suitably regular, holomorphic vertex operator algebra V. To this end we describe the fusion algebra of the fixed-point vertex operator subalgebra V^G and show that V^G ... More
Light propagation in the gravitational field of one arbitrarily moving pointlike body in the 2PN approximationDec 07 2016An analytical solution for the light trajectory in the near-zone of the gravitational field of one pointlike body in arbitrary slow-motion in the post-post-Newtonian approximation is presented in harmonic gauge. Expressions for total light deflection ... More
On the Facets of the Secondary PolytopeAug 18 2009Jul 26 2010The secondary polytope of a point configuration A is a polytope whose face poset is isomorphic to the poset of all regular subdivisions of A. While the vertices of the secondary polytope - corresponding to the triangulations of A - are very well studied, ... More
Genocchi Numbers and f-Vectors of Simplicial BallsFeb 07 2007Sep 26 2007The Genocchi numbers are the coefficients of the generating function 2t/(e^t+1). In this note we will give an equation for simplicial balls which involves this numbers. It relates the number of faces in the interior of the ball with the number of faces ... More
Donaldson-Thomas invariants vs. intersection cohomology for categories of homological dimension oneDec 10 2015The present paper is an extension of a previous paper written in collaboration with Markus Reineke dealing with quiver representations. The aim of the paper is to generalize the theory and to provide a comprehensive theory of Donaldson-Thomas invariants ... More
New nonbinary code bounds based on divisibility argumentsJun 16 2016May 17 2017For $q,n,d \in \mathbb{N}$, let $A_q(n,d)$ be the maximum size of a code $C \subseteq [q]^n$ with minimum distance at least $d$. We give a divisibility argument resulting in the new upper bounds $A_5(8,6) \leq 65$, $A_4(11,8)\leq 60$ and $A_3(16,11) \leq ... More
C*-simplicity of locally compact Powers groupsMay 28 2015Jan 21 2016In this article we initiate research on locally compact C*-simple groups. We first show that every C*-simple group must be totally disconnected. Then we study C*-algebras and von Neumann algebras associated with certain groups acting on trees. After formulating ... More
Semidefinite programming bounds for constant weight codesMar 15 2017For nonnegative integers $n,d,w$, let $A(n,d,w)$ be the maximum size of a code $C \subseteq \mathbb{F}_2^n$ with constant weight $w$ and minimum distance at least $d$. We consider two semidefinite programs based on quadruples of code words that yield ... More
The Solar Neutrino Problem in the Presence of Flavor Changing Neutrino InteractionsJul 19 1997Aug 16 1997We study the effects of flavor changing neutrino interactions on the resonant conversion of solar neutrinos. In particular, we describe how the regions in the $Delta m^2 - sin^2 2theta$ plane that are consistent with the four solar neutrino experiments ... More
alpha_s at low Q^2 from e+e- and tau dataJun 02 2001It has been shown in recent analyses by ALEPH [1] and OPAL [2] that precision QCD tests are possible with hadronic tau decays by comparing spectral moments of the hadronic decay ratio of the tau with QCD calculations. In principle e+e- data can be used ... More
Logarithmic corrections of the avalanche distributions of sandpile models at the upper critical dimensionJun 29 1998We study numerically the dynamical properties of the BTW model on a square lattice for various dimensions. The aim of this investigation is to determine the value of the upper critical dimension where the avalanche distributions are characterized by the ... More
The nonparametric LAN expansion for discretely observed diffusionsFeb 06 2018Nov 08 2018Consider a scalar reflected diffusion $(X_t:t\geq 0)$, where the unknown drift function $b$ is modelled nonparametrically. We show that in the low frequency sampling case, when the sample consists of $(X_0,X_\Delta,...,X_{n\Delta})$ for some fixed sampling ... More
Partial Evaluation for Efficient Access to Inheritance LexiconsAug 25 1998Multiple default inheritance formalisms for lexicons have attracted much interest in recent years. I propose a new efficient method to access such lexicons. After showing two basic strategies for lookup in inheritance lexicons, a compromise is developed ... More
