Results for "S. Wende-von Berg"

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Fundamental M-dwarf parameters from high-resolution spectra using PHOENIX ACES models: I. Parameter accuracy and benchmark starsJan 08 2016M-dwarf stars are the most numerous stars in the Universe; they span a wide range in mass and are in the focus of ongoing and planned exoplanet surveys. To investigate and understand their physical nature, detailed spectral information and accurate stellar ... More
Non-linear pulsations in Wolf-Rayet starsAug 07 2009Numerical simulations of the evolution of strange-mode instabilities into the non-linear regime have been performed for a wide range of stellar parameters for Wolf-Rayet stars. It has been shown that the Wolf-Rayet models reach radial velocities which ... More
Teff and logg dependence of FeH in M-dwarfsDec 11 2008We present synthetic FeH band spectra in the z-filter range for several M-dwarf models with logg=3.0-5.0 [cgs] and Teff=2800K -3450K. Our aim is to characterize convective velocities in M-dwarfs and to give a rough estimate of the range in which 3D-atmosphere ... More
3D simulations of M star atmosphere velocities and their influence on molecular FeH linesOct 19 2009We present an investigation of the velocity fields in early to late M-type star hydrodynamic models, and we simulate their influence on FeH molecular line shapes. The M star model parameters range between log g of 3.0 - 5.0 and Teff of 2500 K and 4000 ... More
CRIRES spectroscopy and empirical line-by-line identification of FeH molecular absorption in an M dwarfJul 23 2010Molecular FeH provides a large number of sharp and isolated absorption lines that can be used to measure radial velocity, rotation, or magnetic field strength with high accuracy. Our aim is to provide an FeH atlas for M-type stars in the spectral region ... More
Signatures of Majorana Zero Modes in Spin-Resolved Current CorrelationsNov 03 2014Apr 28 2015We consider a normal lead coupled to a Majorana bound state. We show that the spin-resolved current correlations exhibit unique features which distinguish Majorana bound states from other low-energy resonances. In particular, the spin-up and spin-down ... More
Current Correlations in a Majorana Beam SplitterSep 01 2015Dec 15 2015We study current correlations in a $T$-junction composed of a grounded topological superconductor and of two normal-metal leads which are biased at a voltage $V$. We show that the existence of an isolated Majorana zero mode in the junction dictates a ... More
A question by Chihara about shell polynomials and indeterminate moment problemsFeb 14 2011The generalized Stieltjes--Wigert polynomials depending on parameters 0\le p<1 and 0<q<1 are discussed. By removing the mass at zero of the N-extremal solution concentrated in the zeros of the D-function from the Nevanlinna parametrization, we obtain ... More
Magnetic fields in M-dwarfs: quantitative results from detailed spectral synthesis in FeH linesDec 07 2010Strong surface magnetic fields are ubiquitously found in M-dwarfs with mean intensities on the order of few thousand Gauss-three orders of magnitude higher than the mean surface magnetic field of the Sun. These fields and their interaction with photospheric ... More
Deep Learning Based Rib Centerline Extraction and LabelingSep 19 2018Jan 14 2019Automated extraction and labeling of rib centerlines is a typically needed prerequisite for more advanced assisted reading tools that help the radiologist to efficiently inspect all 24 ribs in a CT volume. In this paper, we combine a deep learning-based ... More
Automorphism groups of the finite dimensional special odd Hamiltonian superalgebras in prime characteristicMay 25 2011This paper is devoted to a study of the automorphism groups of three series of finite dimensional special odd Hamiltonian superalgebras $\mathfrak{g}$ over a field of prime characteristic. Our aim is to characterize the connections between the automorphism ... More
On $\mathrm{ID}^{*}$-superderivations of Lie superalgebrasSep 04 2018Let $L$ be a Lie superalgebra over a field of characteristic different from $2, 3$. Write $\mathrm{ID}^{*}(L)$ for the Lie superalgebra consisting of superderivations mapping $L$ to $L^{2}$ and central elements to zero. In this paper we first give an ... More
The minimal number of generators for simple Lie superalgebrasApr 11 2012Using the classification theorem due to Kac we prove that any finite dimensional simple Lie superalgebra over an algebraically closed field of characteristic 0 is generated by one element.
