Searching Arxiv, refresh for possibly better results.

Results for "Stefan Sorge"

total 9316took 0.15s
On Kernelization and Approximation for the Vector Connectivity ProblemOct 31 2014Jun 23 2015In the Vector Connectivity problem we are given an undirected graph $G=(V,E)$, a demand function $\phi\colon V\to\{0,\ldots,d\}$, and an integer $k$. The question is whether there exists a set $S$ of at most $k$ vertices such that every vertex $v\in V\setminus ... More
The Minimum Feasible Tileset problemSep 30 2014We consider the Minimum Feasible Tileset problem: Given a set of symbols and subsets of these symbols (scenarios), find a smallest possible number of pairs of symbols (tiles) such that each scenario can be formed by selecting at most one symbol from each ... More
Smoothing of the slowly extracted coasting beam from a synchrotronApr 19 2019Slow extraction of beam from synchrotrons or storage rings as required by many fixed target experiments is performed by controlled excitation and feeding of a structural lattice resonance. Due to the sensitive nature of this resonant extraction process, ... More
The Parameterized Complexity of the Minimum Shared Edges ProblemFeb 04 2016We study the NP-complete Minimum Shared Edges (MSE) problem. Given an undirected graph, a source and a sink vertex, and two integers p and k, the question is whether there are p paths in the graph connecting the source with the sink and sharing at most ... More
$Ψ'/Ψ$ ratio in Nucleus-Nucleus Collisions : a Measure for the Chiral Symmetry Restoration Temperature ?May 15 1997We argue that a decrease of the chiral scalar meson mass is responsible for re-creation of $\Psi'$ from $J/\Psi$ in ultrarelativistic nucleus-nucleus collisions. This causes the charmonium yields to freeze out at temperatures close to the chiral symmetry ... More
Valuation of path-dependent American options using a Monte Carlo approachJan 12 1998It is shown how to obtain accurate values for American options using Monte Carlo simulation. The main feature of the novel algorithm consists of tracking the boundary between exercise and hold regions via optimization of a certain payoff function. We ... More
Collective flow and QCD phase transitionJun 16 1999Jun 23 1999In the first part I discuss the sensitivity of collective matter expansion in ultrarelativistic heavy-ion collisions to the transition between quark and hadronic matter (physics of the softest point of the Equation of State). A kink in the centrality ... More
Assessing the Computational Complexity of Multi-Layer Subgraph DetectionApr 26 2016Multi-layer graphs consist of several graphs (layers) over the same vertex set. They are motivated by real-world problems where entities (vertices) are associated via multiple types of relationships (edges in different layers). We chart the border of ... More
``Day 1'' Physics at RHIC: Predictions from RQMDMay 04 1999I discuss predictions based on the transport theoretical approach ``relativistic quantum molecular dynamics''. They can be tested rather soon by the upcoming experiments at the Relativistic Heavy Ion Collider at BNL (RHIC). Here I focus on the question ... More
Highly Sensitive Centrality Dependence of Elliptic Flow -- A Novel Signature of the Phase Transition in QCDDec 21 1998Jun 24 1999Elliptic flow of the hot, dense system which has been created in nucleus-nucleus collisions develops as a response to the initial azimuthal asymmetry of the reaction region. Here it is suggested that the magnitude of this response shows a ``kinky'' dependence ... More
Remnants of Initial Anisotropic High Energy Density Domains in Nucleus-Nucleus CollisionsNov 03 1998Dec 19 1998Anisotropic high energy density domains may be formed at early stages of ultrarelativistic heavy ion collisions, e.g. due to phase transition dynamics or non-equilibrium phenomena like (mini-)jets. Here we investigate hadronic observables resulting from ... More
Resource Adaptive Agents in Interactive Theorem ProvingJan 23 2009We introduce a resource adaptive agent mechanism which supports the user in interactive theorem proving. The mechanism uses a two layered architecture of agent societies to suggest appropriate commands together with possible command argument instantiations. ... More
The Minimum Shared Edges Problem on Planar GraphsFeb 03 2016We study the Minimum Shared Edges problem introduced by Omran et al. [Journal of Combinatorial Optimization, 2015] on planar graphs: Planar MSE asks, given a planar graph G = (V,E), two distinct vertices s,t in V , and two integers p, k, whether there ... More
sec-cs: Getting the Most out of Untrusted Cloud StorageJun 10 2016We present sec-cs, a hash-table-like data structure for file contents on untrusted storage that is both secure and storage-efficient. We achieve authenticity and confidentiality with zero storage overhead using deterministic authenticated encryption. ... More
