Results for "Andreas Dedner"

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Efficient Multigrid Preconditioners for Atmospheric Flow Simulations at High Aspect RatioAug 13 2014Feb 10 2015Many problems in fluid modelling require the efficient solution of highly anisotropic elliptic partial differential equations (PDEs) in "flat" domains. For example, in numerical weather- and climate-prediction an elliptic PDE for the pressure correction ... More
Python Framework for HP Adaptive Discontinuous Galerkin Method for Two Phase Flow in Porous MediaMay 01 2018In this paper we present a framework for solving two phase flow problems in porous media. The discretization is based on a Discontinuous Galerkin method and includes local grid adaptivity and local choice of polynomial degree. The method is implemented ... More
Discontinuous Galerkin methods for hyperbolic and advection-dominated problems on surfacesMay 25 2015We extend the discontinuous Galerkin (DG) framework to the analysis of first-order hyperbolic and advection-dominated problems posed on implicitly defined surfaces. The focus will be on the hyperbolic part, which is discretised using a "discrete surface" ... More
Adaptive discontinuous Galerkin methods on surfacesFeb 10 2014We present a dual weighted residual-based a posteriori error estimate for a discontinuous Galerkin (DG) approximation of a linear second-order elliptic problem on compact smooth connected and oriented surfaces in $\mathbb{R}^{3}$ which are implicitly ... More
Discontinuous Galerkin methods for nonvariational problemsApr 08 2013We extend the finite element method introduced by Lakkis and Pryer [2011] to approximate the solution of second order elliptic problems in nonvariational form to incorporate the discontinuous Galerkin (DG) framework. This is done by viewing the NVFEM ... More
A posteriori analysis of fully discrete method of lines DG schemes for systems of conservation lawsOct 19 2015We present reliable a posteriori estimators for some fully discrete schemes applied to nonlinear systems of hyperbolic conservation laws in one space dimension with strictly convex entropy. The schemes are based on a method of lines approach combining ... More
The Dune Python ModuleJul 13 2018In this paper we present the new Dune-Python module which provides Python bindings for the Dune core, which is a C++ environment for solving partial differential equations. The aim of this new module is to firstly provide the general infrastructure for ... More
Analysis of the discontinuous Galerkin method for elliptic problems on surfacesMar 25 2012Jan 10 2013We extend the discontinuous Galerkin (DG) framework to a linear second-order elliptic problem on a compact smooth connected and oriented surface. An interior penalty (IP) method is introduced on a discrete surface and we derive a-priori error estimates ... More
The DUNE-ALUGrid ModuleJul 25 2014Aug 15 2015In this paper we present the new DUNE-ALUGrid module. This module contains a major overhaul of the sources from the ALUgrid library and the binding to the DUNE software framework. The main changes include user defined load balancing, parallel grid construction, ... More
Phase field methods for binary recoveryOct 17 2013We consider the inverse problem of recovering a binary function from blurred and noisy data. Such problems arise in many applications, for example image processing and optimal control of PDEs. Our formulation is based on the Mumford-Shah model, but with ... More
Residual estimates for post-processors in elliptic problemsJun 11 2019In this work we examine a posteriori error control for post-processed approximations to elliptic boundary value problems. We introduce a class of post-processing operator that `tweaks' a wide variety of existing post-processing techniques to enable efficient ... More
High order discontinuous Galerkin methods on surfacesFeb 14 2014Apr 09 2014We derive and analyze high order discontinuous Galerkin methods for second-order elliptic problems on implicitely defined surfaces in $\mathbb{R}^{3}$. This is done by carefully adapting the unified discontinuous Galerkin framework of Arnold et al. [2002] ... More
Convection in a Single Column -- Modelling, Algorithm and AnalysisAug 18 2016The group focused on a model problem of idealised moist air convection in a single column of atmosphere. Height, temperature and moisture variables were chosen to simplify the mathematical representation (along the lines of the Boussinesq approximation ... More
