Results for "Björn Alling"

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Structure and Bonding in Amorphous Cr1-xCx Nanocomposite Thin Films: X-ray Absorption Spectra and First-Principles CalculationNov 25 2016The local structure and chemical bonding in two-phase amorphous Cr$_{1-x}$C$_{x}$ nanocomposite thin films are investigated by Cr $K$-edge ($1s$) X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies ... More
The role of N defects in paramagnetic CrN at finite temperatures from first-principlesOct 20 2014Simulations of defects in paramagnetic materials at high temperature constitute a formidable challenge to solid state theory due to the interaction of magnetic disorder, vibrations, and structural relaxations. CrN is a material where these effects are ... More
Efficient and accurate determination of lattice-vacancy diffusion coefficients via non equilibrium ab initio molecular dynamicsSep 15 2015Feb 13 2016We revisit the color-diffusion algorithm [P. C. Aeberhard et al., Phys. Rev. Lett. 108, 095901 (2012)] in nonequilibrium ab initio molecular dynamics (NE-AIMD), and propose a simple efficient approach for the estimation of monovacancy jump rates in crystalline ... More
Anomalous phonon lifetime shortening in paramagnetic CrN caused by magneto-lattice coupling: A combined spin and ab initio molecular dynamics studyFeb 08 2018We study the mutual coupling of spin fluctuations and lattice vibrations in paramagnetic CrN by combining atomistic spin dynamics and ab initio molecular dynamics. The two degrees of freedom are dynamically coupled leading to non-adiabatic effects. Those ... More
Vibrational free energy and phase stability of paramagnetic and antiferromagnetic CrN from ab-initio molecular dynamicsMar 19 2014We present a theoretical first-principles method to calculate the free energy of a magnetic system in its high-temperature paramagnetic phase, including vibrational, electronic, and magnetic contributions. The method for calculating free energies is based ... More
Finite temperature elastic constants of paramagnetic materials within the disordered local moment picture from ab initio molecular dynamics calculationsApr 29 2016Jun 09 2016We present a theoretical scheme to calculate the elastic constants of magnetic materials in the high-temperature paramagnetic state. Our approach is based on a combination of disordered local moments picture and ab initio molecular dynamics (DLM-MD). ... More
Origin of the anomalous piezoelectric response in wurtzite Sc$_x$Al$_{1-x}$N alloysMar 17 2010The origin of the anomalous, 400% increase of the piezoelectric coefficient in Sc$_x$Al$_{1-x}$N alloys is revealed. Quantum mechanical calculations show that the effect is intrinsic. It comes from a strong change in the response of the internal atomic ... More
Poincaré inequalities and Newtonian Sobolev functions on noncomplete metric spacesMay 05 2017Let $X$ be a noncomplete metric space satisfying the usual (local) assumptions of a doubling property and a Poincar\'e inequality. We study extensions of Newtonian Sobolev functions to the completion $\widehat{X}$ of $X$ and use them to obtain several ... More
Anharmonicity changes the solid solubility of an alloy at high temperaturesMar 09 2015Sep 23 2015We have developed a method to accurately and efficiently determine the vibrational free energy as a function of temperature and volume for substitutional alloys from first principles. Taking Ti$_{1-x}$Al$_x$N alloy as a model system, we calculate the ... More
A uniqueness result for functions with zero fine gradient on quasiconnected and finely connected setsFeb 16 2018We show that every Sobolev function in $W^{1,p}_{\textrm{loc}}(U)$ on a $p$-quasiopen set $U \subset {\bf R}^n$ with a.e.-vanishing $p$-fine gradient is a.e.-constant if and only if $U$ is $p$-quasiconnected. To prove this we use the theory of Newtonian ... More
Obstacle and Dirichlet problems on arbitrary nonopen sets, and fine topologyAug 24 2012We study the double obstacle problem for p-harmonic functions on arbitrary bounded nonopen sets E in quite general metric spaces. The Dirichlet and single obstacle problems are included as special cases. We obtain Adams' criterion for the solubility of ... More