A Natural Quadratic Approach to the Generalized Graph Layering ProblemAug 12 2019We propose a new exact approach to the generalized graph layering problem that is based on a particular quadratic assignment formulation. It expresses, in a natural way, the associated layout restrictions and several possible objectives, such as a minimum ... More
Compact Linearization for Binary Quadratic Problems subject to Assignment ConstraintsOct 17 2016We prove new necessary and sufficient conditions to carry out a compact linearization approach for a general class of binary quadratic problems subject to assignment constraints as it has been proposed by Liberti in 2007. The new conditions resolve inconsistencies ... More
Local disorder, topological ground state degeneracy and entanglement entropy, and discrete anyonsAug 12 2016Aug 19 2016In this comprehensive study of Kitaev's abelian models defined on a graph embedded on a closed orientable surface, we provide complete proofs of the topological ground state degeneracy, the absence of local order parameters, compute the entanglement entropy ... More
Light propagation in the gravitational field of N arbitrarily moving bodies in 1PN approximation for high-precision astrometrySep 24 2015Mar 16 2016The light-trajectory in the gravitational field of N extended bodies in arbitrary motion is determined in the first post-Newtonian approximation. According to the theory of reference systems, the gravitational fields of these massive bodies are expressed ... More
The CO5BOLD Analysis ToolJan 08 2013The interactive IDL-based CO5BOLD Analysis Tool (CAT) was developed to facilitate an easy and quick analysis of numerical simulation data produced with the 2D/3D radiation magnetohydrodynamics code CO5BOLD. The basic mode of operation is the display and ... More
Predictions from Microscopic Models on Particle Correlations at RHICDec 17 2003We review the recent developments on microscopic transport calculations for two-particle correlations at low relative momenta in ultrarelativistic heavy ion collisions at RHIC.
Light-propagation in the gravitational field of moving quadrupolesMay 16 2011A simplified formula for light-deflection in the quadrupole field of moving massive bodies has been obtained in [1,2,3], which will be applied for Gaia data reduction. So far, in Gaia data reduction it has been assumed that the positions of the giant ... More
HBT interferometry and the parton-hadron phase transitionFeb 25 2002Mar 11 2002We discuss predictions for the pion and kaon interferometry measurements in relativistic heavy ion collisions at SPS and RHIC energies. In particular, we confront relativistic transport model calculations that include explicitly a first-order phase transition ... More
Dichotomy Results for Fixed-Point Existence Problems for Boolean Dynamical SystemsJan 24 2008Dec 01 2008A complete classification of the computational complexity of the fixed-point existence problem for boolean dynamical systems, i.e., finite discrete dynamical systems over the domain {0, 1}, is presented. For function classes F and graph classes G, an ... More
Effective Field Theory of Gravity: Leading Quantum Gravitational Corrections to Newtons and Coulombs LawAug 13 2007Jun 19 2008In this paper we consider general relativity and its combination with scalar quantum electrodynamics (QED) as an effective quantum field theory at energies well below the Planck scale. This enables us to compute the one-loop quantum corrections to the ... More
Sudakov Resummation for Electroproduction of Heavy QuarksMay 19 1998The leading and next-to-leading threshold logarithms of the QCD corrections to electroproduction of heavy quarks in single-particle inclusive kinematics are resummed to all orders in perturbation theory. The resummed cross-section is used to derive the ... More
Semidefinite programming bounds for Lee codesOct 11 2018For $q,n,d \in \mathbb{N}$, let $A_q^L(n,d)$ denote the maximum cardinality of a code $C \subseteq \mathbb{Z}_q^n$ with minimum Lee distance at least $d$, where $\mathbb{Z}_q$ denotes the cyclic group of order $q$. We consider a semidefinite programming ... More