Restricted Kac modules of Hamiltonian Lie superalgebras of odd typeMar 01 2014This paper aims to describe the restricted Kac modules of restricted Hamiltonian Lie superalgebras of odd type over an algebraically closed field of characteristic $p>3$. In particular, a sufficient and necessary condition for the restricted Kac modules ... More
Superderivations for Modular Graded Lie Superalgebras of Cartan-typeJun 16 2011Jun 27 2011Superderivations for the eight families of finite or infinite dimensional graded Lie superalgebras of Cartan-type over a field of characteristic $p>3$ are completely determined by a uniform approach: The infinite dimensional case is reduced to the finite ... More
Hom-Lie superalgebra structures on exceptional simple Lie superalgebras of vector fieldsApr 11 2016In this paper, the Hom-Lie superalgebra structures on exceptional simple Lie superalgebras of vector fields are studied. Taking advantage of the Z-grading structures and the transitivity, we prove that there is only the trivial Hom-Lie superalgebra structures ... More
On cohomology of filiform Lie superalgebrasSep 03 2018Suppose the ground field $\mathbb{F}$ is an algebraically closed field of characteristic different from 2, 3. We determine the Betti numbers and make a decomposition of the associative superalgebra of the cohomology for the model filiform Lie superalgebra. ... More
Classification of nilpotent Lie superalgebras of multiplier-rank $\leq 2$Jul 24 2018In this paper, we introduce the concept of (super-)multiplier-rank for Lie superalgeras and classify all the finite-dimensional nilpotent Lie superalgebras of multiplier-rank $\leq 2$ over an algebraically closed field of characteristic zero. In the process, ... More
Signatures of topological Josephson junctionsApr 14 2016Jul 25 2016Quasiparticle poisoning and diabatic transitions may significantly narrow the window for the experimental observation of the $4\pi$-periodic $dc$ Josephson effect predicted for topological Josephson junctions. Here, we show that switching current measurements ... More
Maximal Subalgebras for Modular Graded Lie Superalgebras of Odd Cartan TypeSep 01 2013Apr 25 2016The purpose of this paper is to determine all maximal graded subalgebras of the four infinite series of finite-dimensional graded Lie superalgebras of odd Cartan type over an algebraically closed field of characteristic $p>3$. All maximal graded subalgebras ... More
Generators of simple modular Lie superalgebrasJul 17 2012Let $X$ be one of the finite-dimensional simple graded Lie superalgebras of Cartan type $W, S, H, K, HO, KO, SHO$ or $SKO$ over an algebraically closed field of characteristic $p>3$. In this paper we prove that $X$ can be generated by one element except ... More
Filtration, automorphisms and classification of the infinite dimensional odd Contact superalgebras superalgebrasJan 04 2010The principal filtration of the infinite-dimensional odd Contact Lie superalgebra over a field of characteristic $p>2$ is proved to be invariant under the automorphism group by investigating ad-nilpotent elements and determining certain invariants such ... More
Finite dimensional special odd contact superalgebras over a field of prime characteristicNov 18 2009This paper considers a family of finite dimensional simple Lie superalgebras of Cartan type over a field of characteristic $p>3$, the so-called special odd contact superalgebras. First, the spanning sets are determined for the Lie superalgebras and their ... More
Derivations for the even parts of modular Lie superalgebras $W$ and $S$ of Cartan typeJul 25 2005Let $\mathbb{F}$ be the underlying base field of characteristic $p>3 $ and denote by $\mathcal{W}$ and $\mathcal{S}$ the even parts of the finite-dimensional generalized Witt Lie superalgebra $W$ and the special Lie superalgebra $S,$ respectively. We ... More
A Systematic Evaluation of Transient Execution Attacks and DefensesNov 13 2018Feb 20 2019Modern CPU optimizations such as branch prediction and out-of-order execution are crucial for performance. Recent research on transient execution attacks including Spectre and Meltdown showed, however, that exception or branch misprediction events may ... More
Bazhanov-Stroganov model from 3D approachMay 07 2005Jul 15 2005We apply a 3-dimensional approach to describe a new parametrization of the L-operators for the 2-dimensional Bazhanov-Stroganov (BS) integrable spin model related to the chiral Potts model. This parametrization is based on the solution of the associated ... More