Functional Uniform Priors for Nonlinear ModellingOct 19 2011This paper considers the topic of finding prior distributions when a major component of the statistical model depends on a nonlinear function. Using results on how to construct uniform distributions in general metric spaces, we propose a prior distribution ... More
The Dirichlet problem for p-harmonic functions on the topologist's combApr 05 2013In this paper we study the Perron method for solving the p-harmonic Dirichlet problem on the topologist's comb. For functions which are bounded and continuous at the accessible points, we obtain invariance of the Perron solutions under arbitrary perturbations ... More
Embedded Markov chain approximations in Skorokhod topologiesSep 16 2014Jan 30 2018In order to approximate a continuous time stochastic process by discrete time Markov chains one has several options to embed the Markov chains into continuous time processes. On the one hand there is the Markov embedding, which uses exponential waiting ... More
Well-posedness and Stability of Linear Port-Hamiltonian Systems with Nonlinear Boundary FeedbackJun 09 2015Apr 25 2016Boundary feedback stabilisation of linear port-Hamiltonian systems on an interval is considered. Generation and stability results already known for linear feedback are extended to nonlinear dissipative feedback, both to static feedback control and dynamic ... More
Stabilization Bounds for Linear Finite Dynamical SystemsMar 31 2017A common problem to all applications of linear finite dynamical systems is analyzing the dynamics without enumerating every possible state transition. Of particular interest is the long term dynamical behaviour. In this paper, we study the number of iterations ... More
Well-posedness and Stability for Interconnection Structures of Port-Hamiltonian TypeOct 01 2018We consider networks of infinite-dimensional port-Hamiltonian systems $\mathfrak{S}_i$ on one-dimensional spatial domains. These subsystems of port-Hamiltonian type are interconnected via boundary control and observation and are allowed to be of distinct ... More
Local and semilocal Poincaré inequalities on metric spacesMar 02 2017Mar 09 2018We consider several local versions of the doubling condition and Poincar\'e inequalities on metric spaces. Our first result is that in proper connected spaces, the weakest local assumptions self-improve to semilocal ones, i.e. holding within every ball. ... More
Tensor products and sums of p-harmonic functions, quasiminimizers and p-admissible weightsJul 06 2017The tensor product of two p-harmonic functions is in general not p-harmonic, but we show that it is a quasiminimizer. More generally, we show that the tensor product of two quasiminimizers is a quasiminimizer. Similar results are also obtained for quasisuperminimizers ... More
The variational capacity with respect to nonopen sets in metric spacesOct 01 2012We pursue a systematic treatment of the variational capacity on metric spaces and give full proofs of its basic properties. A novelty is that we study it with respect to nonopen sets, which is important for Dirichlet and obstacle problems on nonopen sets, ... More
Radiative corrections to neutralino annihilation: Recent developmentsNov 30 2010Evaluating the relic density of dark matter is an interesting possibility to constrain the parameter space of new physics models. However, this calculation is affected by several sources of uncertainty. On the particle physics side, considerable progress ... More
Flavour Violation in GMSB Scenarios: Constraints and PhenomenologyOct 07 2008We present an extensive analysis of low-energy, electroweak precision, and cosmological constraints in the Minimal Supersymmetric Standard Model (MSSM) with Gauge-Mediated Supersymmetry Breaking (GMSB) and including the possibility of Non-Minimal Flavour ... More
Embedded Markov chain approximations in Skorokhod topologiesSep 16 2014In order to approximate a continuous time stochastic process by discrete time Markov chains one has several options to embed the Markov chains into continuous time processes. On the one hand there is the Markov embedding, which uses exponential waiting ... More
Skew Closed Structure of Gray-CategoriesOct 12 2016We define a skew-closed structure for Gray-categories extending the mapping space construction of the author.
