Results for "Søren Schmidt"

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Improved Orientation Sampling for Indexing Diffraction Patterns of Polycrystalline MaterialsJul 25 2017Oct 10 2017Orientation mapping is a widely used technique for revealing the microstructure of a polycrystalline sample. The crystalline orientation at each point in the sample is determined by analysis of the diffraction pattern, a process known as pattern indexing. ... More
On connected Lie groups and the Approximation PropertyMar 16 2016Recently, a complete characterization of connected Lie groups with the Approximation Property was given. The proof used of the newly introduced property (T*). We present here a short proof of the same result avoiding the use of property (T*). Using property ... More
Weak amenability and simply connected Lie groupsMay 05 2015Following an approach of Ozawa, we show that several semidirect products are not weakly amenable. As a consequence, we are able to characterize the simply connected Lie groups that are weakly amenable.
Two dimensional QCD is a string theoryAug 25 1994This text, written as dissertation within the M.Sc. course in particle theory at the Centre for Particle Theory, University of Durham, during the academic year 1993/94, reviews two articles by D.Gross and by D.Gross and W.Taylor which interpret the 1/N- ... More
Robust Structural Identification via Polyhedral Template MatchingMar 16 2016Apr 18 2016Successful scientific applications of large-scale molecular dynamics often rely on automated methods for identifying the local crystalline structure of condensed phases. Many existing methods for structural identification, such as Common Neighbour Analysis, ... More
Electron transport across a metal-organic interfaceJun 12 2013We simulate the electron transport across the Au(111)-pentacene interface using non-equilibrium Green's functions and density-functional theory (NEGF-DFT), and calculate the bias-dependent electron transmission. We find that the electrical contact resistance ... More
A Schur multiplier characterization of coarse embeddabilityMay 06 2015We give a contractive Schur multiplier characterization of locally compact groups coarsely embeddable into Hilbert spaces. Consequently, all locally compact groups whose weak Haagerup constant is 1 embed coarsely into Hilbert spaces, and hence the Baum-Connes ... More
First principles study of pentacene on Au(111)Aug 05 2013We investigate the atomic and electronic structure of a single layer of pentacene on the Au(111) surface using density functional theory. To find the candidate structures we strain match the pentacene crystal geometry with the Au(111) surface, in this ... More
Solid-state quantum optics with quantum dots in photonic nanostructuresNov 30 2012Quantum nanophotonics has become a new research frontier where quantum optics is combined with nanophotonics in order to enhance and control the interaction between strongly confined light and quantum emitters. Such progress provides a promising pathway ... More
Pointwise estimates on derivatives of Coulombic wave functions and their electron densitiesMar 09 2018We prove a priori bounds for all derivatives of non-relativistic Coulombic eigenfunctions, involving negative powers of the distance to the singularities of the many-body potential. We use these to derive bounds for all derivatives of the corresponding ... More
Role of the first coordination shell in determining the equilibrium structure and dynamics of simple liquidsJun 09 2011Aug 04 2011The traditional view that the physical properties of a simple liquid are determined primarily by its repulsive forces was recently challenged by Berthier and Tarjus, who showed that in some cases ignoring the attractions leads to large errors in the dynamics ... More
A uniqueness theorem for higher order anharmonic oscillatorsSep 09 2013Sep 10 2013We study for $\alpha\in\R$, $k \in {\mathbb N} \setminus \{0\}$ the family of self-adjoint operators \[ -\frac{d^2}{dt^2}+\Bigl(\frac{t^{k+1}}{k+1}-\alpha\Bigr)^2 \] in $L^2(\R)$ and show that if $k$ is even then $\alpha=0$ gives the unique minimum of ... More
The electron densities of pseudorelativistic eigenfunctions are smooth away from the nucleiNov 27 2008We consider a pseudorelativistic model of atoms and molecules, where the kinetic energy of the electrons is given by $\sqrt{p^2+m^2}-m$. In this model the eigenfunctions are generally not even bounded, however, we prove that the corresponding one-electron ... More
Mapping the local density of optical states of a photonic crystal with single quantum dotsJun 29 2011We use single self-assembled InGaAs quantum dots as internal probes to map the local density of optical states of photonic crystal membranes. The employed technique separates contributions from non-radiative recombination and spin-flip processes by properly ... More