When does Bone Suppression and Lung Field Segmentation Improve Chest X-Ray Disease Classification?Oct 17 2018Chest radiography is the most common clinical examination type. To improve the quality of patient care and to reduce workload, methods for automatic pathology classification have been developed. In this contribution we investigate the usefulness of two ... More
Universal chiral quasi-steady states in periodically driven many-body systemsMar 09 2016May 01 2016We investigate many-body dynamics in a one-dimensional interacting periodically driven system, based on a partially-filled version of Thouless's topologically quantized adiabatic pump. The corresponding single particle Floquet bands are chiral, with the ... More
Stability of nodal quasi-particles in superconductors with coexisting ordersSep 30 2007Jan 29 2008We establish a condition for the perturbative stability of zero energy nodal points in the quasi-particle spectrum of superconductors in the presence of coexisting \textit{commensurate} orders. The nodes are found to be stable if the Hamiltonian is invariant ... More
Current at a distance and resonant transparency in Weyl semimetalsAug 12 2015Oct 29 2015Surface Fermi arcs are the most prominent manifestation of the topological nature of Weyl semimetals. In the presence of a static magnetic field oriented perpendicular to the sample surface, their existence leads to unique inter-surface cyclotron orbits. ... More
Multiple-line inference of selection on quantitative traitsMay 07 2014Jul 06 2015Trait differences between species may be attributable to natural selection. However, quantifying the strength of evidence for selection acting on a particular trait is a difficult task. Here we develop a population-genetic test for selection acting on ... More
State-dependence of climate sensitivity: attractor constraints and palaeoclimate regimesApr 12 2016Equilibrium climate sensitivity is a frequently used measure to predict long-term climate change. However, both climate models and observational data suggest a rather large uncertainty on climate sensitivity (CS). The reasons for this include: the climate ... More
1D Many-body localized Floquet systems II: Symmetry-Broken phasesFeb 22 2016Recent work suggests that a sharp definition of `phase of matter' can be given for periodically driven `Floquet' quantum systems exhibiting many-body localization. In this work we propose a classification of the phases of interacting Floquet localized ... More
The digital data processing concepts of the LOFT missionAug 27 2014The Large Observatory for X-ray Timing (LOFT) is one of the five mission candidates that were considered by ESA for an M3 mission (with a launch opportunity in 2022 - 2024). LOFT features two instruments: the Large Area Detector (LAD) and the Wide Field ... More
Analytical Solving of Partial Differential Equations using Symbolic ComputingNov 01 1995This work presents a brief discussion and a plan towards the analytical solving of Partial Differential Equations (PDEs) using symbolic computing, as well as an implementation of part of this plan as the PDEtools software-package of commands.
Thermobaric Effect on Melt-Textured MBa$_2$Cu$_3$O$_{7-δ}$ (M = Y, Nd)Jul 04 1999The effect of a short (10-30 min) thermobaric action (in the 1-5 GPa pressure and 700-1300$^\circ$C temperature range) on the structure, superconductive and mechanical properties of melt-textured-MBa$_2$Cu$_3$O$_{7-\delta}$ (M=Y, Nd) or MT-MBCO have been ... More
Moment-volume coupling in La(Fe$_{1-x}$Si$_x$)$_{13}$Aug 28 2017We investigate the origin of the volume change and magnetoelastic interaction observed at the magnetic first-order transition in the magnetocaloric system La(Fe$_{1-x}$Si$_x$)$_{13}$ by means of first-principles calculations combined with the fixed-spin ... More
Associative forms and second cohomologies of Lie superalgebras $HO$ and $KO$Nov 18 2009We consider two families of finite-dimensional simple Lie superalgebras of Cartan type, denoted by HO and KO, over an algebraically closed field of characteristic p>3. Using the weight space decompositions and the principal gradings we first show that ... More
Derivations for the even part of the Hamiltonian superalgebra in positive characteristicOct 26 2005In this paper we consider the derivations for even part of the finite-dimensional Hamiltonian superalgebra $H$ over a field of prime characteristic. We first introduce an ideal $\frak{N}$ of $H_{\bar{0}}$ and show that the derivation space from $H_{\bar{0}}$ ... More