Sharp exponents and a Wiener type condition for boundary regularity of quasiminimizersApr 30 2015We obtain a sufficient condition for boundary regularity of quasiminimizers of the p-energy integral in terms of a Wiener type sum of power type. The exponent in the sum is independent of the dimension and is explicitly expressed in terms of p and the ... More
Feller Evolution Systems: Generators and ApproximationMay 02 2013A time and space inhomogeneous Markov process is a Feller evolution process, if the corresponding evolution system on the continuous functions vanishing at infinity is strongly continuous. We discuss generators of such systems and show that under mild ... More
Mapping Spaces of Gray-CategoriesDec 03 2012Jan 14 2014We define a mapping space for Gray-enriched categories adapted to higher gauge theory. Our construction differs significantly from the canonical mapping space of enriched categories in that it is much less rigid. The two essential ingredients are a path ... More
Diffusive stability against nonlocalized perturbations of planar wave trains in reaction-diffusion systemsMar 26 2018Planar wave trains are traveling wave solutions whose wave profiles are periodic in one spatial direction and constant in the transverse direction. In this paper, we investigate the stability of planar wave trains in reaction-diffusion systems. We establish ... More
Periodic solutions for the N-vortex problem via a superposition principleAug 29 2017We examine the $N$-vortex problem on general domains $\Omega\subset\mathbb{R}^2$ concerning the existence of nonstationary collision-free periodic solutions. The problem in question is a first order Hamiltonian system of the form $$ \Gamma_k\dot{z}_k=J\nabla_{z_k}H(z_1,\ldots,z_N),\quad ... More
Approximating Probability Densities by Iterated Laplace ApproximationsMar 17 2011The Laplace approximation is an old, but frequently used method to approximate integrals for Bayesian calculations. In this paper we develop an extension of the Laplace approximation, by applying it iteratively to the residual, i.e., the difference between ... More
Feller Processes: The Next Generation in Modeling. Brownian Motion, Lévy Processes and BeyondSep 24 2010Dec 06 2010We present a simple construction method for Feller processes and a framework for the generation of sample paths of Feller processes. The construction is based on state space dependent mixing of L\'evy processes. Brownian Motion is one of the most frequently ... More
The Kellogg property and boundary regularity for p-harmonic functions with respect to the Mazurkiewicz boundary and other compactificationsMay 05 2017Oct 30 2018In this paper boundary regularity for p-harmonic functions is studied with respect to the Mazurkiewicz boundary and other compactifications. In particular, the Kellogg property (which says that the set of irregular boundary points has capacity zero) is ... More
Background Rejection of n$^+$ Surface Events in GERDA Phase IIMay 12 2016The GERDA experiment searches for neutrinoless double beta ($0\nu\beta\beta$) decay in $^{76}$Ge using an array of high purity germanium (HPGe) detectors immersed in liquid argon (LAr). Phase II of the experiment uses 30 new broad energy germanium (BEGe) ... More
A renormalization fixed point for Lorenz mapsAug 05 2009Mar 14 2010A Lorenz map is a Poincar\'e map for a three-dimensional Lorenz flow. We describe the theory of renormalization for Lorenz maps with a critical point and prove that a restriction of the renormalization operator acting on such maps has a hyperbolic fixed ... More
Squark and gaugino hadroproduction and decays in non-minimal flavour violating supersymmetryAug 28 2007Sep 24 2007We implement non-minimal flavour violation (NMFV) in the MSSM at low scale. In this framework, we propose benchmark points for the mSUGRA scenario including non-minimal flavour violation by evaluating a number of experimental low-energy, electroweak precision ... More
Effect of SUSY-QCD corrections to neutralino annihilation on the cold dark matter relic density in the Higgs funnelSep 14 2007We present a complete calculation of the QCD and SUSY-QCD corrections to neutralino pair annihilation into bottom quark-antiquark pairs through exchange of a pseudoscalar Higgs boson, which is the dominant process in the cosmological A-funnel region of ... More