Automorphisms of Cuntz-Krieger algebrasSep 04 2013We prove that the natural homomorphism from Kirchberg's ideal-related KK-theory, KKE(e, e'), with one specified ideal, into Hom_{\Lambda} (\underline{K}_{E} (e), \underline{K}_{E} (e')) is an isomorphism for all extensions e and e' of separable, nuclear ... More
Nonparametric Modeling of Dynamic Functional Connectivity in fMRI DataJan 04 2016Jun 08 2016Dynamic functional connectivity (FC) has in recent years become a topic of interest in the neuroimaging community. Several models and methods exist for both functional magnetic resonance imaging (fMRI) and electroencephalography (EEG), and the results ... More
Classification of irreversible and reversible Pimsner operator algebrasJul 02 2019Since their inception in the 30's by von Neumann, operator algebras have been used in shedding light in many mathematical theories. Classification results for self-adjoint and non-self-adjoint operator algebras manifest this approach, but a clear connection ... More
Towards representation stability for the second homology of the Torelli groupJan 30 2011Feb 02 2011We show for g > 6 that the second homology group of the Torelli group of a surface of genus g and 1 boundary component is generated as an Sp(2g,Z)-module by the image under the stabilization map of the second homology group of the Torelli group of a surface ... More
Ideal related K-theory with coefficientsOct 09 2012In this paper, we define an invariant, which we believe should be the substitute for total K-theory in the case when there is one distinguished ideal. Moreover, some diagrams relating the new groups to the ordinary K-groups with coefficients are constructed. ... More
Polarimetric Neutron Tomography of Magnetic Fields: Uniqueness of Solution and ReconstructionMar 25 2019Mar 27 2019We consider the problem of determination of a magnetic field from three dimensional polarimetric neutron tomography data. We see that this is an example of a non-Abelian ray transform and that the problem has a globally unique solution for smooth magnetic ... More
An accumulator model for primes and targets with independent response activation rates: Basic equations for average response timesApr 23 2018Apr 24 2018In response priming tasks, speeded responses are performed toward target stimuli preceded by prime stimuli. Responses are slower and error rates are higher when prime and target are assigned to different responses, compared to assignment to the same response, ... More
Convolutional LSTM Networks for Subcellular Localization of ProteinsMar 06 2015Machine learning is widely used to analyze biological sequence data. Non-sequential models such as SVMs or feed-forward neural networks are often used although they have no natural way of handling sequences of varying length. Recurrent neural networks ... More
Hashing for statistics over k-partitionsNov 26 2014Feb 15 2016In this paper we analyze a hash function for $k$-partitioning a set into bins, obtaining strong concentration bounds for standard algorithms combining statistics from each bin. This generic method was originally introduced by Flajolet and Martin~[FOCS'83] ... More
Third derivative of the one-electron density at the nucleusJul 04 2006We study electron densities of eigenfunctions of atomic Schroedinger operators. We prove the existence of rho~'''(0), the third derivative of the spherically averaged atomic density rho~ at the nucleus. For eigenfunctions with corresponding eigenvalue ... More
Probabilistic PARAFAC2Jun 21 2018The PARAFAC2 is a multimodal factor analysis model suitable for analyzing multi-way data when one of the modes has incomparable observation units, for example because of differences in signal sampling or batch sizes. A fully probabilistic treatment of ... More
Laue three dimensional neutron diffractionFeb 08 2019This article presents a measurement technique and data analysis tool to perform 3D grain distribution mapping and indexing of oligocrystalline samples using neutrons: Laue three-dimensional neutron diffraction (Laue3DND). The approach builds on forward ... More
Nucleation and droplet growth from supersaturated vapor at temperatures below the triple point temperatureApr 23 2016In 1897 Ostwald formulated his step rule for formation of the most stable crystal state for a system with crystal polymorphism. The rule describes the irreversible way a system converts to the crystal with lowest free energy. But in fact the irreversible ... More
Geometric classification of graph $C^*$-algebras over finite graphsApr 19 2016We address the classification problem for graph $C^*$-algebras of finite graphs (finitely many edges and vertices), containing the class of Cuntz-Krieger algebras as a prominent special case. Contrasting earlier work, we do not assume that the graphs ... More