Weak Limit of the 3-State Quantum Walk on the LineApr 04 2014May 21 2014We revisit the one dimensional discrete time quantum walk with 3 states and the Grover coin. We derive analytic expressions for observed the localization, an long time approximation for the probability density function (PDF). We also connect the time ... More
Streaming KernelizationMay 06 2014Kernelization is a formalization of preprocessing for combinatorially hard problems. We modify the standard definition for kernelization, which allows any polynomial-time algorithm for the preprocessing, by requiring instead that the preprocessing runs ... More
On the commutability of homogenization and linearization in finite elasticityNov 16 2010May 16 2011We study non-convex elastic energy functionals associated to (spatially) periodic, frame indifferent energy densities with a single non-degenerate energy well at SO(n). Under the assumption that the energy density admits a quadratic Taylor expansion at ... More
The midpoint between dipole and parton showersJun 16 2015Sep 19 2015We present a new parton-shower algorithm. Borrowing from the basic ideas of dipole cascades, the evolution variable is judiciously chosen as the transverse momentum in the soft limit. This leads to a very simple analytic structure of the evolution. A ... More
Interactive Natural Language Acquisition in a Multi-modal Recurrent Neural ArchitectureMar 24 2017Feb 07 2018For the complex human brain that enables us to communicate in natural language, we gathered good understandings of principles underlying language acquisition and processing, knowledge about socio-cultural conditions, and insights about activity patterns ... More
Reliability of regulatory networks and its evolutionMay 27 2008The problem of reliability of the dynamics in biological regulatory networks is studied in the framework of a generalized Boolean network model with continuous timing and noise. Using well-known artificial genetic networks such as the repressilator, we ... More
Reliability of genetic networks is evolvableJul 10 2007Control of the living cell functions with remarkable reliability despite the stochastic nature of the underlying molecular networks -- a property presumably optimized by biological evolution. We here ask to what extent the property of a stochastic dynamical ... More
On Semigroups of Two-Dimensional Upper-Triangular Integer MatricesMay 13 2019We analyze algorithmic problems in finitely generated semigroups of two-dimensional upper-triangular integer matrices. These semigroup problems are tightly connected with problems about compositions of affine functions over one variable. Building on a ... More
The H-Covariant Strong Picard GroupoidSep 08 2004Apr 25 2005The notion of H-covariant strong Morita equivalence is introduced for *-algebras over C = R(i) with an ordered ring R which are equipped with a *-action of a Hopf *-algebra H. This defines a corresponding H-covariant strong Picard groupoid which encodes ... More
A shortcut to (sun)flowers: Kernels in logarithmic space or linear timeApr 30 2015We investigate whether kernelization results can be obtained if we restrict kernelization algorithms to run in logarithmic space. This restriction for kernelization is motivated by the question of what results are attainable for preprocessing via simple ... More
Evidence of early multi-strange hadron freeze-out in high energy nuclear collisionsApr 18 1998Recently reported transverse momentum distributions of strange hadrons produced in Pb(158AGeV) on Pb collisions and corresponding results from the relativistic quantum molecular dynamics (RQMD) approach are examined. We argue that the experimental observations ... More
Finite-Size Corrections for Ground States of Edwards-Anderson Spin GlassesOct 28 2011May 30 2012Extensive computations of ground state energies of the Edwards-Anderson spin glass on bond-diluted, hypercubic lattices are conducted in dimensions d=3,..,7. Results are presented for bond-densities exactly at the percolation threshold, p=p_c, and deep ... More
Superstability of the yeast cell cycle dynamics: Ensuring causality in the presence of biochemical stochasticityMay 05 2006Gene regulatory dynamics is governed by molecular processes and therefore exhibits an inherent stochasticity. However, for the survival of an organism it is a strict necessity that this intrinsic noise does not prevent robust functioning of the system. ... More
Subsampling Extremes: From Block Maxima to Smooth Tail EstimationApr 02 2012Oct 19 2014We study a new estimator for the tail index of a distribution in the Frechet domain of attraction that arises naturally by computing subsample maxima. This estimator is equivalent to taking a U-statistic over a Hill estimator with two order statistics. ... More
Progress in modeling magnetic white dwarfsFeb 04 2003First satisfactory fits to the flux spectrum and circular polarization of the DAP Grw +70 8247 are presented, as well as a first model of the DBP GD 229 with consistent helium line data.