Strict Upper Limits on the Carbon-to-Oxygen Ratios of Eight Hot Jupiters from Self-Consistent Atmospheric RetrievalApr 28 2015The elemental compositions of hot Jupiters are informative relics of planet formation that can help us answer long-standing questions regarding the origin and formation of giant planets. Here, I present the main conclusions from a comprehensive atmospheric ... More
Exponential transforms, resultants and momentsDec 04 2012We give an overview of some recent developments concerning harmonic and other moments of plane domains, their relationship to the Cauchy and exponential transforms, and to the meromorphic resultant and elimination function. The paper also connects to ... More
Dependence and dependence structures: estimation and visualization using distance multivarianceDec 18 2017Feb 07 2019Distance multivariance is a multivariate dependence measure, which can detect dependencies between an arbitrary number of random vectors each of which can have a distinct dimension. Here we discuss several new aspects and present a concise overview. We ... More
Markovian Maximal Coupling of Markov ProcessesOct 26 2017Markovian maximal couplings of Markov processes are characterized by an equality of total variation and a distance of Wasserstein type. If a Markovian maximal coupling is a Feller process, the generator can be calculated, e.g. for reflection coupled Brownian ... More
The string equation for non-univalent functionsMar 08 2018For conformal maps defined in the unit disk one can define a certain Poisson bracket that involves the harmonic moments of the image domain. When this bracket is applied to the conformal map itself together with its conformally reflected map the result ... More
Uniform Exponential Stabilisation of Serially Connected Inhomogeneous Euler-Bernoulli BeamsOct 24 2018We consider a chain of Euler-Bernoulli beams with spatial dependent mass density, modulus of elasticity and area moment which are interconnected in dissipative or conservative ways and prove uniform exponential energy decay of the coupled system for suitable ... More
The quasisuperminimizing constant for the minimum of two quasisuperminimizers in R^nFeb 26 2019It was shown in Bj\"orn--Bj\"orn--Korte ("Minima of quasisuperminimizers", Nonlinear Anal. 155 (2017), 264-284) that $u:=\min\{u_1,u_2\}$ is a $\overline{Q}$-quasisuperminimizer if $u_1$ and $u_2$ are $Q$-quasisuperminimizers and $\overline{Q}=2Q^2/(Q+1)$. ... More
A unified cluster expansion method applied to the configurational thermodynamics of cubic TiAlNDec 14 2010We study the thermodynamics of cubic Ti1-xAlxN using a unified cluster expansion approach for the alloy problem. The purely configurational part of the alloy Hamiltonian is expanded in terms of concentration and volume dependent effective cluster interactions. ... More
The Liouville theorem for $p$-harmonic functions and quasiminimizers with finite energySep 19 2018We show that, under certain geometric conditions, there are no nonconstant quasiminimizers with finite $p$th power energy in a (not necessarily complete) metric measure space equipped with a globally doubling measure supporting a global $p$-Poincar\'e ... More
The Cartan, Choquet and Kellogg properties for the fine topology on metric spacesOct 20 2014We prove the Cartan and Choquet properties for the fine topology on a complete metric space equipped with a doubling measure supporting a $p$-Poincar\'e inequality, $1 < p< \infty$. We apply these key tools to establish a fine version of the Kellogg property, ... More
Spatio-temporal Video Parsing for Abnormality DetectionFeb 22 2015Abnormality detection in video poses particular challenges due to the infinite size of the class of all irregular objects and behaviors. Thus no (or by far not enough) abnormal training samples are available and we need to find abnormalities in test data ... More
Stationary quantum coherence and transport in disordered networksMay 29 2013We examine the excitation transport across quantum networks that are continuously driven by a constant and incoherent light source. In particular we investigate the coherence properties of incoherently driven networks by employing recent tools from entanglement ... More
Critical points of Green's function and geometric function theoryDec 07 2009We study questions related to critical points of the Green's function of a bounded multiply connected domain in the complex plane. The motion of critical points, their limiting positions as the pole approaches the boundary and the differential geometry ... More