Groups whose Fourier algebra and Rajchman algebra coincideSep 09 2016We study locally compact groups for which the Fourier algebra coincides with the Rajchman algebra. In particular, we show that there exist uncountably many non-compact groups with this property. Generalizing a result of Hewitt and Zuckerman, we show that ... More
On the Hardness of Partially Dynamic Graph Problems and Connections to DiameterFeb 22 2016May 03 2016Conditional lower bounds for dynamic graph problems has received a great deal of attention in recent years. While many results are now known for the fully-dynamic case and such bounds often imply worst-case bounds for the partially dynamic setting, it ... More
Only Bayes should learn a manifold (on the estimation of differential geometric structure from data)Jun 13 2018Jun 14 2018We investigate learning of the differential geometric structure of a data manifold embedded in a high-dimensional Euclidean space. We first analyze kernel-based algorithms and show that under the usual regularizations, non-probabilistic methods cannot ... More
Coulomb potentials and Taylor expansions in Time-Dependent Density Functional TheoryMar 07 2016Jun 29 2016We investigate when Taylor expansions can be used to prove the Runge-Gross Theorem, which is at the foundation of Time-Dependent Density Functional Theory (TDDFT). We start with a general analysis of the conditions for the Runge-Gross argument, especially ... More
Recurrent Spatial Transformer NetworksSep 17 2015We integrate the recently proposed spatial transformer network (SPN) [Jaderberg et. al 2015] into a recurrent neural network (RNN) to form an RNN-SPN model. We use the RNN-SPN to classify digits in cluttered MNIST sequences. The proposed model achieves ... More
Sequential Neural Models with Stochastic LayersMay 24 2016How can we efficiently propagate uncertainty in a latent state representation with recurrent neural networks? This paper introduces stochastic recurrent neural networks which glue a deterministic recurrent neural network and a state space model together ... More
Young Cool Stars Divided on the Issue of RotationNov 09 2008We present the results of a combination of new stellar rotation periods and extensive information about membership in the young open clusters M35 and M34. The observations show that late-type members of both clusters divide into two distinct groups, each ... More
A Prerequisite for LifeMay 22 2019The complex physicochemical structures and chemical reactions in living organism have some common features: (1) The life processes take place in the cytosol in the cells, which, from a physicochemical point of view is an emulsion of biomolecules in a ... More
Sparse Signal Reconstruction with Multiple Side Information using Adaptive Weights for Multiview SourcesMay 22 2016This work considers reconstructing a target signal in a context of distributed sparse sources. We propose an efficient reconstruction algorithm with the aid of other given sources as multiple side information (SI). The proposed algorithm takes advantage ... More
Network Communication with operators in Dedekind Finite and Stably Finite RingsJul 05 2015Messages in communication networks often are considered as "discrete" taking values in some finite alphabet (e.g. a finite field). However, if we want to consider for example communication based on analogue signals, we will have to consider messages that ... More
Dynamics of homogeneous nucleationOct 05 2015The classical nucleation theory for homogeneous nucleation is formulated as a theory for a density fluctuation in a supersaturated gas at a given temperature. But Molecular Dynamics simulations reveal that it is small cold clusters which initiates the ... More
The complete classification of unital graph $C^*$-algebras: Geometric and strongNov 22 2016We provide a complete classification of the class of unital graph $C^*$-algebras - prominently containing the full family of Cuntz-Krieger algebras - showing that Morita equivalence in this case is determined by ordered, filtered $K$-theory. The classification ... More
Geometric classification of unital graph C*-algebras of real rank zeroMay 25 2015Jul 08 2015We generalize the classification result of Restorff on Cuntz-Krieger algebras to cover all unital graph C*-algebras with real rank zero, showing that Morita equivalence in this case is determined by ordered, filtered K-theory as conjectured by three of ... More
Invariance of the Cuntz spliceFeb 11 2016Feb 12 2016We show that the Cuntz splice induces stably isomorphic graph $C^*$-algebras.
Real analyticity of solutions to Schrödinger equations involving fractional LaplaciansSep 18 2012Nov 06 2013We prove analyticity of solutions in $\mathbb{R}^{n}$, $n\ge1$, to certain nonlocal linear Schr\"odinger equations with analytic potentials.