Crystal rules for $(\ell,0)$-JM partitionsJul 19 2011Vazirani and the author \cite{BV} gave a new interpretation of what we called $\ell$-partitions, also known as $(\ell,0)$-Carter partitions. The primary interpretation of such a partition $\lambda$ is that it corresponds to a Specht module $S^{\lambda}$ ... More
Directional superradiant emission from statistically independent incoherent non-classical and classical sourcesMar 25 2014Superradiance is one of the outstanding problems in quantum optics since Dicke introduced the concept of enhanced directional spontaneous emission by an ensemble of identical two-level atoms. The effect is based on correlated collective Dicke states which ... More
Multivariate Lag-Windows and Group RepresentationsDec 22 2006Symmetries of the auto-cumulant function (the generalization of the auto-covariance function) of a kth-order stationary time series are derived through a connection with the symmetric group of degree k. Using theory of group representations, symmetries ... More
The ladder crystalJan 22 2009Jul 19 2011n this paper I introduce a new description of the crystal $B(\Lambda_0)$ of $\hat{\mathfrak{sl}_\ell}$. As in the Misra-Miwa model of $B(\Lambda_0)$, the nodes of this crystal are indexed by partitions and the $i$-arrows correspond to adding a box of ... More
Statistical mechanics of the inverse Ising problem and the optimal objective functionNov 14 2016The inverse Ising problem seeks to reconstruct the parameters of an Ising Hamiltonian on the basis of spin configurations sampled from the Boltzmann measure. Recently, strategies to solve the inverse Ising problem based on convex optimisation have proven ... More
Integral representation of some functions related to the Gamma functionNov 24 2004We prove that the functions Phi(x)=[Gamma(x+1)]^{1/x}(1+1/x)^x/x and log Phi(x) are Stieltjes transforms.
Spectroscopic characterisation of CARMENES target candidates from FEROS, CAFE and HRS high-resolution spectraJul 29 2016CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs) started a new planet survey on M-dwarfs in January this year. The new high-resolution spectrographs are operating in the visible ... More
A two-parameter extension of the Urbanik semigroupFeb 03 2018We prove that s_n(a,b)=\Gamma(an+b)/\Gamma(b), n=0,1,\ldots is an infinitely divisible Stieltjes moment sequence for arbitrary a,b>0. Its powers s_n(a,b)^c, c>0 are Stieltjes determinate if and only if ac\le 2. The latter was conjectured in a paper by ... More
Unraveling the dominant role of phonons in the ultrafast non-local dynamics of a photoexcited metal/insulator heterostructureFeb 14 2019Exploiting the element specificity of soft x-ray spectroscopy, we analyze the microscopic origin of ultrafast non-local dynamics induced by localized optical excitation in metal-insulator heterostructures. The performed ultraviolet pump - soft x-ray probe ... More
Response maxima in modulated turbulenceMay 23 2003Isotropic and homogeneous turbulence driven by an energy input modulated in time is studied within a variable range mean-field theory. The response of the system, observed in the second order moment of the large-scale velocity difference D(L,t)=<<(\u(x+L)-\u(x))^2>>~Re(t)^2$, ... More
Response maxima in modulated turbulence Part II: Numerical simulationsMay 23 2003Numerical simulations of fully developed turbulence driven by a modulated energy input rate or driving force are performed within two dynamical cascade models, the GOY shell model and a reduced wave vector set approximation of the Navier-Stokes equation ... More
Gravitational Lensing by Spinning Black Holes in Astrophysics, and in the Movie InterstellarFeb 12 2015Feb 16 2015Interstellar is the first Hollywood movie to attempt depicting a black hole as it would actually be seen by somebody nearby. For this we developed a code called DNGR (Double Negative Gravitational Renderer) to solve the equations for ray-bundle (light-beam) ... More
On the infrared behaviour of Gluons and Ghosts in Ghost-Antighost symmetric gaugesApr 15 2003Jun 11 2003To investigate the possibility of a ghost-antighost condensate the coupled Dyson--Schwinger equations for the gluon and ghost propagators in Yang--Mills theories are derived in general covariant gauges, including ghost-antighost symmetric gauges. The ... More
Quantum interference and entanglement of photons which do not overlap in timeFeb 08 2011Sep 13 2011We discuss the possibility of quantum interferences and entanglement of photons which exist at different intervals of time, i.e., one photon being recorded before the other has been created. The corresponding two-photon correlation function is shown to ... More