Convolutional RNN: an Enhanced Model for Extracting Features from Sequential DataFeb 18 2016Mar 01 2016Traditional convolutional layers extract features from patches of data by applying a non-linearity on an affine function of the input. We propose a model that enhances this feature extraction process for the case of sequential data, by feeding patches ... More
Momentum and position detection in nanoelectromechanical systems beyond Born and Markov approximationsDec 21 2010We propose and analyze different schemes to probe the quantum nature of nanoelectromechanical systems (NEMS) by a tunnel junction detector. Using the Keldysh technique, we are able to investigate the dynamics of the combined system for an arbitrary ratio ... More
Physical Measures for Infinitely Renormalizable Lorenz MapsDec 27 2014A physical measure on the attractor of a system describes the statistical behavior of typical orbits. An example occurs in unimodal dynamics. Namely, all infinitely renormalizable unimodal maps have a physical measure. For Lorenz dynamics, even in the ... More
On the Hyperbolicity of Lorenz RenormalizationMay 03 2012We consider infinitely renormalizable Lorenz maps with real critical exponent $\alpha>1$ and combinatorial type which is monotone and satisfies a long return condition. For these combinatorial types we prove the existence of periodic points of the renormalization ... More
How to Distinguish between Cloudy Mini-Neptunes and Water/Volatile-Dominated Super-EarthsJun 26 2013One of the most profound questions about the newly discovered class of low-density super-Earths is whether these exoplanets are predominately H2-dominated mini-Neptunes or volatile-rich worlds with gas envelopes dominated by H2O, CO2, CO, CH4, or N2. ... More
Fast Directional Computation for the High Frequency Helmholtz Kernel in Two DimensionsFeb 28 2008This paper introduces a directional multiscale algorithm for the two dimensional $N$-body problem of the Helmholtz kernel with applications to high frequency scattering. The algorithm follows the approach in [Engquist and Ying, SIAM Journal on Scientific ... More
Ranking and Selection: A New Sequential Bayesian Procedure for Use with Common Random NumbersOct 24 2014Jan 20 2017We want to select the best systems out of a given set of systems (or rank them) with respect to their expected performance. The systems allow random observations only and we assume that the joint observation of the systems has a multivariate normal distribution ... More
Optimization-based Motion Planning in Virtual Driving Scenarios with Application to Communicating Autonomous VehiclesJan 23 2018The paper addresses the problem of providing suitable reference trajectories in motion planning problems for autonomous vehicles. Among the various approaches to compute a reference trajectory, our aim is to find those trajectories which optimize a given ... More
On complex Gaussian random fields, Gaussian quadratic forms and sample distance multivarianceAug 22 2018Mar 19 2019The paper contains results in three areas: First we present a general estimate for tail probabilities of Gaussian quadratic forms with known expectation and variance. Thereafter we analyze the distribution of norms of complex Gaussian random fields (with ... More
Strong disorder in nodal semimetals: Schwinger-Dyson--Ward approachAug 29 2018Jan 12 2019The self-consistent Born approximation quantitatively fails to capture disorder effects in semimetals. We present an alternative, simple-to-use non-perturbative approach to calculate the disorder induced self-energy. It requires a sufficient broadening ... More
The annular decay property and capacity estimates for thin annuliDec 21 2015We obtain upper and lower bounds for the nonlinear variational capacity of thin annuli in weighted $\mathbf{R}^n$ and in metric spaces, primarily under the assumptions of an annular decay property and a Poincar\'e inequality. In particular, if the measure ... More
Quasiopen and p-path open sets, and characterizations of quasicontinuitySep 08 2015In this paper we give various characterizations of quasiopen sets and quasicontinuous functions on metric spaces. For complete metric spaces equipped with a doubling measure supporting a p-Poincar\'e inequality we show that quasiopen and p-path open sets ... More