The combinatorial multitude of fatty acids can be described by Fibonacci numbersMar 28 2013The famous series of Fibonacci numbers is defined by a recursive equation saying that each number is the sum of its two predecessors, with the initial condition that the first two numbers are equal to unity. Here, we show that the numbers of fatty acids ... More
Beyond the Second Generation of Laser-Interferometric Gravitational Wave ObservatoriesNov 27 2011This article gives an overview of potential upgrades of second generation gravitational wave detectors and the required key technologies to improve the limiting noise sources. In addition the baseline design of the Einstein Telescope, a European third ... More
Centralizers in 3-manifold groupsMay 10 2012Using the Geometrization Theorem we prove a result on centralizers in fundamental groups of 3-manifolds. This result had been obtained by Jaco and Shalen and by Johannson using different techniques.
$L^2$--eta--invariants and their approximation by unitary eta--invariantsMay 28 2003Cochran, Orr and Teichner introduced $L^2$--eta--invariants to detect highly non--trivial examples of non slice knots. Using a recent theorem by L\"uck and Schick we show that their metabelian $L^2$--eta--invariants can be viewed as the limit of finite ... More
A note on the growth of Betti numbers and ranks of 3-manifold groupsJan 17 2013Apr 18 2013Let N be an irreducible, compact 3-manifold with empty or toroidal boundary which is not a closed graph manifold. Using recent work of Agol, Kahn-Markovic and Przytycki-Wise we will show that pi_1(N) admits a cofinal filtration with `fast' growth of Betti ... More
Sharp L^1 Poincare inequalities correspond to optimal hypersurface cutsSep 24 2013Jun 19 2015Let $\Omega \subset \mathbb{R}^n$ be a convex. If $u: \Omega \rightarrow \mathbb{R}$ has mean 0, then we have the classical Poincar\'{e} inequality $$ \|u \|_{L^p} \leq c_p \mbox{diam}(\Omega) \| \nabla u \|_{L^p}$$ with sharp constants $c_2 = 1/\pi$ ... More
Lower bounds on nodal sets of eigenfunctions via the heat flowJan 15 2013Jul 03 2015We study the size of nodal sets of Laplacian eigenfunctions on compact Riemannian manifolds without boundary and recover the currently optimal lower bound by comparing the heat flow of the eigenfunction with that of an artifically constructed diffusion ... More
Extremal Optimization: Heuristics via Co-Evolutionary AvalanchesJun 23 2000An introduction to Extremal Optimization written for the Computer Simulation Column in ``Computing in Science and Engineering'' (CISE).
Extremal Optimization for Sherrington-Kirkpatrick Spin GlassesJul 06 2004Mar 24 2005Extremal Optimization (EO), a new local search heuristic, is used to approximate ground states of the mean-field spin glass model introduced by Sherrington and Kirkpatrick. The implementation extends the applicability of EO to systems with highly connected ... More
Mode-by-mode hydrodynamics: ideas and conceptsJan 10 2014The main ideas, technical concepts and perspectives for a mode resolved description of the hydrodynamical regime of relativistic heavy ion collisions are discussed. A background-fluctuation splitting and a Bessel-Fourier expansion for the fluctuating ... More
GPU-based visualization of domain-coloured algebraic Riemann surfacesJul 16 2015Nov 10 2015We examine an algorithm for the visualization of domain-coloured Riemann surfaces of plane algebraic curves. The approach faithfully reproduces the topology and the holomorphic structure of the Riemann surface. We discuss how the algorithm can be implemented ... More
Hopf algebras and Dyson-Schwinger equationsJun 30 2015Jan 28 2016In these lectures I discuss Hopf algebras and Dyson-Schwinger equations. The lectures start with an introduction to Hopf algebras, followed by a review where Hopf algebras occur in particles physics. The final part of these lectures is devoted to the ... More
On the solutions of the scattering equationsFeb 11 2014Mar 13 2014This paper addresses the question, whether the solutions of the scattering equations in four space-time dimensions can be expressed as rational functions of the momentum twistor variables. This is the case for $n\le5$ external particles. For general $n$ ... More
NNLO predictions for event shapes and jet rates in electron-positron annihilationJan 08 2010The strong coupling constant is a fundamental parameter of nature. It can be extracted from experiments measuring three-jet events in electron-positron annihilation. For this extraction precise theoretical calculations for jet rates and event shapes are ... More
The infrared structure of e+ e- --> 3 jets at NNLO reloadedApr 07 2009Jun 16 2009This paper gives detailed information on the structure of the infrared singularities for the process e+ e- --> 3 jets at next-to-next-to-leading order in perturbation theory. Particular emphasis is put on singularities associated to soft gluons. The knowledge ... More
Symbolic Expansion of Transcendental FunctionsJan 04 2002Feb 25 2002Higher transcendental function occur frequently in the calculation of Feynman integrals in quantum field theory. Their expansion in a small parameter is a non-trivial task. We report on a computer program which allows the systematic expansion of certain ... More
The forward-backward asymmetry at NNLO revisitedSep 04 2006Nov 16 2006I reconsider the forward-backward asymmetry for flavoured quarks in electron-positron annihilation. I suggest an infrared-safe definition of this observable, such that the asymmetry may be computed in perturbative QCD with massless quarks. With this definition, ... More
Infrared finite cross sections at NNLOJun 29 2004I discuss methods for the cancellation of infrared divergences at NNLO.