Infrared Exponents and the Running Coupling of Landau gauge QCD and their Relation to ConfinementSep 30 2002The infrared behaviour of the gluon and ghost propagators in Landau gauge QCD is reviewed. The Kugo-Ojima confinement criterion and the Gribov-Zwanziger horizon condition result from quite general properties of the ghost Dyson-Schwinger equation. The ... More
Kugo-Ojima confinement and QCD Green's functions in covariant gaugesJan 15 2003In Landau gauge QCD the Kugo-Ojima confinement criterion and its relation to the infrared behaviour of the gluon and ghost propagators are reviewed. It is demonstrated that the realization of this confinement criterion (which is closely related to the ... More
Chaotic and non-chaotic response to quasiperiodic forcing: limits to predictability of ice ages paced by Milankovitch forcingApr 23 2018Aug 16 2018It is well known that periodic forcing of a nonlinear system, even of a two-dimensional autonomous system, can produce chaotic responses with sensitive dependence on initial conditions if the forcing induces sufficient stretching and folding of the phase ... More
Measuring arbitrary-order coherences: Tomography of single-mode multiphoton polarization-entangled statesAug 12 2009Feb 05 2010A scheme is discussed for measuring Nth-order coherences of two orthogonally polarized light fields in a single spatial mode at very limited experimental cost. To implement the scheme, the only measurements needed are the Nth-order intensity moments after ... More
Measuring the gain dynamics in a conjugated polymer filmFeb 04 2004We present a simple method for measuring the gain decay time in a conjugated polymer film by optically exciting the film with two mutually delayed ultrashort pump pulses. When the pump is set at such a power level that amplified spontaneous emission marginally ... More
Photoluminescence studies study of a phenyl-substituted PPVFeb 04 2004We report on the photophysics of a phenyl-substituted PPV both in solution and as a film. For both systems we have studied the decay of the photoluminescence and of the emission anisotropy for a large set of wavelengths spanning the entire photoluminescence ... More
A Pulsed Synchrotron for Muon Acceleration at a Neutrino FactoryOct 06 2003A 4600 Hz pulsed synchrotron is considered as a means of accelerating cool muons with superconducting RF cavities from 4 to 20 GeV/c for a neutrino factory. Eddy current losses are held to less than a megawatt by the low machine duty cycle plus 100 micron ... More
Quantum Chaos and Regularity in Ultracold Fermi GasesSep 12 2007Quantum fluctuation of the energy is studied for an ultracold gas of interacting fermions trapped in a three-dimensional potential. Periodic-orbit theory is explored, and energy fluctuations are studied versus particle number for generic regular and chaotic ... More
Time-Energy Uncertainty Relations for Neutrino Oscillation and MÖssbauer Neutrino ExperimentMar 04 2008May 19 2008Using the Mandelstam-Tamm method we derive time-energy uncertainty relations for neutrino oscillations. We demonstrate that the small energy uncertainty of antineutrinos in a recently considered experiment with recoilless resonant (M\"ossbauer) production ... More
Gamma strength function and level densities of $^{208}$Pb from forward-angle proton scattering at 295 MeVSep 04 2016Gamma strength functions (GSFs) and level densities (LDs) are essential ingredients of statistical nuclear reaction theory with many applications in astrophysics, reactor design, and waste transmutation. The aim of the present work is a test of systematic ... More
Bimetric Theory and Partial Masslessness with Lanczos-Lovelock Terms in Arbitrary DimensionsDec 18 2012Ghost-free bimetric theories describe nonlinear interactions of massive and massless spin-2 fields and, hence, provide a natural framework for investigating the phenomenon of partial masslessness for massive spin-2 fields at the nonlinear level. In this ... More
Higher Derivative Gravity and Conformal Gravity From Bimetric and Partially Massless Bimetric TheoryMar 27 2013Jul 23 2015In this paper we establish the correspondence between ghost-free bimetric theory and a class of higher derivative gravity actions, including conformal gravity and New Massive Gravity. We also characterize the relation between the respective equations ... More
