Results for "Søren Schmidt"

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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
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
Bayesian parameter inference from continuously monitored quantum systemsDec 22 2012We review the introduction of likelihood functions and Fisher information in classical estimation theory, and we show how they can be defined in a very similar manner within quantum measurement theory. We show that the stochastic master equations describing ... More
Tight Hardness Results for Distance and Centrality Problems in Constant Degree GraphsSep 27 2016Finding important nodes in a graph and measuring their importance is a fundamental problem in the analysis of social networks, transportation networks, biological systems, etc. Among popular such metrics are graph centrality, betweenness centrality (BC), ... More
Discretization error for a two-sided reflected Lévy processAug 13 2017Jan 03 2018An obvious way to simulate a L\'evy process $X$ is to sample its increments over time $1/n$, thus constructing an approximating random walk $X^{(n)}$. This paper considers the error of such approximation after the two-sided reflection map is applied, ... More
The Equivariant Cobordism CategoryMay 31 2018For a finite group $G$, we define an equivariant cobordism category $\mathcal{C}_d^G$. Objects of the category are $(d-1)$-dimensional closed smooth $G$-manifolds and morphisms are smooth $d$-dimensional equivariant cobordisms. We identify the homotopy ... More
On exceedance times for some processes with dependent incrementsMay 25 2012Mar 07 2013Let ${Z_n}_{n\ge 0}$ be a random walk with a negative drift and i.i.d. increments with heavy-tailed distribution and let $M=\sup_{n\ge 0}Z_n$ be its supremum. Asmussen & Kl{\"u}ppelberg (1996) considered the behavior of the random walk given that $M>x$, ... 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
Regular Variation in a Fixed-Point Problem for Single- and Multiclass Branching Processes and QueuesSep 15 2017Feb 14 2018Tail asymptotics of the solution $R$ to a fixpoint problem of type $R =_{st} Q + \sum_1^N R_m$ is derived under heavy-tailed conditions allowing both dependence between $Q$ and $N$ and the tails to be of the same order of magnitude. Similar results are ... More
Protein Secondary Structure Prediction with Long Short Term Memory NetworksDec 25 2014Jan 04 2015Prediction of protein secondary structure from the amino acid sequence is a classical bioinformatics problem. Common methods use feed forward neural networks or SVMs combined with a sliding window, as these models does not naturally handle sequential ... More
Relative and center-of-mass motion in the attractive Bose-Hubbard modelFeb 16 2012Mar 22 2012We present first-principle numerical calculations for few particle solutions of the attractive Bose-Hubbard model with periodic boundary conditions. We show that the low-energy many-body states found by numerical diagonalization can be written as translational ... More
Combinatorial representationsSep 06 2011This paper introduces combinatorial representations, which generalise the notion of linear representations of matroids. We show that any family of subsets of the same cardinality has a combinatorial representation via matrices. We then prove that any ... More
Time inhomogeneity in longest gap and longest run problemsOct 02 2015Consider an inhomogeneous Poisson process and let $D$ be the first of its epochs which is followed by a gap of size $\ell>0$. We establish a criterion for $D<\infty$ a.s., as well as for $D$ being long-tailed and short-tailed, and obtain logarithmic tail ... 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
Time-of-Flight Three Dimensional Neutron Diffraction in Transmission Mode for Mapping Crystal Grain StructuresApr 20 2017The physical properties of polycrystalline materials depend on their microstructure, which is the nano-to-centimeter-scale arrangement of phases and defects in their interior. Such microstructure depends on the shape, crystallographic phase and orientation, ... 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
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
Auxiliary Deep Generative ModelsFeb 17 2016Jun 16 2016Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. ... 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
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
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
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
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
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.
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
Compressive Time Delay Estimation Using InterpolationJun 11 2013Time delay estimation has long been an active area of research. In this work, we show that compressive sensing with interpolation may be used to achieve good estimation precision while lowering the sampling frequency. We propose an Interpolating Band-Excluded ... 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
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
How (In)accurate Are Demand Forecasts in Public Works Projects? The Case of TransportationMar 20 2013This article presents results from the first statistically significant study of traffic forecasts in transportation infrastructure projects. The sample used is the largest of its kind, covering 210 projects in 14 nations worth US$59 billion. The study ... More
Underestimating Costs in Public Works Projects: Error or Lie?Mar 06 2013This article presents results from the first statistically significant study of cost escalation in transportation infrastructure projects. Based on a sample of 258 transportation infrastructure projects worth US$90 billion and representing different project ... 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
Improved initial guess for minimum energy path calculationsJun 05 2014A method is presented for generating a good initial guess of a transition path between given initial and final states of a system without evaluation of the energy. An objective function surface is constructed using an interpolation of pairwise distances ... More
Online Decomposition of Compressive Streaming Data Using $n$-$\ell_1$ Cluster-Weighted MinimizationFeb 08 2018We consider a decomposition method for compressive streaming data in the context of online compressive Robust Principle Component Analysis (RPCA). The proposed decomposition solves an $n$-$\ell_1$ cluster-weighted minimization to decompose a sequence ... 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
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
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
A Two Stage CVT / Eikonal Convection Mesh Deformation Approach for Large Nodal DeformationsNov 27 2014A two step mesh deformation approach for large nodal deformations, typically arising from non-parametric shape optimization, fluid-structure interaction or computer graphics, is considered. Two major difficulties, collapsed cells and an undesirable parameterization, ... 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.