A general algorithm to generate unweighted events for next-to-leading order calculations in electron-positron annihilationJun 14 2001Sep 27 2001Given a next-to-leading order calculation, we show how to set up a computer program, which generates a sequence of unweighted momentum configurations, each configuration containing either n or n+1 four-vectors, such that for any infrared safe observable ... More
The status of gamma-ray astronomyApr 20 2012Gamma-ray studies are an essential tool in our search for the origin of cosmic rays. Instruments like the Fermi-LAT, H.E.S.S., MAGIC and VERITAS have revolutionized our understanding of the high energy Universe. This paper describes the status of the ... More
Exploring Level Statistics from Quantum Chaos to Localization with the Autocorrelation Function of Spectral DeterminantsJun 30 1998The autocorrelation function of spectral determinants (ASD) is used to characterize the discrete spectrum of a phase coherent quasi- 1- dimensional, disordered wire as a function of its length L in a finite, weak magnetic field. An analytical function ... More
Sneutrino Hybrid InflationAug 23 2006We review the scenario of sneutrino hybrid inflation, where one of the singlet sneutrinos, the superpartners of the right-handed neutrinos, plays the role of the inflaton. In a minimal model of sneutrino hybrid inflation, the spectral index is given by ... More
Models for Neutrino Masses and MixingsJan 23 2013We review recent developments towards models for neutrino masses and mixings.
Statistical Analysis of Multiwavelength Light curvesJul 05 2012Since its launch in 2008 the Fermi Large Area Telescope provides regular monitoring of a large sample of gamma-ray sources on time scales from hours to years. Together with observations at other wavelengths it is now possible to study variability and ... More
Measurement of Dijet Production in Diffractive Deep-Inelastic Scattering at HERAAug 19 2015The production of dijets is measured in diffractive deep-inelastic scattering at HERA. The data were recorded with the H1 detector at DESY in the years 2003-2007. Diffractive events are selected by requiring a gap in the rapidity distribution of the hadronic ... More
Lower estimates of random unconditional constants of Walsh-Paley martingales with values in banach spacesFeb 28 1992For a Banach space X we define RUMD_n(X) to be the infimum of all c>0 such that (AVE_{\epsilon_k =\pm 1} || \sum_1^n epsilon_k (M_k - M_{k-1} )||_{L_2^X}^2 )^{1/2} <= c || M_n ||_{L_2^X} holds for all Walsh-Paley martingales {M_k}_0^n subset L_2^X with ... More
Filling invariants at infinity and the Euclidean rank of Hadamard spacesDec 25 2005Jul 26 2006In this paper we study a homological version of the higher-dimensional divergence invariants defined by Brady and Farb. We show that they are quasi-isometry invariants in the class of proper cocompact Hadamard spaces in the sense of Alexandrov and that ... More
The bottomonium spectrum from lattice QCD with 2+1 flavors of domain wall fermionsMar 18 2009Apr 21 2009Recently, realistic lattice QCD calculations with 2+1 flavors of domain wall fermions and the Iwasaki gauge action have been performed by the RBC and UKQCD collaborations. Here, results for the bottomonium spectrum computed on their gauge configurations ... More
Scaling and Decoherence in the Out-of-Equilibrium Kondo ModelOct 13 2004Oct 26 2004We study the Kondo effect in quantum dots in an out-of-equilibrium state due to an applied dc-voltage bias. Using the method of infinitesimal unitary transformations (flow equations), we develop a perturbative scaling picture that naturally contains both ... More
Calculation of Massless Feynman Integrals using Harmonic SumsMay 19 2005Jul 10 2006A method for the evaluation of the epsilon expansion of multi-loop massless Feynman integrals is introduced. This method is based on the Gegenbauer polynomial technique and the expansion of the Gamma function in terms of harmonic sums. Algorithms for ... More
Anisotropically Weighted and Nonholonomically Constrained Evolutions on ManifoldsSep 01 2016We present evolution equations for a family of paths that results from anisotropically weighting curve energies in non-linear statistics of manifold valued data. This situation arise when performing inference on data that have non-trivial covariance and ... More