Analysis of superresolution via 3D structured illumination intensity correlation microscopyJun 02 2018Oct 05 2018Intensity correlation microscopy (ICM), which is prominently known through antibunching microscopy or super-resolution optical fluctuation imaging (SOFI), provides superresolution through a correlation analysis of antibunching of independent quantum emitters ... More
Combining Topological Hardware and Topological Software: Color Code Quantum Computing with Topological Superconductor NetworksApr 05 2017Sep 22 2017We present a scalable architecture for fault-tolerant topological quantum computation using networks of voltage-controlled Majorana Cooper pair boxes, and topological color codes for error correction. Color codes have a set of transversal gates which ... More
The Poincaré-Bendixson Theorem and the Non-linear Cauchy-Riemann EquationsApr 18 2016Fiedler and Mallet-Paret prove a version of the classical Poincar\'e-Bendixson Theorem for scalar parabolic equations. We prove that a similar result holds for bounded solutions of the non-linear Cauchy-Riemann equations. The latter is an application ... More
Neutrino oscillations and uncertainty relationsFeb 14 2011Oct 11 2011We show that coherent flavor neutrino states are produced (and detected) due to the momentum-coordinate Heisenberg uncertainty relation. The Mandelstam-Tamm time-energy uncertainty relation requires non-stationary neutrino states for oscillations to happen ... More
Are Neutrino Oscillations a Non-stationary Phenomenon?Mar 30 2009We discuss different schemes of neutrino oscillations and the time-energy uncertainty relation. From the results of the K2K and MINOS accelerator experiments follows that neutrino oscillations are a non-stationary phenomenon and that the standard time-energy ... More
Peer Grading in a Course on Algorithms and Data Structures: Machine Learning Algorithms do not Improve over Simple BaselinesJun 02 2015Feb 10 2016Peer grading is the process of students reviewing each others' work, such as homework submissions, and has lately become a popular mechanism used in massive open online courses (MOOCs). Intrigued by this idea, we used it in a course on algorithms and ... More
Entanglement of Polarization and Orbital Angular MomentumFeb 06 2015We investigate two-photon entangled states using two important degrees of freedom of the electromagnetic field, namely orbital angular momentum (OAM) and spin angular momentum. For photons propagating in the same direction we apply the idea of $\textit{entanglement ... More
Berry-phase effects in transport through single Jahn-Teller moleculesFeb 21 2007Dec 12 2007The vibrational modes of Jahn-Teller molecules are affected by a Berry phase that is associated with a conical intersection of the adiabatic potentials. We investigate theoretically how this Berry phase affects transport through a single $E \otimes e$ ... More
Operators in Machine Learning: Response Properties in Chemical SpaceJul 23 2018Aug 23 2018The role of response operators is well established in quantum mechanics. We investigate their use for universal quantum machine learning models of response properties in molecules. After introducing a theoretical basis, we present and discuss numerical ... More
A new extensive library of PHOENIX stellar atmospheres and synthetic spectraMar 22 2013Apr 24 2013We present a new library of high-resolution synthetic spectra based on the stellar atmosphere code PHOENIX that can be used for a wide range of applications of spectral analysis and stellar parameter synthesis. The spherical mode of PHOENIX was used to ... More
Element-resolved thermodynamics of magnetocaloric LaFe$_{13-x}$Si$_x$Aug 18 2014Nov 13 2014By combination of two independent approaches, nuclear resonant inelastic X-ray scattering and first-principles calculations in the framework of density functional theory, we determine the element-resolved vibrational density of states in the ferromagnetic ... More
Promising Ferroelectricity in 2D Group IV Tellurides: a First-Principles StudyMay 25 2017Jul 19 2017Based on the first-principles calculations, we investigated the ferroelectric properties of two-dimensional (2D) Group-IV tellurides XTe (X=Si, Ge and Sn), with a focus on GeTe. 2D Group-IV tellurides energetically prefer an orthorhombic phase with a ... More
Maximal Subalgebras for Lie Superalgebras of Cartan TypeApr 20 2013The maximal graded subalgebras for four families of Lie superalgebras of Cartan type over a field of prime characteristic are studied. All maximal reducible graded subalgebras are described completely and their isomorphism classes, dimension formulas ... More