Real analyticity away from the nucleus of pseudorelativistic Hartree-Fock orbitalsMar 25 2011Nov 04 2011We prove that the Hartree--Fock orbitals of pseudorelativistic atoms, that is, atoms where the kinetic energy of the electrons is given by the pseudorelativistic operator sqrt{-Delta+1}-1, are real analytic away from the origin. As a consequence, the ... More
Invisible stimuli, implicit thresholds: Why invisibility judgments cannot be interpreted in isolationJun 04 2013May 22 2014Some studies of unconscious cognition rely on judgments of participants stating that they have "not seen" the critical stimulus (e.g., in a masked-priming experiment). Trials in which participants gave "not-seen" judgments are then treated as those where ... More
On the applicability of the level set method beyond the flamelet regime in thermonuclear supernova simulationsJan 15 2007In thermonuclear supernovae, intermediate mass elements are mostly produced by distributed burning provided that a deflagration to detonation transition does not set in. Apart from the two-dimensional study by Roepke & Hillebrandt (2005), very little ... More
Spectroscopic Measurements Using the H1 and ZEUS DetectorsJun 08 2005Results on spectroscopy from the H1 and ZEUS collaborations are presented. The main focus is to search for baryon states which could be interpreted as pentaquarks. This includes states decaying to K^0_sp and K^0_s\bar{p}, \Xi\pi and D*p. In addition an ... More
Coarse homology of leavesNov 11 2014We investigate the coarse homology of leaves in foliations of compact manifolds. This is motivated by the observation that the non-leaves constructed by Schweitzer and by Zeghib all have non-finitely generated coarse homology. This led us to ask whether ... More
Localized spectral asymptotics for boundary value problems and correlation effects in the free Fermi gas in general domainsJun 07 2010We rigorously derive explicit formulae for the pair correlation function of the ground state of the free Fermi gas in the thermodynamic limit for general geometries of the macroscopic regions occupied by the particles and arbitrary dimension. As a consequence ... More
Counting rational points and lower bounds for Galois orbitsFeb 06 2018Feb 13 2018In this article we present a new method to obtain polynomial lower bounds for Galois orbits of torsion points of one dimensional group varieties.
Transverse Target Spin asymmetries in exclusive $ρ^0$ muoproductionNov 06 2013Generalized Parton Distributions (GPDs) provide a dynamical picture of the nucleon. The exclusive production of $\rho^0$ mesons on a transversely polarised target is sensitive to the nucleon helicity-flip GPDs $E$ which are related to the total angular ... More
Physics of Nuclear AntishadowingNov 14 2005Shadowing and antishadowing of the electromagnetic nuclear structure functions are produced by the coherence of multiscattering quark nuclear processes. This picture leads to substantially different antishadowing for charged and neutral current processes, ... More
Characterization of highly anisotropic three-dimensionally nanostructured surfacesAug 13 2013Generalized ellipsometry, a non-destructive optical characterization technique, is employed to determine geometrical structure parameters and anisotropic dielectric properties of highly spatially coherent three-dimensionally nanostructured thin films ... More
Auslander Regularity of p-adic Distribution AlgebrasMar 15 2007Oct 01 2012Given a compact p-adic Lie group we show that its distribution algebra is Frechet-Stein with Auslander regular Banach algebras. As an application, we show that nonzero coadmissible modules coming from smooth or, more general, U(g)-finite representations ... More
Cosmological Simulations of Normal-Branch Braneworld GravityOct 01 2009Aug 01 2018We introduce a cosmological model based on the normal branch of DGP braneworld gravity with a smooth dark energy component on the brane. The expansion history in this model is identical to LambdaCDM, thus evading all geometric constraints on the DGP cross-over ... More
Canonical Lifts of Cycle Classes of SectionsSep 13 2016Jun 06 2017We present the construction of canonical lifts of $\ell$-adic cycle classes of sections of $p$-adic projective anabelian curves to the cohomology of arbitrary proper, regular, flat models. This answers a question of Esnault and Wittenberg.