Variance estimation for Brier Score decompositionMar 25 2013Jul 18 2013The Brier Score is a widely-used criterion to assess the quality of probabilistic predictions of binary events. The expectation value of the Brier Score can be decomposed into the sum of three components called reliability, resolution, and uncertainty ... More
Adiabatic limit interference effects for two energy level transition amplitudes and Nikitin - Umanskii formula studied by fundamental solution methodJul 18 2002Apr 04 2003A method of fundamental solutions has been used to study adiabatic transition amplitudes in two energy level systems for a class of Hamiltonians allowing some simplifications of Stokes graphs corresponding to such transitions. It has been shown that for ... More
The Schrödinger functional in QCDNov 28 1994The Schr\"odinger functional in Wilson's lattice QCD leads to a sensible classical continuum theory which can be taken as starting point for a perturbative analysis. In dimensional regularization, the saddle point expansion of the Schr\"odinger functional ... More
Properties of the renormalized quark mass in the Schrodinger functional with a non-vanishing background fieldNov 28 2001We compute the current quark mass in the Schrodinger functional with a non-vanishing background field at one loop order of perturbation theory. The results are used to obtain the critical mass at which the renormalized quark mass vanishes, and some lattice ... More
Combining optical spectroscopy and interferometryDec 13 2013Modern optical spectrographs and optical interferometers push the limits in the spectral and spatial regime, providing important new tools for the exploration of the universe. In this contribution I outline the complementary nature of spectroscopic & ... More
H-äquivariante Morita-Äquivalenz und DeformationsquantisierungApr 09 2010English abstract: This work contains of five chapters: The first one deals with Morita equivalence of star algebras. In particular star algebras which are equipped with a symmetry given by a Hopf (star-) algebra. In the second chapter we describe the ... More
Projective Wellorders and the Nonstationary IdealOct 13 2016We show that, under the assumption of the existence of $M_1^{\#}$, there exists a model on which the restricted nonstationary ideal $\hbox{NS} \upharpoonright A$ is $\aleph_2$-saturated, for $A$ a stationary co-stationary subset of $\omega_1$, while the ... More
Valuation Theory, Riemann Varieties and the Structure of integral PreschemesOct 25 2016In this work we show that the classical subject of general valuation theory and Zariski-Riemann varieties has a much wider scope than commutative algebra and desingularization theory. We construct and investigate birational projective limit objects appropriate ... More
On panel-regular ~A_2 latticesAug 25 2016We study lattices on ~A_2 buildings that preserve types, act regularly on each type of edge, and whose vertex stabilizers are cyclic. We show that several of their properties, such as their automorphism group and isomorphism class, can be determined from ... More
Fast Escape in Incompressible Vector FieldsMay 09 2016Swimmers caught in a rip current flowing away from the shore are advised to swim orthogonally to the current to escape it. We describe a mathematical principle in a similar spirit. More precisely, we consider flows $\gamma$ in the plane induced by incompressible ... More
The japanese closure of local noetherian ringsOct 27 2016Given a local noetherian ring $R$ whose formal completion is integral, we introduce and study the japanese closure $R^\text{jpn}$. Roughly speaking, this is the largest purely inseparable $R$-subalgebra inside the formal completion $\hat{R}$. It turns ... More
Well-distributed great circles on S^2Jul 13 2016Let $C_1, \dots, C_n$ denote the $1/n-$neighborhood of $n$ great circles on $\mathbb{S}^2$. We are interested in how much these areas have to overlap and prove the sharp bounds $$ \sum_{i, j = 1 \atop i \neq j}^{n}{|C_i \cap C_j|^s} \gtrsim_s \begin{cases} ... More
Localization of Quantum States and Landscape FunctionsOct 21 2015Eigenfunctions in inhomogeneous media can have strong localization properties. Filoche \& Mayboroda showed that the function $u$ solving $(-\Delta + V)u = 1$ controls the behavior of eigenfunctions $(-\Delta + V)\phi = \lambda\phi$ via the inequality ... More
Measurement of the strong coupling alpha_s from the 3-jet rate in e+e- annihilation using JADE dataJun 01 2012We describe a measurement of the strong coupling alpha_S(m_Z) from the 3-jet rate in hadronic final states of e+e- annihilation recorded with the JADE detector at centre-of-mass energies of 14 to 44 GeV. The jets are reconstructed with the Durham jet ... More