The Mazurkiewicz distance and sets that are finitely connected at the boundaryNov 20 2013We study local connectedness, local accessibility and finite connectedness at the boundary, in relation to the compactness of the Mazurkiewicz completion of a bounded domain in a metric space. For countably connected planar domains we obtain a complete ... More
The Dirichlet problem for p-harmonic functions with respect to arbitrary compactificationsApr 29 2016We study the Dirichlet problem for p-harmonic functions on metric spaces with respect to arbitrary compactifications. A particular focus is on the Perron method, and as a new approach to the invariance problem we introduce Sobolev-Perron solutions. We ... More
The Petrovskiĭ criterion and barriers for degenerate and singular p-parabolic equationsSep 08 2015Mar 01 2016In this paper we obtain sharp Petrovskii criteria for the p-parabolic equation, both in the degenerate case p>2 and the singular case 1<p<2. We also give an example of an irregular boundary point at which there is a barrier, thus showing that regularity ... More
Minima of quasisuperminimizersMay 19 2015Let u_i be a Q_i-quasisuperminimizer, i=1,2, and u=min{u_1,u_2}, where 1 <= Q_1 <= Q_2. Then u is a quasisuperminimizer, and we improve upon the known upper bound (due to Kinnunen and Martio) for the optimal quasisuperminimizing constant Q of u. We give ... More
The tusk condition and Petrovski criterion for the normalized $p\mspace{1mu}$-parabolic equationDec 19 2017We study boundary regularity for the normalized $p\mspace{1mu}$-parabolic equation in arbitrary bounded domains. Effros and Kazdan (Indiana Univ. Math. J. 20 (1970), 683-693) showed that the so-called tusk condition guarantees regularity for the heat ... More
An axiomatic approach to gradients with applications to Dirichlet and obstacle problems beyond function spacesJan 27 2015We develop a framework for studying variational problems in Banach spaces with respect to gradient relations, which encompasses many of the notions of generalized gradients that appear in the literature. We stress the fact that our approach is not dependent ... More
The weak Cartan property for the p-fine topology on metric spacesOct 30 2013We study the p-fine topology on complete metric spaces equipped with a doubling measure supporting a p-Poincare inequality, 1 < p< oo. We establish a weak Cartan property, which yields characterizations of the p-thinness and the p-fine continuity, and ... More
Devices with electrically tunable topological insulating phasesJan 09 2013Feb 28 2013Solid-state topological insulating phases, characterized by spin-momentum locked edge modes, provide a powerful route for spin and charge manipulation in electronic devices. We propose to control charge and spin transport in the helical edge modes by ... More
Parity measurement in topological Josephson junctionsMay 31 2013We study the properties of a topological Josephson junction made of both edges of a 2D topological insulator. We show that, due to fermion parity pumping across the bulk, the global parity of the junction has a clear signature in the periodicity and critical ... More
Stability and Complexity of Minimising Probabilistic AutomataApr 26 2014May 01 2014We consider the state-minimisation problem for weighted and probabilistic automata. We provide a numerically stable polynomial-time minimisation algorithm for weighted automata, with guaranteed bounds on the numerical error when run with floating-point ... More
Nonlinear left and right eigenvectors for max-preserving mapsSep 20 2016It is shown that max-preserving maps (or join-morphisms) on the positive orthant in Euclidean $n$-space endowed with the component-wise partial order give rise to a semiring. This semiring admits a closure operation for maps that generate stable dynamical ... More
Flux-Dependent Level Attraction in Double-Dot Aharonov-Bohm InterferometersOct 24 2001Jun 04 2002We study electron transport through a closed Aharonov-Bohm interferometer containing two single-level quantum dots. The quantum-dot levels are coupled to each other indirectly via the leads. We find that this coupling yields signatures of an effective ... More
Neutralino annihilation to quarks with SUSY-QCD correctionsNov 10 2008The calculation of the cosmological relic density of the dark matter candidate within supersymmetric models is an interesting possibility to obtain additional constraints on the supersymmetric parameter space with respect to collider, electroweak precision, ... More