Sections, Homotopy Rational Points and Reductions of CurvesJul 14 2015Sep 01 2016We study unramified sections of the fundamental group sequence of smooth projective curves of genus $\geq 2$ over $p$-adic fields together with an integral model. We are particularly interested in the induced specialized sections of the special fibre ... More
Homotopy Rational Points of Brauer-Severi VarietiesMar 27 2015We study homotopy rational points of Brauer-Severi varieties over fields of characteristic zero. We are particularly interested if a Brauer-Severi variety admitting a homotopy rational point splits. The analogue statement turns out to be true for open ... More
Functorial Approach to Graph and Hypergraph TheoryJul 04 2019We provide a new approach to categorical graph and hypergraph theory by using categorical syntax and semantics. For each monoid $M$ and action on a set $X$, there is an associated presheaf topos of $(X,M)$-graphs where each object can be interpreted as ... More
Picard groups in $p$-adic Fourier theoryMar 27 2009Jun 25 2013Let $L$ be a proper finite extension of the field of $p$-adic numbers and let $o\subset L$ be its integers, viewed as an abelian locally $L$-analytic group. Let $\hat{o}$ be the rigid analytic group variety parametrizing the locally analytic characters ... More
Rank two sheaves with maximal third Chern character in three-dimensional projective spaceNov 29 2018We give a complete classification of semistable rank two sheaves on three-dimensional projective space with maximal third Chern character. This implies an explicit description of their moduli spaces. As an open subset they contain rank two reflexive sheaves ... More
Elicitation of ambiguous beliefs with mixing betsFeb 20 2019I consider the elicitation of ambiguous beliefs about an event. I introduce a mechanism that allows to identify an interval of probabilities (representing ambiguity perception) for several classes of ambiguity averse preferences. The agent reveals her ... More
Bridgeland Stability on Threefolds - Some Wall CrossingsSep 15 2015Following up on the construction of Bridgeland stability condition on $\mathbb{P}^3$ by Macr\`i, we compute first examples of wall crossing behaviour. In particular, for Hilbert schemes of curves such as twisted cubics or complete intersections of the ... More
Counterexample to the Generalized Bogomolov-Gieseker Inequality for ThreefoldsFeb 16 2016We give a counterexample to the generalized Bogomolov-Gieseker inequality for threefolds conjectured by Bayer, Macr\`i and Toda using the blow up of a point over three dimensional projective space.
On locally analytic Beilinson-Bernstein localization and the canonical dimensionAug 07 2011Jun 25 2013Let G be a connected split reductive group over a p-adic field. In the first part of the paper we prove, under certain assumptions on G and the prime p, a localization theorem of Beilinson-Bernstein type for admissible locally analytic representations ... More
Recurrence of cocycles and stationary random walksAug 09 2006We survey distributional properties of $\mathbb{R}^d$-valued cocycles of finite measure preserving ergodic transformations (or, equivalently, of stationary random walks in $\mathbb{R}^d$) which determine recurrence or transience.
Sources of false positives and false negatives in the STATCHECK algorithm: Reply to Nuijten et al. (2016)Oct 04 2016Nov 16 2016STATCHECK is an R algorithm designed to scan papers automatically for inconsistencies between test statistics and their associated p values (Nuijten et al., 2016). The goal of this comment is to point out an important and well-documented flaw in this ... More
The Numerical Simulation of TurbulenceDec 06 2007In this contribution, I give an overview of the various approaches toward the numerical modelling of turbulence, particularly, in the interstellar medium. The discussion is placed in a physical context, i. e. computational problems are motivated from ... More
Arithmetic gravity and Yang-Mills theory: An approach to adelic physics via algebraic spacesSep 21 2008This work is a dissertation thesis written at the WWU Muenster (Germany), supervised by Prof. Dr. Raimar Wulkenhaar. We present an approach to adelic physics based on the language of algebraic spaces. Relative algebraic spaces X over a base S are considered ... More
The Petersen graph has no quantum symmetryJan 09 2018Jan 17 2018In 2007, Banica and Bichon asked whether the well-known Petersen graph has quantum symmetry. In this article, we show that the Petersen graph has no quantum symmetry, i.e. the quantum automorphism group of the Petersen graph is its usual automorphism ... More
Lattice QCD at Finite DensityOct 24 2006Oct 31 2006I discuss different approaches to finite density lattice QCD. In particular, I focus on the structure of the phase diagram and discuss attempts to determine the location of the critical end-point. Recent results on the transiton line as function of the ... More
The strange degrees of freedom in QCD at high temperatureDec 17 2013We discuss recent results on fluctuations of conserved charges, and their approach to the hadron resonance gas at temperatures below the chiral crossover (Tc) as well as to a gas of free quarks at very high temperatures. We will focus on the strange degrees ... More
QCD thermodynamics at zero and non-zero densityJan 23 2007We present recent results on thermodynamics of QCD with almost physical light quark masses and a physical strange quark mass value. These calculations have been performed with an improved staggerd action especially designed for finite temperature lattice ... More