Coupling Atomistic, Elasticity and Boundary Element ModelsSep 15 2017Sep 23 2017We formulate a new atomistic/continuum (a/c) coupling scheme that employs the boundary element method (BEM) to obtain an improved far-field boundary condition. We establish sharp error bounds in a 2D model problem for a point defect embedded in a homogeneous ... More
Analysis of patch-test consistent atomistic-to-continuum coupling with higher-order finite elementsJul 20 2016We formulate a patch test consistent atomistic-to-continuum coupling (a/c) scheme that employs a second-order (potentially higher-order) finite element method in the material bulk. We prove a sharp error estimate in the energy-norm, which demonstrates ... More
Optimal control of elliptic PDEs at pointsNov 18 2014We consider an elliptic optimal control problem where the objective functional contains evaluations of the state at a finite number of points. In particular, we use a fidelity term that encourages the state to take certain values at these points, which ... More
Optimal control of elliptic PDEs on surfaces of codimension 1Nov 18 2014We consider an elliptic optimal control problem where the objective functional contains an integral along a surface of codimension 1, also known as a hypersurface. In particular, we use a fidelity term that encourages the state to take certain values ... More
The antiferromagnetic spin-1/2 Heisenberg model on the square lattice in a magnetic fieldDec 17 2008Mar 16 2009We study the field dependence of the antiferromagnetic spin-1/2 Heisenberg model on the square lattice by means of exact diagonalizations. In a first part, we calculate the spin-wave velocity, the spin-stiffness, and the magnetic susceptibility and thus ... More
Solving DC programs with polyhedral component utilizing a multiple objective linear programming solverOct 18 2016A class of non-convex optimization problems with DC objective function and linear constraints is studied, where DC stands for being representable as the difference $f=g-h$ of two convex functions $g$ and $h$. In particular, we deal with the special case ... More
Formality of $\mathbb{P}$-objectsSep 19 2017We show that a $\mathbb{P}$-object and simple configurations of $\mathbb{P}$-objects have a formal derived endomorphism algebra. Hence the triangulated category (classically) generated by such objects is independent of the ambient triangulated category. ... More
Particle-particle ladder based basis-set corrections applied to atoms and molecules using coupled-cluster theoryMar 13 2019May 21 2019We investigate the basis-set convergence of coupled cluster electronic correlation energies using a recently proposed finite basis-set correction technique. The correction is applied to atomic and molecular systems and is based on a diagrammatically decomposed ... More
(a,b)-Koszul algebrasJul 20 2010Let $a$ and $b$ be two integers such that $2\le a<b$. In this article we define the notion of $(a,b)$-Koszul algebra as a generalization of $N$-Koszul algebras. We also exhibit examples and we provide a minimal graded projective resolution of the algebra ... More
Status of sub-GeV Hidden Particle SearchesAug 26 2010Hidden sector particles with sub-GeV masses like hidden U(1) gauge bosons, the NMSSM CP-odd Higgs, and other axion-like particles are experimentally little constrained as they interact only very weakly with the visible sector. For masses below the muon ... More
The electroweak chiral Lagrangian reanalyzedJul 09 1999Oct 26 2000In this paper we reanalyze the electroweak chiral Lagrangian with particular focus on two issues related to gauge invariance. Our analysis is based on a manifestly gauge-invariant approach that we introduced recently. It deals with gauge-invariant Green's ... More
A universal ionization threshold for strongly driven Rydberg statesApr 21 2004We observe a universal ionization threshold for microwave driven one-electron Rydberg states of H, Li, Na, and Rb, in an {\em ab initio} numerical treatment without adjustable parameters. This sheds new light on old experimental data, and widens the scene ... More
Residual Symmetries in the Spectrum of Periodically Driven Alkali Rydberg StatesNov 25 1999We identify a fundamental structure in the spectrum of microwave driven alkali Rydberg states, which highlights the remnants of the Coulomb symmetry in the presence of a non-hydrogenic core. Core-induced corrections with respect to the hydrogen spectrum ... More
Particle-particle ladder based basis-set corrections applied to atoms and molecules using coupled-cluster theoryMar 13 2019We investigate the basis-set convergence of coupled cluster electronic correlation energies using a recently proposed finite basis-set correction technique. The correction is applied to atomic and molecular systems and is based on a diagrammatically decomposed ... More