Topological invariants for the Haldane phase of interacting SSH chains -- a functional RG approachMay 02 2018Oct 01 2018We present a functional renormalization group approach to interacting topological Green function invariants with a focus on the nature of transitions. The method is applied to chiral symmetric fermion chains in the Mott limit that can be driven into a ... More
Global continua of periodic solutions of singular first-order Hamiltonian systems of N-vortex typeApr 06 2016The paper deals with singular first order Hamiltonian systems of the form \[ \Gamma_k\dot{z}_k(t)=J\nabla_{z_k} H\big(z(t)\big),\quad z_k(t) \in \Omega \subset \mathbb{R}^2,\ k=1,\dots,N, \] where $J\in\mathbb{R}^{2\times2}$ defines the standard symplectic ... More
On a generalization of the preconditioned Crank-Nicolson Metropolis algorithmApr 14 2015Oct 12 2016Metropolis algorithms for approximate sampling of probability measures on infinite dimensional Hilbert spaces are considered and a generalization of the preconditioned Crank-Nicolson (pCN) proposal is introduced. The new proposal is able to incorporate ... More
On complex Gaussian random fields, Gaussian quadratic forms and sample distance multivarianceAug 22 2018The paper contains results in three areas: First we present a general estimate for tail probabilities of Gaussian quadratic forms with known expectation and variance. Thereafter we analyze the distribution of norms of complex Gaussian random fields (with ... More
$\mathcal{N}=1$ Supersymmetric $SU(3)$ Gauge Theory - Towards simulations of Super-QCDNov 05 2018$\mathcal{N}=1$ supersymmetric QCD (SQCD) is a possible building block of theories beyond the standard model. It describes the interaction between gluons and quarks with their superpartners, gluinos and squarks. Since supersymmetry is explicitly broken ... More
Energy and system size dependence of subnucleonic fluctuationsJul 11 2018The energy evolution of the fluctuating proton structure is studied by solving the JIMWLK renormalization group equation. The initial condition at moderate $x$ is obtained by fitting the charm reduced cross section data from HERA, requiring that the proton ... More
On the Finite Dimensionality of Spaces of Absolutely Convergent Fourier TransformsMay 12 2013We extend the result of K. Karlander [Math. Scand. 80 (1997)] regarding finite dimensionality of spaces of absolutely convergent Fourier transforms.
Microphysics of KCl and ZnS Clouds on GJ 1214bJul 13 2018Clouds in the atmospheres of exoplanets confound characterization efforts by reducing, eliminating, and distorting spectral signatures of molecular abundances. As such, interpretations of exoplanet spectra strongly depend on the choice of cloud model, ... More
Risk aggregation and stochastic claims reserving in disability insuranceJan 15 2014Aug 26 2014We consider a large, homogeneous portfolio of life or disability annuity policies. The policies are assumed to be independent conditional on an external stochastic process representing the economic-demographic environment. Using a conditional law of large ... More
AC-Conductance through an Interacting Quantum DotOct 15 2009We investigate the linear ac-conductance for tunneling through an arbitrary interacting quantum dot in the presence of a finite dc-bias. In analogy to the well-known Meir-Wingreen formula for the dc case, we are able to derive a general formula for the ... More
Hybrid model calculations of direct photons in high-energy nuclear collisionsMay 28 2009Mar 04 2010Direct photon emission in heavy-ion collisions is calculated within a relativistic micro+macro hybrid model and compared to the microscopic transport model UrQMD. In the hybrid approach, the high-density part of the evolution is replaced by an ideal 3-dimensional ... More
Deep Impact: Unintended consequences of journal rankJan 16 2013May 10 2013Most researchers acknowledge an intrinsic hierarchy in the scholarly journals ('journal rank') that they submit their work to, and adjust not only their submission but also their reading strategies accordingly. On the other hand, much has been written ... More
Ranking and Selection: A New Sequential Bayesian Procedure for Use with Common Random NumbersOct 24 2014We want to select the best systems out of a given set of systems (or rank them) with respect to their expected performance. The systems allow random observations only and we assume that the joint observation of the systems has a multivariate normal distribution ... More