The QCD phase diagram for small chemical potentialsOct 18 2002We compute derivatives of thermodynamic quantities with respect to $\mu$, at $\mu=0$ for 2 and 3 flavors of degenerate quark masses. This allows us to estimate the phase transition line in the $T,\mu$ plane and quantify the influence of a non vanishing ... More
Celestial mechanics in Kerr spacetimeFeb 26 2002The dynamical parameters conventionally used to specify the orbit of a test particle in Kerr spacetime are the energy $E$, the axial component of the angular momentum, $L_{z}$, and Carter's constant $Q$. These parameters are obtained by solving the Hamilton-Jacobi ... More
Quantum Algorithms for many-to-one Functions to Solve the Regulator and the Principal Ideal ProblemDec 24 2009We propose new quantum algorithms to solve the regulator and the principal ideal problem in a real-quadratic number field. We improve the algorithms proposed by Hallgren by using two different techniques. The first improvement is the usage of a period ... More
On the relation between 2 and infty in Galois cohomology of number fieldsAug 24 2000We remove the assumption "let p be odd or k totally imaginary" from several well-known theorems in Galois cohomology of number fields. For example, we show that the Galois group of the maximal extension of a number field k which is unramified outside ... More
Tame coverings of arithmetic schemesMay 31 2000We extend the notion of a tame covering of a pair (X,D) where X is a regular scheme and D is a normal crossing divisor (cf. SGA1), to pairs (X,Y) where X is an arbitrary scheme and Y is a closed subset in X. We show that the abelianized tame fundamental ... More
On pro-p fundamental groups of marked arithmetic curvesJun 11 2008Jan 16 2009Let k be a global field, p an odd prime number different from char(k) and S, T disjoint, finite sets of primes of k. Let G_S^T(k)(p)=Gal(k_S^T(p)|k) be the Galois group of the maximal p-extension of k which is unramified outside S and completely split ... More
Über Pro-p-Fundamentalgruppen markierter arithmetischer KurvenJun 04 2008Jan 16 2009Let k be a global field, p an odd prime number different from char(k) and S, T disjoint, finite sets of primes of k. Let G_S^T(k)(p)=Gal(k_S^T(p)|k) be the Galois group of the maximal p-extension of k which is unramified outside S and completely split ... More
On the quantum symmetry of distance-transitive graphsJun 15 2019In this article, we study quantum automorphism groups of distance-transitive graphs. We show that the odd graphs, the Hamming graphs $H(n,3)$, the Johnson graphs $J(n,2)$ and the Kneser graphs $K(n,2)$ do not have quantum symmetry. We also give a table ... More
The effect of relative velocity and density perturbations between baryons and dark matter on the clustering of galaxiesFeb 29 2016Aug 24 2016Pre-recombination acoustic oscillations induce non-adiabatic perturbations between baryons and dark matter, corresponding to a constant relative-density $\delta_{bc}$ and decaying relative-velocity perturbation $\vec{v}_{bc}$. Due to their significant ... More
Towards a self-consistent halo model for the nonlinear large-scale structureNov 06 2015Feb 17 2016The halo model is a theoretically and empirically well-motivated framework for predicting the statistics of the nonlinear matter distribution in the Universe. However, current incarnations of the halo model suffer from two major deficiencies: $(i)$ they ... More
Monodromic Dark EnergySep 05 2017Oct 06 2017Since the discovery of the accelerated expansion of the Universe, the constraints on the equation of state $w_\text{DE}$ of dark energy, the stress-energy component responsible for the acceleration, have tightened significantly. These constraints generally ... More
On a Direct Description of Pseudorelativistic Nelson HamiltoniansOct 08 2018Abstract interior-boundary conditions (IBC's) allow for the direct description of the domain and the action of Hamiltonians for a certain class of ultraviolet-divergent models in Quantum Field Theory. The method was recently applied to models where nonrelativistic ... More
Ground states of the 2D sticky disc model: fine properties and $N^{3/4}$ law for the deviation from the asymptotic Wulff shapeFeb 26 2013Mar 05 2013We investigate ground state configurations for a general finite number $N$ of particles of the Heitmann-Radin sticky disc pair potential model in two dimensions. Exact energy minimizers are shown to exhibit large microscopic fluctuations about the asymptotic ... More
Introduction to Machine ProtectionAug 08 2016Protection of accelerator equipment is as old as accelerator technology and was for many years related to high-power equipment. Examples are the protection of powering equipment from overheating (magnets, power converters, high-current cables), of superconducting ... More
Machine Protection and Interlock Systems for Circular Machines - Example for LHCAug 10 2016This paper introduces the protection of circular particle accelerators from accidental beam losses. Already the energy stored in the beams for accelerators such as the TEVATRON at Fermilab and Super Proton Synchrotron (SPS) at CERN could cause serious ... More
Counting rational points and lower bounds for Galois orbitsFeb 06 2018In this article we present a new method to obtain polynomial lower bounds for Galois orbits of torsion points of one dimensional group varieties.