A Multilevel Monte Carlo Algorithm for Parabolic Advection-Diffusion Problems with Discontinuous CoefficientsFeb 06 2019The Richards' equation is a model for flow of water in unsaturated soils. The coefficients of this (nonlinear) partial differential equation describe the permeability of the medium. Insufficient or uncertain measurements are commonly modeled by random ... More
Lipschitz functions with prescribed blowups at many pointsDec 15 2016In this paper we prove generalizations of Lusin-type theorems for gradients due to Giovanni Alberti, where we replace the Lebesgue measure with any Radon measure $\mu$. We apply this to go beyond the known result on the existence of Lipschitz functions ... More
Particle-particle ladder based basis-set corrections applied to atoms and molecules using coupled-cluster theoryMar 13 2019Mar 14 2019We investigate the basis-set convergence of coupled cluster electronic correlation energies using a recently proposed finite basis-set correction technique. The correction is applied to atomic and molecular systems and is based on a diagrammatically decomposed ... More
Inverse Scattering for the Laplace operator with boundary conditions on Lipschitz surfacesJan 26 2019Feb 17 2019We provide a general scheme, in the combined frameworks of Mathematical Scattering Theory and Factorization Method, for inverse scattering for the couple of self-adjoint operators $(\widetilde\Delta,\Delta)$, where $\Delta$ is the free Laplacian in $L^{2}({\mathbb ... More
Formality of $\mathbb{P}$-objectsSep 19 2017May 06 2019We show that a $\mathbb{P}$-object and simple configurations of $\mathbb{P}$-objects have a formal derived endomorphism algebra. Hence the triangulated category (classically) generated by such objects is independent of the ambient triangulated category. ... More
Tanaka structures modeled on extended Poincaré algebrasJan 03 2012Oct 04 2012Let (V,(.,.)) be a pseudo-Euclidean vector space and S an irreducible Cl(V)-module. An extended translation algebra is a graded Lie algebra m = m_{-2}+m_{-1} = V+S with bracket given by ([s,t],v) = b(v.s,t) for some nondegenerate so(V)-invariant reflexive ... More
Equivariant characteristic forms in the Cartan model and Borel equivariant cohomologyAug 31 2015Nov 10 2015We show the compatibility of the differential geometric and the topological construction of equivariant characteristic classes for compact Lie groups. Our analysis motivates a differential geometric construction for equivariant characteristic classes ... More
Band-edge BCS-BEC crossover in a two-band superconductor: physical properties and detection parametersJul 11 2014Superconductivity in iron-based, magnesium diborides, and other novel superconducting materials has a strong multi-band and multi-gap character. Recent experiments support the possibillity for a BCS-BEC crossover induced by strong-coupling and proximity ... More
Ethemba Trusted Host EnvironmentMainly Based on AttestationJan 28 2009Ethemba provides a framework and demonstrator for TPM applications.
Thermodynamic properties and thermal correlation lengths of a Hubbard model with bond-charge interactionFeb 27 2004We investigate the thermodynamics of a one-dimensional Hubbard model with bond-charge interaction X using the transfer matrix renormalization group method (TMRG). Numerical results for various quantities like spin and charge susceptibilities, particle ... More
Imbalanced thee-component Fermi gas with attractive interactions: Multiple FFLO-pairing, Bose-Fermi and Fermi-Fermi mixtures versus collapse and phase separationJun 04 2009We present a detailed study of the population imbalanced three-component Hubbard chain with attractive interactions. Such a system can be realized experimentally with three different hyperfine states of ultra cold $^6$Li atoms in an optical lattice. We ... More
Domestic Corpuscular InflatonJun 28 2018The aim of this paper is to provide a more precise description of the paradigm of corpuscular slow-roll inflation, which was previously introduced by Casadio et al. in [1]. Specifically, we start by expanding the Starobinsky theory on a curved background ... More
Inverse wave scattering in the time domain: a factorization method approachMar 14 2019Let $\Delta_{\Lambda}\le \lambda_{\Lambda}$ be a semi-bounded self-adjoint realization of the Laplace operator with boundary conditions assigned on the Lipschitz boundary of a bounded obstacle $\Omega$. Let $u^{\Lambda}_{f}$ and $u^{0}_{f}$ be the solutions ... More