Measuring the Kondo Cloud by Current Cross Correlations in Helical LiquidsOct 24 2013Feb 02 2014The Kondo cloud, represented by the correlations between the magnetic moment and the spin density in the leads of a Kondo setup, is until now eluding its observation. We exploit the unique coupling of spin and direction of motion of the recently discovered ... More
Tuning of the strange quark mass with optimal reweightingJan 26 2015Quark mass reweighting can be used to tune the mass of dynamical quarks. The basic idea is to use gauge field ensembles generated at some bare mass parameters to evaluate observables at different bare sea quark masses. This involves the computation of ... More
Hierarchy-based Image Embeddings for Semantic Image RetrievalSep 26 2018Nov 21 2018Deep neural networks trained for classification have been found to learn powerful image representations, which are also often used for other tasks such as comparing images w.r.t. their visual similarity. However, visual similarity does not imply semantic ... More
Nonuniform sampling and multiscale computationSep 10 2013Aug 24 2014In homogenization theory and multiscale modeling, typical functions satisfy the scaling law $f^{\epsilon}(x) = f(x,x/\epsilon)$, where $f$ is periodic in the second variable and $\epsilon$ is the smallest relevant wavelength, $0<\epsilon\ll1$. Our main ... More
Elastic flow interacting with a lateral diffusion process: The one-dimensional graph caseJul 26 2017A finite element approach to the elastic flow of a curve coupled with a diffusion equation on the curve is analysed. Considering the graph case, the problem is weakly formulated and approximated with continuous linear finite elements, which is enabled ... More
Partial Balayage on Riemannian ManifoldsMay 10 2016A general theory of partial balayage on Riemannian manifolds is developed, with emphasis on compact manifolds. Partial balayage is an operation of sweeping measures, or charge distributions, to a prescribed density, and it is closely related to (construction ... More
Revealing proton shape fluctuations with incoherent diffraction at high energyJul 06 2016Aug 30 2016The differential cross section of exclusive diffractive vector meson production in electron proton collisions carries important information on the geometric structure of the proton. More specifically, the coherent cross section as a function of the transferred ... More
Stability and Stabilization of Infinite-dimensional Linear Port-Hamiltonian SystemsDec 16 2013Stability and stabilization of linear port-Hamiltonian systems on infinite-dimensional spaces are investigated. This class is general enough to include models of beams and waves as well as transport and Schr\"odinger equations with boundary control and ... More
Impact parameter dependent JIMWLK evolution meets HERA dataNov 09 2018We calculate the small-$x$ evolution of protons with finite size by solving numerically the JIMWLK evolution equation. The initial condition is constrained by the HERA measurements of charm reduced cross section and of exclusive vector meson production. ... More
Phase-dependent heat and charge transport through superconductor-quantum dot hybridsSep 25 2018Jan 25 2019We analyze heat and charge transport through a single-level quantum dot coupled to two BCS superconductors at different temperatures to first order in the tunnel coupling. In order to describe the system theoretically, we extend a real-time diagrammatic ... More
On a Metropolis-Hastings importance sampling estimatorMay 18 2018May 24 2018A classical approach for approximating expectations of functions w.r.t. partially known distributions is to compute the average of function values along a trajectory of a Metropolis-Hastings (MH) Markov chain. A key part in the MH algorithm is a suitable ... More
Regularity of $p(\cdot)$-superharmonic functions, the Kellogg property and semiregular boundary pointsFeb 01 2013We study various boundary and inner regularity questions for $p(\cdot)$-(super)harmonic functions in Euclidean domains. In particular, we prove the Kellogg property and introduce a classification of boundary points for $p(\cdot)$-harmonic functions into ... More
Sobolev spaces, fine gradients and quasicontinuity on quasiopen setsApr 30 2015We study different definitions of Sobolev spaces on quasiopen sets in a complete metric space equipped with a doubling measure supporting a p-Poincar\'e inequality with 1<p<\infty, and connect them to the Sobolev theory in R^n. In particular, we show ... More