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
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
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.
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
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
On the K(π,1)-property for rings of integers in the mixed caseJan 14 2008We investigate the Galois group G_S(p) of the maximal p-extension unramified outside a finite set S of primes of a number field in the (mixed) case, when there are primes dividing p inside and outside S. We show that the cohomology of G_S(p) is "often" ... More
Gamma-Ray Burst Luminosity Functions Based On a Newly Discovered Correlation Between Peak Spectral Energy and V/V_maxMay 18 2009Aug 06 2009We have discovered a correlation between the observed peak spectral energy E_pk,obs and the average Euclidean value of V/V_max of gamma-ray bursts (GRBs). We present the evidence for the correlation in the GUSBAD catalog and use it to derive the luminosity ... More
Are Durations of Weak Gamma-Ray Bursts Reliable?Aug 16 2005Simulations in the GUSBAD Catalog of gamma-ray bursts suggest that the apparent duration of a burst decreases as its amplitude is decreased. We see no evidence for this effect in the BATSE catalog. We show that for a burst at the detection limit, the ... More
Rosenfeld functional for non-additive hard spheresJul 01 2004The fundamental measure density functional theory for hard spheres is generalized to binary mixtures of arbitrary positive and moderate negative non-additivity between unlike components. In bulk the theory predicts fluid-fluid phase separation into phases ... More
Gamma-Ray Bursts Detected From BATSE DISCLA DataAug 17 1999We have searched for gamma-ray bursts (GRB) in the BATSE DISCLA data covering the period TJD 8365-10528. We employ an algorithm that uses the background both before and after the onset of the burst, and that requires an excess of at least 5 sigma over ... More
Statics and dynamics of inhomogeneous liquids via the internal-energy functionalOct 20 2011We give a variational formulation of classical statistical mechanics where the one-body density and the local entropy distribution constitute the trial fields. Using Levy's constrained search method it is shown that the grand potential is a functional ... 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
AntihydrogenJan 31 1997CERN announced in January 1996 the detection of the first eleven atoms of antimatter ever produced. The experiment was based on a method proposed earlier by S. Brodsky, C. Munger and I. Schmidt, and which furthermore predicted exactly the number of atoms ... 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
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
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
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
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 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
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
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
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
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
Quark and Gluon Sivers FunctionsNov 14 2005The physics of hadron single transverse spin asymmetries is discussed. Possible measurements of both the quark and gluon Sivers functions are proposed.
Shadowing and Antishadowing in Neutrino Deep Inelastic ScatteringJul 07 2005The coherence of multiscattering quark nuclear processes leads to shadowing and antishadowing of the electromagnetic nuclear structure functions in agreement with measurements. This picture leads to substantially different antishadowing for charged and ... More
Non-Gaussian Halo Bias Beyond the Squeezed LimitApr 05 2013Jun 13 2013Primordial non-Gaussianity, in particular the coupling of modes with widely different wavelengths, can have a strong impact on the large-scale clustering of tracers through a scale-dependent bias with respect to matter. We demonstrate that the standard ... More
Analytic vectors in continuous p-adic representationsNov 13 2007Oct 01 2012Given a compact p-adic Lie group G over a finite unramified extension L/Q_p let G_0 be the product over all Galois conjugates of G. We construct an exact and faithful functor from admissible G-Banach space representations to admissible locally L-analytic ... More
On the Birational Geometry of Schubert VarietiesAug 27 2012Mar 05 2015We classify all Q-factorializations of (co)minuscule Schubert varieties by using their Mori dream space structure. As a corollary we obtain a description of all IH-small resolutions of (co)minuscule Schubert varieties generalizing results of Perrin. We ... More
Three Dimensional Polarimetric Neutron Tomography of Magnetic FieldsApr 17 2017Feb 02 2018Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions ... More
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
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
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.