Classification of maximal transitive prolongations of super-Poincaré algebrasDec 08 2012Jul 22 2014Let $V$ be a complex vector space with a non-degenerate symmetric bilinear form and $\mathbb S$ an irreducible module over the Clifford algebra $Cl(V)$ determined by this form. A supertranslation algebra is a $\mathbb Z$-graded Lie superalgebra $\mathfrak ... More
Super-Poincare' algebras, space-times and supergravities (II)Aug 31 2011The presentation of supergravity theories of our previous paper "Super-Poincare' algebras, space-times and supergravities (I)" is re-formulated in the language of Berezin-Leites-Kostant theory of supermanifolds. It is also shown that the equations of ... More
Numerical analysis for time-dependent advection-diffusion problems with random discontinuous coefficientsFeb 06 2019Subsurface flows are commonly modeled by advection-diffusion equations. Insufficient measurements or uncertain material procurement may be accounted for by random coefficients. To represent, for example, transitions in heterogeneous media, the parameters ... More
PT-symmetrically deformed shock wavesJan 27 2012We investigate for a large class of nonlinear wave equations, which allow for shock wave formations, how these solutions behave when they are PT-symmetrically deformed. For real solutions we find that they are transformed into peaked solutions with a ... More
Numerical analysis of detection-mechanism models of SNSPDAug 27 2013Nov 12 2013The microscopic mechanism of photon detection in superconducting nanowire single-photon detectors is still under debate. We present a simple, but powerful theoretical model that allows us to identify essential differences between competing detection mechanisms. ... More
A Multilevel Monte Carlo Algorithm for Parabolic Advection-Diffusion Problems with Discontinuous CoefficientsFeb 06 2019Apr 18 2019The Richards' equation is a model for flow of water in unsaturated soils. The coefficients of this (nonlinear) partial differential equation describe the permeability of the medium. Insufficient or uncertain measurements are commonly modeled by random ... More
Gauge-invariant Green's functions for the bosonic sector of the standard modelDec 18 1998Jun 21 2000There are many applications in gauge theories where the usually employed framework involving gauge-dependent Green's functions leads to considerable problems. In order to overcome the difficulties invariably tied to gauge dependence, we present a manifestly ... More
Equivariant Differential CohomologyOct 21 2015Nov 10 2015The construction of characteristic classes via the curvature form of a connection is one motivation for the refinement of integral cohomology by de Rham cocycles -- known as differential cohomology. We will discuss the analog in the case of a group action ... More
Lipschitz functions with prescribed blowups at many pointsDec 15 2016May 04 2019In this paper we prove generalizations of Lusin-type theorems for gradients due to Giovanni Alberti, where we replace the Lebesgue measure with any Radon measure $\mu$. We apply this to go beyond the known result on the existence of Lipschitz functions ... More
Challenges for New Physics in the Flavour SectorSep 02 2014Sep 11 2014In these proceedings I present a personal perspective of the challenges for new physics (NP) searches in the flavour sector. Since the CKM mechanism of flavour violation has been established to a very high precision, we know that physics beyond the Standard ... More
The myth of the Digital Earth between fragmentation and wholenessDec 03 2014Daring predictions of the proximate future can establish shared discursive frameworks, mobilize capital, and steer complex processes. Among the prophetic visions that encouraged and accompanied the development of new communication technologies was the ... More
Moments and Absolute Moments of the Normal DistributionSep 19 2012Jul 15 2014We present formulas for the (raw and central) moments and absolute moments of the normal distribution. We note that these results are not new, yet many textbooks miss out on at least some of them. Hence, we believe that it is worthwhile to collect these ... More
Charged-Lepton Flavour PhysicsJan 24 2012Feb 09 2012This writeup of a talk at the 2011 Lepton-Photon symposium in Mumbai, India, summarises recent results in the charged-lepton flavour sector. I review searches for charged-lepton flavour violation, lepton electric dipole moments and flavour-conserving ... More