Hadronic fluctuations and correlations at nonzero chemical potentialOct 22 2009We present a lattice study of fluctuations and correlations among the conserved charges baryon number and strangeness in (2+1)-flavor QCD. The lattice calculations are based on a Taylor expansion of the pressure. Results are presented at zero and nonzero ... More
Lattice Simulations with Chemical PotentialAug 31 2004After giving an overview of recently invented methods for simulating lattice QCD at small mu/T, we discuss some results for bulk thermodynamic quantities of QCD matter coming from those methods. We focus on the transition line and the critical endpoint ... More
Local Grand Unification in the Heterotic LandscapeJun 30 2009Sep 03 2009We consider the possibility that the unification of the electroweak interactions and the strong force arises from string theory, at energies significantly lower than the string scale. As a tool, an effective grand unified field theory in six dimensions ... More
The Weight in EnumerationDec 02 2016In our setting enumeration amounts to generate all solutions of a problem instance without duplicates. We address the problem of enumerating the models of B-formulae. A B-formula is a propositional formula whose connectives are taken from a fixed set ... More
Gauge-Higgs Unification from the Heterotic StringAug 31 2007We present a 6D orbifold model on $T^2/\Z2$ which emerges as intermediate step in the compactification of the heterotic string to the supersymmetric standard model in four dimensions. It has $\SU6$ gauge symmetry in the bulk and two pairs of inequivalent ... More
An Array AlgebraDec 29 2008This is a proposal of an algebra which aims at distributed array processing. The focus lies on re-arranging and distributing array data, which may be multi-dimensional. The context of the work is scientific processing; thus, the core science operations ... More
Circular sets of prime numbers and p-extension of the rationalsApr 26 2005Feb 05 2006Let p be an odd prime number and let S be a finite set of prime numbers congruent to 1 modulo p. We prove that the group G_S(Q)(p) has cohomological dimension 2 if the linking diagram attached to S and p satisfies a certain technical condition, and we ... More
Large Eddy Simulations of Supersonic TurbulenceOct 01 2009Based on ideas by Woodward et al., a subgrid scale model that is applicable to highly compressible turbulence is presented. Applying the subgrid scale model in large eddy simulations of forced supersonic turbulence, the bottleneck effect is largely reduced ... More
How much two-photon exchange is needed to resolve the proton form factor discrepancy?Jul 17 2019Background: One possible explanation for the proton form factor discrepancy is a contribution to the elastic electron-proton cross section from hard two-photon exchange (TPE), a typically neglected radiative correction. Hard TPE cannot be calculated in ... More
The 3/5-conjecture for weakly $S(K_{1,3})$-free forestsJul 10 2015The $3/5$-conjecture for the domination game states that the game domination numbers of an isolate-free graph $G$ on $n$ vertices are bounded as follows: $\gamma_g(G)\leq \frac{3n}5 $ and $\gamma_g'(G)\leq \frac{3n+2}5 $. Recent progress have been done ... More
Quantum automorphisms of folded cube graphsOct 26 2018We show that the quantum automorphism group of the Clebsch graph is $SO_5^{-1}$. This answers a question by Banica, Bichon and Collins from 2007. More general for odd $n$, the quantum automorphism group of the folded $n$-cube graph is $SO_n^{-1}$. Furthermore, ... More