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
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
Ring extensions invariant under group actionMar 26 2014May 07 2014Let $G$ be a subgroup of the automorphism group of a commutative ring with identity $T$. Let $R$ be a subring of $T$ such that $R$ is invariant under the action by $G$. We show $R^G\subset T^G$ is a minimal ring extension whenever $R\subset T$ is a minimal ... More
Relative K-theory and class field theory for arithmetic surfacesApr 29 2002In this paper we extend the unramified class field theory for arithmetic surfaces of K. Kato and S. Saito to the relative case. Let X be a regular proper arithmetic surface and let Y be the support of divisor on X. Let CH_0(X,Y) denote the relative Chow ... 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
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
The Massless Nelson Hamiltonian and its DomainJan 17 2019In the theory of point interactions, one is given a formal expression for a quantum mechanical Hamiltonian. The interaction terms of the Hamiltonian are singular: they can not be rigorously defined as a perturbation (in the operator or form sense) of ... 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
Large-scale Velocities and Primordial Non-GaussianityMay 21 2010Jun 01 2010We study the peculiar velocities of density peaks in the presence of primordial non-Gaussianity. Rare, high density peaks in the initial density field can be identified with tracers such as galaxies and clusters in the evolved matter distribution. The ... More
Self-Consistent Cosmological Simulations of DGP Braneworld GravityMay 06 2009Sep 16 2009We perform cosmological N-body simulations of the Dvali-Gabadadze-Porrati braneworld model, by solving the full non-linear equations of motion for the scalar degree of freedom in this model, the brane bending mode. While coupling universally to matter, ... More
Weak Lensing Probes of Modified GravityMay 30 2008Jul 14 2008We study the effect of modifications to General Relativity on large scale weak lensing observables. In particular, we consider three modified gravity scenarios: f(R) gravity, the DGP model, and TeVeS theory. Weak lensing is sensitive to the growth of ... More
Dynamical Masses in Modified GravityMar 01 2010Mar 11 2010Differences in masses inferred from dynamics, such as velocity dispersions or X-rays, and those inferred from lensing are a generic prediction of modified gravity theories. Viable models however must include some non-linear mechanism to restore General ... More
Cosmological Simulations of Normal-Branch Braneworld GravityOct 01 2009Nov 30 2009We 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
Sources of false positives and false negatives in the STATCHECK algorithm: Reply to Nuijten et al. (2015)Oct 04 2016Oct 10 2016STATCHECK is an R algorithm designed to scan papers automatically for inconsistencies between test statistics and their associated p values (Nuijten et al., 2015). The goal of this comment is to point out an important and well-documented flaw in this ... More
Sources of false positives and false negatives in the STATCHECK algorithm: Reply to Nuijten et al. (2016)Oct 04 2016Nov 15 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
Large Eddy Simulations in AstrophysicsApr 09 2014In this review, the methodology of large eddy simulations (LES) is introduced and applications in astrophysics are discussed. As theoretical framework, the scale decomposition of the dynamical equations for neutral fluids by means of spatial filtering ... More
A generalized Bogomolov-Gieseker inequality for the smooth quadric threefoldSep 17 2013May 07 2014We prove a generalized Bogomolov-Gieseker inequality as conjectured by Bayer, Macr\`i and Toda for the smooth quadric threefold. This implies the existence of a family of Bridgeland stability conditions.
Topological Entropy Bounds for Switched Linear Systems with Lie StructureOct 09 2016In this thesis, we provide an initial investigation into bounds for topological entropy of switched linear systems. Entropy measures, roughly, the information needed to describe the behavior of a system with finite precision on finite time horizons, in ... More
Representations of toral automorphismsAug 13 2015Aug 24 2015This survey gives an account of an algebraic construction of symbolic covers and representations of ergodic automorphisms of compact abelian groups, initiated by A.M. Vershik around 1992 for hyperbolic automorphisms of finite-dimensional tori. The key ... More
Auslander-Reiten theory for simply connected differential graded algebrasJan 04 2008Peter Jorgensen introduced the Auslander-Reiten quiver of a simply connected Poincare duality space. He showed that its components are of the form ZA_infty and that the Auslander-Reiten quiver of a d-dimensional sphere consists of d-1 such components. ... More
On the infinite particle limit in Lagrangian dynamics and convergence of optimal transportation meshfree methodsJan 15 2013We consider Lagrangian systems in the limit of infinitely many particles. It is shown that the corresponding discrete action functionals Gamma-converge to a continuum action functional acting on probability measures of particle trajectories. Also the ... More
A Griffith-Euler-Bernoulli theory for thin brittle beams derived from nonlinear models in variational fracture mechanicsFeb 24 2016We study a planar thin brittle beam subject to elastic deformations and cracks described in terms of a nonlinear Griffith energy functional acting on $SBV$ deformations of the beam. In particular we consider the case in which elastic bulk contributions ... More
Rings of integers of type $K(π,1)$May 23 2007Nov 14 2007We investigate the Galois group $G_S(p)$ of the maximal $p$-extension unramified outside a finite $S$ of primes of a number field in the (tame) case, when no prime dividing $p$ is in $S$. We show that the cohomology of $G_S(p)$ is 'often' isomorphic to ... More
Tame class field theory for arithmetic schemesOct 12 2004We extend the unramified class field theory for arithmetic schemes of K. Kato and S. Saito to the tame case. Let $X$ be a regular proper arithmetic scheme and let $D$ be a divisor on $X$ whose vertical irreducible components are normal schemes. Theorem: ... More
Proceedings of the 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection (JAS 2014), Newport Beach, CA, USA, 5-14 Nov 2014Aug 11 2016Many particle accelerators operate with very high beam power and very high energy stored in particle beams as well as in magnet systems. In the future, the beam power in high intensity accelerators will further increase. The protection of the accelerator ... More