Undecidable classical properties of observersJun 30 2005A property of a system is called actual, if the observation of the test that pertains to that property, yields an affirmation with certainty. We formalize the act of observation by assuming that the outcome correlates with the state of the observed system ... More
Minimisation of Deterministic Parity and Buchi Automata and Relative Minimisation of Deterministic Finite AutomataJul 08 2010Mar 14 2011In this report we study the problem of minimising deterministic automata over finite and infinite words. Deterministic finite automata are the simplest devices to recognise regular languages, and deterministic Buchi, Co-Buchi, and parity automata play ... More
Isomorphisms and Fusion Rules of Orthogonal Free Quantum Groups and their ComplexificationsJun 15 2010May 18 2011We show that all orthogonal free quantum groups are isomorphic to variants of the free orthogonal Wang algebra, the hyperoctahedral quantum group or the quantum permutation group. We also obtain a description of their free complexification. In particular ... More
Improved upper bound on A(18,8)Dec 07 2016Mar 03 2017For nonnegative integers $n$ and $d$, let $A(n,d)$ be the maximum cardinality of a binary code of length $n$ and minimum distance at least $d$. We consider a slight sharpening of the semidefinite programming bound of Gijswijt, Mittelmann and Schrijver, ... More
Cocompact amenable closed subgroups: weakly inequivalent representations in the left-regular representationOct 21 2015Jan 21 2016We show that if $H \leq G$ is a closed amenable and cocompact subgroup of a unimodular locally compact group, then the reduced group C*-algebra of $G$ is not simple. Equivalently, there are unitary representations of $G$ that are weakly contained in the ... More
On the classification of free Bogoljubov crossed product von Neumann algebras by the integersDec 13 2012We consider crossed product von Neumann algebras arising from free Bogoljubov actions of the integers. We describe several presentations of them as amalgamated free products and cocycle crossed products and give a criterion for factoriality. A number ... More
Electron spin filter and polarizer in a standing light waveApr 21 2016Oct 21 2016We demonstrate the theoretical feasibility of spin-dependent diffraction and spin-polarization of an electron in two counter-propagating, circular polarized laser beams in a relativistic quantum simulation. Our proposal realizes the Stern-Gerlach experiment ... More
A generalized lens equation for light deflection in weak gravitational fieldsMay 18 2011A generalized lens equation for weak gravitational fields in Schwarzschild metric and valid for finite distances of source and observer from the light deflecting body is suggested. The magnitude of neglected terms in the generalized lens equation is estimated ... More
On the determination of alpha_s from hadronic tau decays with contour-improved, fixed order and renormalon-chain perturbation theoryApr 11 2009Jun 11 2009One of the largest theoretical uncertainties assigned to the strong coupling constant alpha_s as determined from hadronic tau decays stems from the differences in the results for Fixed Order Perturbation Theory (FOPT), Contour Improved Perturbation Theory ... More
Proton and Neutron Irradiation Tests of Readout Electronics of the ATLAS Hadronic Endcap CalorimeterNov 16 2012The readout electronics of the ATLAS Hadronic Endcap Calorimeter will have to withstand the about ten times larger radiation environment of the future high-luminosity LHC (HL-LHC) compared to their design values. The GaAs ASIC which comprises the heart ... More
Determination of the Jet Energy ScaleJun 11 2007The uncertainty in jet energy scale is one of the dominating systematic errors for many measurements at hadron colliders - most notably for the measurement of the top-quark-mass, inclusive jet cross section measurements and last but not least for events ... More
On ground state phases of quantum spin systemsAug 26 2012In this short note, I review some recent results about gapped ground state phases of quantum spin systems and discuss the notion of topological order.