Studies of the 4-jet rate and of moments of event shape observables using JADE dataSep 06 2004Data from e+e- annihilation into hadrons collected by the JADE experiment at centre-of-mass energies between 14 and 44 GeV were used to study the 4-jet rate using the Durham algorithm as well as the first five moments of event shape observables. The data ... More
Fine-Tuning of the Cosmological Constant in Brane WorldsDec 05 2000Dec 14 2000We discuss how the fine-tuning of the cosmological constant enters brane world setups. After presenting the Randall Sundrum model as a prototype case, we focus on single brane models with curvature singularities which are separated from the brane in the ... More
A note on inflationary string cosmologyFeb 27 1998Apr 06 1998Cosmological solutions are obtained by continuation of black D-brane solutions into the region between the horizons. It is investigated whether one can find exponential expansion when probing the cosmology with D-branes. A unique configuration exhibiting ... More
Regulatory Medicine Against Financial Market Instability: What Helps And What Hurts?Nov 29 2010Nov 30 2010Do we know if a short selling ban or a Tobin Tax result in more stable asset prices? Or do they in fact make things worse? Just like medicine regulatory measures in financial markets aim at improving an already complex system. And just like medicine these ... More
Quantum Lower Bounds by Entropy NumbersNov 30 2006We use entropy numbers in combination with the polynomial method to derive a new general lower bound for the n-th minimal error in the quantum setting of information-based complexity. As an application, we improve some lower bounds on quantum approximation ... More
From Monte Carlo to Quantum ComputationDec 23 2001Quantum computing was so far mainly concerned with discrete problems. Recently, E. Novak and the author studied quantum algorithms for high dimensional integration and dealt with the question, which advantages quantum computing can bring over classical ... More
Quantum Summation with an Application to IntegrationMay 23 2001We study summation of sequences and integration in the quantum model of computation. We develop quantum algorithms for computing the mean of sequences which satisfy a p-summability condition and for integration of functions from Lebesgue spaces L_p([0,1]^d) ... More
A Bayesian Network Approach to Assess and Predict Software Quality Using Activity-Based Quality ModelsNov 30 2016Context: Software quality is a complex concept. Therefore, assessing and predicting it is still challenging in practice as well as in research. Activity-based quality models break down this complex concept into concrete definitions, more precisely facts ... More
Scrum for cyber-physical systems: a process proposalMar 20 2017Agile development processes and especially Scrum are changing the state of the practice in software development. Many companies in the classical IT sector have adopted them to successfully tackle various challenges from the rapidly changing environments ... More
A Bayesian Network Approach to Assess and Predict Software Quality Using Activity-Based Quality Models (Conference Version)Nov 30 2016Assessing and predicting the complex concept of software quality is still challenging in practice as well as research. Activity-based quality models break down this complex con- cept into more concrete definitions, more precisely facts about the system, ... More
Thirring's low-energy theorem and its generalizations in the electroweak Standard ModelApr 21 1997The radiative corrections to Compton scattering vanish in the low-energy limit in all orders of perturbation theory. This theorem, which is well-known for Abelian gauge theories, is proved in the electroweak Standard Model. Moreover, analogous theorems ... More
Electrostatic Interpretation of Zeros of Orthogonal PolynomialsApr 25 2018May 16 2018We study the differential equation $ - (p(x) y')' + q(x) y' = \lambda y,$ where $p(x)$ is a polynomial of degree at most 2 and $q(x)$ is a polynomial of degree at most 1. This includes the classical Jacobi polynomials, Hermite polynomials, Legendre polynomials, ... More
Quantitative Projections in the Sturm Oscillation TheoremApr 16 2018Apr 18 2018There is $c_{} > 0$ such that for all $f \in C[0,\pi]$ with at most $d-1$ roots inside $(0,\pi)$ $$ \sum_{1 \leq n \leq d}{ \left| \left\langle f, \sin\left( n x\right) \right\rangle \right|} \geq \kappa^{-\kappa^2 \log{\kappa}}\|f\|_{L^2} \qquad \mbox{where} ... More
