Results for "Björn Alling"

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Lattice relaxations in disordered Fe-based materials in the paramagnetic state from first principlesMay 25 2018In this work we propose a method for the structural relaxation of magnetic materials in the paramagnetic regime, in an adiabatic fast-magnetism approximation within the disordered local moment (DLM) picture in the framework of density functional theory ... More
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
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
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
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
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
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
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
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
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
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
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
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
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
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
The Lorenz Renormalization ConjectureMay 03 2018The renormalization paradigm for low-dimensional dynamical systems is that of hyperbolic horseshoe dynamics. Does this paradigm survive a transition to more physically relevant systems in higher dimensions? This article addresses this question in the ... 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
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.
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
Vortex motion and geometric function theory: the role of connectionsNov 23 2018We formulate the equations for point vortex dynamics on a closed two dimensional Riemann manifold in the language of affine and other kinds of connections. The speed of a vortex is then expressed in terms of the difference between an affine connection ... 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
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
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
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
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
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
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 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
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
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
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
Summing up Ultra-High-Energy Cosmic Rays from Radio GalaxiesDec 22 2018Radio galaxies are intensively discussed as the sources of cosmic rays observed above about 3 EeV, called ultra-high-energy cosmic rays (UHECRs). Here, the key issues from a recent investigation are summed up, where the individual characteristics of radio ... 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
Stabilization Bounds for Linear Finite Dynamical SystemsMar 31 2017Mar 29 2019A 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
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
High Energy Cosmic Rays from Fanaroff-Riley Radio GalaxiesFeb 01 2019May 09 2019The extended jet structures of radio galaxies (RGs) represent an ideal acceleration site for High Energy Cosmic Rays (HECRs) and a recent model showed that the HECR data can be explained by these sources, if the arrival directions of HECRs at energies ... 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
Well-posedness and Stability for Interconnection Structures of Port-Hamiltonian TypeOct 01 2018Jun 13 2019We 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
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
On the Locally Lipschitz Robustness of Bayesian Inverse ProblemsJun 17 2019In this note we consider the robustness of posterior measures occuring in Bayesian inference w.r.t. perturbations of the prior measure and the log-likelihood function. This extends the well-posedness analysis of Bayesian inverse problems. In particular, ... 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
Existence and almost uniqueness for $p$-harmonic Green functions on bounded domains in metric spacesJun 24 2019We study ($p$-harmonic) singular functions, defined by means of upper gradients, in bounded domains in metric measure spaces. It is shown that singular functions exist if and only if the complement of the domain has positive capacity, and that they satisfy ... 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
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
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
The critical point of the transition to turbulence in pipe flowSep 19 2017Reynolds proposed that after sufficiently long times, the flow in a pipe should settle to a steady condition: below a critical Reynolds number, flows should (regardless of initial conditions) always return to laminar, while above, eddying motion should ... More
Likelihood Ratio Tests for a Dose-Response Effect using Multiple Nonlinear Regression ModelsOct 21 2015We consider the problem of testing for a dose-related effect based on a candidate set of (typically nonlinear) dose-response models using likelihood-ratio tests. For the considered models this reduces to assessing whether the slope parameter in these ... 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
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
Counting attractors in synchronously updated random Boolean networksDec 16 2004Despite their apparent simplicity, random Boolean networks display a rich variety of dynamical behaviors. Much work has been focused on the properties and abundance of attractors. We here derive an expression for the number of attractors in the special ... 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
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
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
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
Syntactic cut-elimination and backward proof-search for tense logic via linear nested sequents (Extended version)Jul 02 2019We give a linear nested sequent calculus for the basic normal tense logic Kt. We show that the calculus enables backwards proof-search, counter-model construction and syntactic cut-elimination. Linear nested sequents thus provide the minimal amount of ... 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
Sharp capacity estimates for annuli in weighted R^n and in metric spacesDec 05 2013We obtain estimates for the nonlinear variational capacity of annuli in weighted R^n and in metric spaces. We introduce four different (pointwise) exponent sets, show that they all play fundamental roles for capacity estimates, and also demonstrate that ... 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
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 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
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
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
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
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
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
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
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
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
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
Seismic Inversion and the Data Normalization for Optimal TransportOct 19 2018Full waveform inversion (FWI) has recently become a favorite technique for the inverse problem of finding properties in the earth from measurements of vibrations of seismic waves on the surface. Mathematically, FWI is PDE constrained optimization where ... 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
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 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.
Improving Study Skills using Program Integrating Reflection SeminarsAug 01 2016If students have a broad spectrum of study skills, learning will likely be positively affected, since they can adapt the way they learn in different situations. Such study skills can be learned in for example learning-to-learn courses. Several studies ... More
Estimating Maximum Error Impact in Dynamic Data-driven Applications for Resource-aware Adaption of Software-based Fault-ToleranceAug 22 2016The rise of transient faults in modern hardware requires system designers to consider errors occurring at runtime. Both hardware- and software-based error handling must be deployed to meet application reliability requirements. The level of required reliability ... More
Quantum-fluctuation effects on the thermopower of a single-electron transistorFeb 27 2006Sep 18 2006We study thermal conductance and thermopower of a metallic single-electron transistor beyond the limit of weak tunnel coupling. Employing both a systematic second-order perturbation expansion and a non-perturbative approximation scheme, we find, in addition ... More