Discovering Higgs boson pair production through rare final states at a 100 TeV colliderApr 17 2015Nov 03 2015We consider Higgs boson pair production at a future proton collider with centre-of-mass energy of 100 TeV, focusing on rare final states that include a bottom-anti-bottom quark pair and multiple isolated leptons: $hh \rightarrow (b\bar{b}) + n \ell + ... More
Species, chameleonic strings and the concept of particleJun 21 2012We recently proposed a chameleonic solution to the cosmological constant problem - Phys. Rev. D82 (2010) 044006. We further elaborate on our proposal discussing also some new results. The basic ingredients of the model are A) a chameleonic string dilaton ... More
Prescribing metrics on the boundary of AdS 3-manifoldsApr 18 2016We prove that given two metrics $g_{+}$ and $g_{-}$ with curvature $\kappa <-1$ on a closed, oriented surface $S$ of genus $\tau\geq 2$, there exists an $AdS$ manifold $N$ with smooth, space-like, strictly convex boundary such that the induced metrics ... More
Constant mean curvature foliation of domains of dependence in $AdS_{3}$Oct 27 2016We prove that, given an acausal curve $\Gamma$ in the boundary at infinity of $AdS_{3}$ which is the graph of a quasi-symmetric homeomorphism $\phi$, there exists a unique foliation of its domain of dependence $D(\Gamma)$ by constant mean curvature surfaces ... More
Statistical Physics of Traffic FlowJul 26 2000The modelling of traffic flow using methods and models from physics has a long history. In recent years especially cellular automata models have allowed for large-scale simulations of large traffic networks faster than real time. On the other hand, these ... More
Role of feedback and broadcasting in the naming gameSep 24 2010Apr 12 2011The naming game (NG) describes the agreement dynamics of a population of agents that interact locally in a pairwise fashion, and in recent years statistical physics tools and techniques have greatly contributed to shed light on its rich phenomenology. ... More
Quantum resonances and time decay for a double-barrier modelNov 17 2014Here we consider the time evolution of a one-dimensional quantum system with a double barrier given by a couple of two repulsive Dirac's deltas. In such a "pedagogical" model we give, by means of the theory of quantum resonances, the explicit expression ... More
Conformal Metrics with Constant Q-CurvatureDec 13 2007We consider the problem of varying conformally the metric of a four dimensional manifold in order to obtain constant $Q$-curvature. The problem is variational, and solutions are in general found as critical points of saddle type. We show how the problem ... More
Thermodynamics and concentrationMay 08 2012We show that the thermal subadditivity of entropy provides a common basis to derive a strong form of the bounded difference inequality and related results as well as more recent inequalities applicable to convex Lipschitz functions, random symmetric matrices, ... More
A Note on the PAC Bayesian TheoremNov 30 2004We prove general exponential moment inequalities for averages of [0,1]-valued iid random variables and use them to tighten the PAC Bayesian Theorem. The logarithmic dependence on the sample count in the enumerator of the PAC Bayesian bound is halved.
Results of beyond the Standard Model Higgs searches from the LEP experimentsOct 31 2006Since no Standard Model Higgs boson was discovered at LEP the searches were extended to beyond the Standard Model Higgs scenarios. A selection of final results from searches carried out by the four LEP experiments ALEPH, DELPHI, L3 and OPAL are presented ... More
Background field dependence from the Slavnov-Taylor identity in (non-perturbative) Yang-Mills theoryDec 08 2011We show that in Yang-Mills theory the Slavnov-Taylor (ST) identity, extended in the presence of a background gauge connection, allows to fix in a unique way the dependence of the vertex functional on the background, once the 1-PI amplitudes at zero background ... More
On a class of embeddings of massive Yang-Mills theoryOct 31 2003Jan 12 2004A power-counting renormalizable model into which massive Yang-Mills theory is embedded is analyzed. The model is invariant under a nilpotent BRST differential s. The physical observables of the embedding theory, defined by the cohomology classes of s ... More
Slavnov-Taylor Parameterization for the Quantum Restoration of BRST Symmetries in Anomaly-Free Gauge TheoriesJan 27 2003Apr 11 2003It is shown that the problem of the recursive restoration of the Slavnov-Taylor (ST) identities at the quantum level for anomaly-free gauge theories is equivalent to the problem of parameterizing the local approximation to the quantum effective action ... More