News on Strangeness at Ultrarelativistic Energies - Review of Microscopic ModelsDec 18 2003We review recent developments in the field of microscopic transport model calculations for ultrarelativistic heavy ion collisions. In particular, we focus on the strangeness production, for example, the phi-meson and its role as a messenger of the early ... More
New nonbinary code bounds based on a parity argumentJun 16 2016For $q,n,d \in \mathbb{N}$, let $A_q(n,d)$ be the maximum size of a code $C \subseteq [q]^n$ with minimum distance at least $d$. We give a parity argument that yields the new upper bounds $A_5(8,6)\leq 65$, $A_4(11,8)\leq 60$ and $A_3(16,11)\leq 29$. ... More
Partially Asymmetric Exclusion Process with Open BoundariesMay 25 1994Exclusive diffusion on a one-dimensional lattice is studied. In the model particles hop stochastically into both directions with different rates. At the ends of the lattice particles are injected and removed. The exact stationary probability measure is ... More
Improved upper bound on A(18,8)Dec 07 2016For nonnegative integers $n$ and $d$, let $A(n,d)$ be the maximum cardinality of a binary code of length $n$ and minimum distance at least $d$. We consider a slight sharpening of the semidefinite programming bound of Gijswijt, Mittelmann and Schrijver, ... More
A realistic device that simulates the non-local PR box without communicationApr 22 2005Apr 26 2005A black box with two input bits and two output bits is called a non-local PR box, if the XOR of the output bits equals the AND of the input bits. In a recent article, Cerf et al. show that Alice and Bob, using such a PR box, can effectively simulate entanglement ... More
A maximum principle for fractional diffusion processes with infinite horizonJun 15 2012Jun 28 2012We prove a maximum principle for the problem of optimal control for a fractional diffusion with infinite horizon. Further, we show existence of fractional backward stochastic differential equations on infinite horizon. We illustrate our findings with ... More
The nonparametric LAN expansion for discretely observed diffusionsFeb 06 2018Apr 15 2019Consider a scalar reflected diffusion $(X_t:t\geq 0)$, where the unknown drift function $b$ is modelled nonparametrically. We show that in the low frequency sampling case, when the sample consists of $(X_0,X_\Delta,...,X_{n\Delta})$ for some fixed sampling ... More
Penalty Interior-Point Method Fails to ConvergeOct 22 2003Equilibrium equations in the form of complementarity conditions often appear as constraints in optimization problems. Problems of this type are commonly referred to as mathematical programs with complementarity constraints (MPCCs). A popular method for ... More
Semidefinite programming bounds for Lee codesOct 11 2018Jun 09 2019For $q,n,d \in \mathbb{N}$, let $A_q^L(n,d)$ denote the maximum cardinality of a code $C \subseteq \mathbb{Z}_q^n$ with minimum Lee distance at least $d$, where $\mathbb{Z}_q$ denotes the cyclic group of order $q$. We consider a semidefinite programming ... More
Finite difference schemes for second order systems describing black holesApr 04 2006In the harmonic description of general relativity, the principle part of Einstein's equations reduces to 10 curved space wave equations for the componenets of the space-time metric. We present theorems regarding the stability of several evolution-boundary ... More
A Hydrodynamic Model of Movement of a Contact Line Over a Curved WallMay 21 2019The conventional no-slip boundary condition leads to a non-integrable stress singularity at a contact line. This is a main challenge in numerical simulations of two-phase flows with moving contact lines. We derive a two-dimensional hydrodynamic model ... More
Surface Waves in Almost Incompressible Elastic MaterialsSep 16 2013A recent study shows that the classical theory concerning accuracy and points per wavelength is not valid for surface waves in almost incompressible elastic materials. The grid size must instead be proportional to $(\frac{\mu}{\lambda})^{(1/p)}$ to achieve ... More
On the Success Probability of Decoding (Partial) Unit Memory CodesMay 24 2017In this paper, we derive analytic expressions for the success probability of decoding (Partial) Unit Memory codes in memoryless channels. An applications of this result is that these codes outperform individual block codes in certain channels.
Effective theories for liquid crystals and the Maier-Saupe phase transitionAug 20 2015We discuss effective theories for thermotropic nematic liquid crystals. In the first part of this article, we rigorously carry out two physically different scaling limits as the number of particles $N\to\infty$, which we call the mean-field and the Gross-Pitaevskii ... More