Baryon chiral perturbation theoryDec 23 2011We provide a short introduction to the one-nucleon sector of chiral perturbation theory and address the issue of power counting and renormalization. We discuss the infrared regularization and the extended on-mass-shell scheme. Both allow for the inclusion ... More
Exotic hadrons from dynamical clustering of quarks in ultrarelativistic heavy ion collisionsNov 22 2004Results from a model study on the formation of exotic quark clusters at the hadronization stage of a heavy ion collision are presented. The dynamical quark molecular dynamics (qMD) model which is used is sketched, and results for exotica made of up to ... More
Non-Locality Without Counterfactual ReasoningMay 26 2015Jun 08 2015Non-local correlations are usually understood through the outcomes of alternative measurements (on two or more parts of a system) that cannot altogether actually be carried out in an experiment. Indeed, a joint input/output -- e.g., measurement-setting/outcome ... More
Kinematic Effects in Quarkonia ProductionAug 17 2000We investigate energy (momentum) distributions in J/Psi photoproduction and J/Psi production in B meson decay. In particular the upper endpoint region of the spectrum is examined where the effect of soft gluon emission from the ccbar pair becomes important. ... More
Hilbert scheme strata defined by bounding cohomologySep 06 2005Let Hilb^p be the Hilbert scheme parametrizing the closed subschemes of P^n with Hilbert polynomial p\in Q[t] over a field K of characteristic zero. By bounding below the cohomological Hilbert functions of the points of Hilb^p we define locally closed ... More
On the effect of multiplicative noise in a supercritical pitchfork bifurcationApr 09 2010The most important characteristic of {\em multiplicative noise} is that its effects of system's dynamics depends on the recent system's state. Consideration of multiplicative noise on self-referential systems including biological and economical systems ... More
On reduction maps and support problem in K-theory and abelian varietiesApr 11 2005In this paper we consider reduction maps $r_{v} : K_{2n+1}(F)/C_{F} \to K_{2n+1}(\kappa_{v})_{l}$ where $F$ is a number field and $C_{F}$ denotes the subgroup of $K_{2n+1}(F)$ generated by $l$-parts (for all primes $l$) of kernels of the Dwyer-Friedlander ... More
States and representations in deformation quantizationAug 17 2004In this review we discuss various aspects of representation theory in deformation quantization starting with a detailed introduction to the concepts of states as positive functionals and the GNS construction. But also Rieffel induction of representations ... More
The Picard groupoid in deformation quantizationDec 05 2003In this letter we give an overview on recent developments in representation theory of star product algebras. In particular, we relate the *-representation theory of *-algebras over rings C = R(i) with an ordered ring R and i^2 = -1 to the *-representation ... More
Points in the fppf topologyJul 21 2014Jan 26 2016Using methods from commutative algebra and topos-theory, we construct topos-theoretical points for the fppf topology of a scheme. These points are indexed by both a geometric point and a limit ordinal. The resulting stalks of the structure sheaf are what ... More
Convergence of Star Product: From Examples to a General FrameworkJan 31 2019We recall some of the fundamental achievements of formal deformation quantization to argue that one of the most important remaining problems is the question of convergence. Here we discuss different approaches found in the literature so far. The recent ... More
Fast multigrid solvers for conforming and non-conforming multi-patch Isogeometric AnalysisFeb 05 2019Apr 01 2019Isogeometric Analysis is a high-order discretization method for boundary value problems that uses a number of degrees of freedom which is as small as for a low-order method. Standard isogeometric discretizations require a global parameterization of the ... More
A first approach to the Galois group of chaotic chainsFeb 01 2019We explain in detail the definition, construction and generalisation of the Galois group of Chebyshev polynomials of high degree to the Galois group of chaotic chains. The calculations in this paper are performed for Chebyshev polynomials and chaotic ... More