Particles versus fields in PT-symmetrically deformed integrable systemsMar 26 2009We review some recent results on how PT-symmetry, that is a simultaneous time-reversal and parity transformation, can be used to construct new integrable models. Some complex valued multi-particle systems, such as deformations of the Calogero-Moser-Sutherland ... More
PT-symmetry and IntegrabilityAug 17 2007We briefly explain some simple arguments based on pseudo Hermiticity, supersymmetry and PT-symmetry which explain the reality of the spectrum of some non-Hermitian Hamiltonians. Subsequently we employ PT-symmetry as a guiding principle to construct deformations ... More
Supersymmetric integrable scattering theories with unstable particlesNov 11 2004We propose scattering matrices for N=1 supersymmetric integrable quantum field theories in 1+1 dimensions which involve unstable particles in their spectra. By means of the thermodynamic Bethe ansatz we analyze the ultraviolet behaviour of some of these ... More
The anti-hierarchical growth of supermassive black holesFeb 20 2004Jun 28 2004I present a new method to unveil the history of cosmic accretion and the build-up of SMBH in the nuclei of galaxies, based on observations of the evolving radio and (hard) X-ray luminosity functions of AGN. The fundamental plane of black hole activity ... More
High Energy Activity of the Super-Massive Black Hole at the Galactic CenterMay 28 2007The centre of our galaxy hosts the nearest super-massive black hole to the solar system, identified to the compact radio source Sgr A*. High energy experiments have tried in the past to detect the X/gamma-ray emission expected from the accretion of the ... More
Recent results from the Pierre Auger ObservatoryMay 14 2006The goal of the Pierre Auger Observatory is to determine the still unknown nature and origin of ultra-high energy cosmic rays. The study of these elusive particles probes astrophysical sites of particle acceleration as well as fundamental interactions ... More
Removability: First order Sobolev space, PDE solutions, holomorphic functions. - Sobolev space constructed in a new wayJan 23 2004Jan 25 2004Holomorphic removability is of importance in dynanical systems theory. P.W.Jones found that Sobolev removability can serve as a substitute. He proved a strong strong result for H\"older domains. The present work gives some results on the this and related ... More
Superconductivity in an exactly solvable Hubbard model with bond-charge interactionNov 16 1994The Hubbard model with an additional bond-charge interaction $X$ is solved exactly in one dimension for the case $t=X$ where $t$ is the hopping amplitude. In this case the number of doubly occupied sites is conserved. In the sector with no double occupations ... More
Topos Quantum Logic and Mixed StatesApr 20 2010The topos approach to the formulation of physical theories includes a new form of quantum logic. We present this topos quantum logic, including some new results, and compare it to standard quantum logic, all with an eye to conceptual issues. In particular, ... More
The physical interpretation of daseinisationApr 20 2010We provide a conceptual discussion and physical interpretation of some of the quite abstract constructions in the topos approach to physics. In particular, the daseinisation process for projection operators and for self-adjoint operators is motivated ... More
Perspectives for the study of charm in-medium quenching at the LHC with ALICEDec 04 2003Apr 06 2004Charm mesons produced in nucleus-nucleus collisions are expected to be less attenuated (quenched) by the medium than hadrons containing only light quarks, since radiative energy loss of heavy quarks should be reduced by the `dead-cone' effect. We start ... More
Heavy ions and parton saturation from RHIC to LHCDec 09 2008Dec 18 2008The phenomenology of gluon saturation at small parton momentum fraction, Bjorken-x, in the proton and in the nucleus is introduced. The experimentally-accessible kinematic domains at the nucleus-nucleus colliders RHIC and LHC are discussed. Finally, the ... More
Charm quenching in heavy-ion collisions at the LHCJan 31 2005D-meson suppression in Pb-Pb collisions at the LHC due to charm quark in-medium energy loss is estimated within a model that describes the available quenching measurements at RHIC. The result is compared to that previously published by the author. The ... More
Heavy Flavours in Heavy-Ion Collisions at the LHC: ALICE PerformanceMay 13 2004We present the latest results on the ALICE performance for heavy-quark production and quenching measurements, focusing in particular on charm particles.
Probing the QGP with charm at ALICE-LHCJan 05 2004The exclusive reconstruction of D^0 mesons in the ALICE experiment allows to study the QCD energy loss of charm quarks in the deconfined quark-gluon plasma (QGP) medium expected to be produced in central nucleus-nucleus collisions at the Large Hadron ... More
Avoiding another Green Elephant - A Proposal for the Next Generation HLA based on the Model Driven ArchitectureNov 30 2010When looking through the proceedings of the recent Simulation Interoperability Workshops, a lot of papers - some of them even awarded by the committee - are dealing with alternative concepts outside or beyond the High Level Architecture (HLA): Web Services, ... More
Using the C4ISR Architecture Framework as a Tool to Facilitate VV&A for Simulation Systems within the Military Application DomainNov 25 2010To harmonize the individual architectures of the different commands, services, and agencies dealing with the development and procurement of Command, Control, Communications, Computing, Surveillance, Reconnaissance, and Intelligence (C4ISR) systems, the ... More
Exploring the Role of Axions and Other WISPs in the Dark UniverseOct 18 2012Oct 31 2012Axions and other very weakly interacting slim particles (WISPs) may be non-thermally produced in the early universe and survive as constituents of the dark universe. We describe their theoretical motivation and their phenomenology. A huge region in parameter ... More
Searching for axions and ALPs from string theorySep 11 2012We review searches for closed string axions and axion-like particles (ALPs) in IIB string flux compactifications. For natural values of the background fluxes and TeV scale gravitino mass, the moduli stabilisation mechanism of the LARGE Volume Scenario ... More
Particle Interpretations of the PVLAS DataApr 24 2007Recently the PVLAS collaboration reported the observation of a rotation of linearly polarized laser light induced by a transverse magnetic field -- a signal being unexpected within standard QED. In this review, we emphasize two mechanisms which have been ... More
Dynamics of heavy flavor quarks in high energy nuclear collisionsJul 22 2014A general overview on the role of heavy quarks as probes of the medium formed in high energy nuclear collisions is presented. Experimental data compared to model calculations at low and moderate pT are exploited to extract information on the transport ... More
Berezin quantization of noncommutative projective varietiesJun 04 2015Jan 28 2016We show that Berezin quantization works also for noncommutative manifolds. Our main tool is the notion of subproduct systems, which enables all involved objects, such as the Toeplitz operators, to be very conveniently expressed in terms of shift operators ... More
Operator Deformations in Quantum Measurement TheoryApr 09 2013Mar 21 2014We describe rigorous quantum measurement theory in the Heisenberg picture by applying operator deformation techniques previously used in noncommutative quantum field theory. This enables the conventional observables (represented by unbounded operators) ... More
Dequantization via quantum channelsJun 04 2015For a unital completely positive map $\Phi$ ("quantum channel") governing the time propagation of a quantum system, the Stinespring representation gives an enlarged system evolving unitarily. We argue that the Stinespring representations of each power ... More
A Uniform Fixpoint Approach to the Implementation of Inference Methods for Deductive DatabasesAug 27 2011Within the research area of deductive databases three different database tasks have been deeply investigated: query evaluation, update propagation and view updating. Over the last thirty years various inference mechanisms have been proposed for realizing ... More
The Challenge of Modelling Galactic DisksDec 10 2008Dec 12 2008Detailed models of galactic disk formation and evolution require knowledge about the initial conditions under which disk galaxies form, the boundary conditions that affect their secular evolution and the micro-physical processes that drive the multi-phase ... More
Star Formation in Turbulent Molecular CloudsMay 17 2001Recent progress in the understanding of star formation is summarized. A consistent picture is emerging where molecular clouds form with turbulent velocity fields and clumpy substructure, imprinted already during their formation. The clouds are initially ... More
The structure of dark matter halos. Observation versus theoryMar 10 1997The rotation curves of dark matter dominated dwarf galaxies are analysed. The observations show that dark matter halos represent a one-parameter family with self similar density profiles. The global halo parameters, like total mass and scale length are ... More
A model for the infrared emission of FSC 10214+4724Jun 29 2006A model for the infrared emission of the high redshift ultraluminous infrared galaxy FSC 10214+4724 is presented. The model assumes three components of emission: a dusty torus viewed edge-on, clouds that are associated with the narrow-line region and ... More
Surface Plasmons and Topological InsulatorsApr 20 2011May 04 2011We study surface plasmons localized on interfaces between topologically trivial and topologically non-trivial time reversal invariant materials in three dimensions. For the interface between a metal and a topological insulator the magnetic polarization ... More
Evolution studies of the CMS ECAL endcap response and upgrade design options for High-Luminosity LHCSep 10 2014High-Luminosity running at the LHC, which is planned for 2022 and beyond, will imply an order of magnitude increase in radiation levels and particle fluences with respect to the present LHC running conditions. The performance evolution of the CMS electromagnetic ... More
Secondary invariants and the singularity of the Ruelle zeta-function in the central critical pointJan 01 1995The Ruelle zeta-function of the geodesic flow on the sphere bundle $S(X)$ of an even-dimensional compact locally symmetric space $X$ of rank $1$ is a meromorphic function in the complex plane that satisfies a functional equation relating its values in ... More
Vertical transport and domain formation in multiple quantum wellsJan 15 1997In this book article effects related to the vertical transport in weakly coupled multiple quantum wells are reviewed. A self-contained microscopical model for the calculation of the well-to-well currents without any fittings parameters is presented. The ... More