Constraining the Nature of the Galactic Center X-ray Source PopulationSep 26 2005We searched for infrared counterparts to the cluster of X-ray point sources discovered by Chandra in the Galactic Center Region (GCR). While the sources could be white dwarfs, neutron stars, or black holes accreting from stellar companions, their X-ray ... More
Separation of Timescales in a Quantum Newton's CradleJul 22 2015Sep 08 2015For strongly repulsive bosons in one dimension, we provide detailed modeling of the Bragg pulse used in quantum Newton's cradle-like settings or in Bragg spectroscopy experiments. By employing the Fermi-Bose mapping for a finite harmonically trapped gas ... More
Study of the $pd\to ^3\textrm{He} K^+K^-$ and $pd\to ^3\textrm{He} φ$ reactions close to thresholdAug 28 2006Two--kaon production in proton--deuteron collisions has been studied at three energies close to threshold using a calibrated magnetic spectrograph to measure the final $^3$He and a vertex detector to measure the $K^+K^-$ pair. Differential and total cross ... More
Leaf litter decomposition -- Estimates of global variability based on Yasso07 modelJun 04 2009Litter decomposition is an important process in the global carbon cycle. It accounts for most of the heterotrophic soil respiration and results in formation of more stable soil organic carbon (SOC) which is the largest terrestrial carbon stock. Litter ... More
Derivation of an integral of Boros and Moll via convolution of Student t-densitiesSep 14 2010We show that the evaluation of an integral considered by Boros and Moll is a special case of a convolution result about Student t-densities obtained by the authors in 2008.
Linearization coefficients of Bessel polynomialsJun 22 2005We prove positivity results about linearization and connection coefficients for Bessel polynomials. The proof is based on a recursion formula and explicit formulas for the coefficients in special cases. The result implies that the distribution of a convex ... More
On some results of Cufaro Petroni about Student t-processesMar 21 2008This paper deals with Student t-processes as studied in (Cufaro Petroni N 2007 J. Phys. A, Math. Theor. 40(10), 2227-2250). We prove and extend some conjectures expressed by Cufaro Petroni about the asymptotical behavior of a Student t-process and the ... More
P-wave dominance in the pd -> 3He pi+ pi- reaction near threshold measured with the MOMO experiment at COSYDec 24 1998The cross section of the pd -> 3He pi+ pi - reaction has been measured at the MOMO facility in a kinematically complete experiment at a c. m. excess energy of Q = 70 MeV. The energy and angular distributions show that the reaction is dominated by p-wave ... More
Study of the pd(dp) -> 3He pi pi reactions close to thresholdAug 04 2016New experimental data on the pd -> 3He pi+ pi- reaction obtained with the COSY-MOMO detector below the three-pion threshold are presented. The reaction was also studied in inverse kinematics with a deuteron beam and the higher counting rates achieved ... More
On the state dependency of fast feedback processes in (palaeo) climate sensitivityMar 21 2014Apr 30 2014Palaeo data have been frequently used to determine the equilibrium (Charney) climate sensitivity $S^a$, and - if slow feedback processes (e.g. land ice-albedo) are adequately taken into account - they indicate a similar range as estimates based on instrumental ... More
Stochastic resonance between dissipative structures in a bistable noise-sustained dynamicsDec 19 2003We study an extended system that without noise shows a monostable dynamics, but when submitted to an adequate multiplicative noise, an effective bistable dynamics arise. The stochastic resonance between the attractors of the \textit{noise-sustained dynamics} ... More
Simulating Dicke like superradiance with classical light sourcesJun 10 2016In this paper we investigate the close relationship between Dicke superradiance, originally predicted for an ensemble of two-level atoms in entangled states, and the Hanbury Brown and Twiss effect, initially established in astronomy to determine the dimensions ... More
Wick CalculusDec 17 2002In quantum field theory, physicists routinely use "normal ordering" of operators, which just amounts to shuffling all creation operators to the left. Potentially confusing, then, is the occurrence in the literature of normal-ordered functions, sometimes ... More
Effective Action of Matter Fields in Four-Dimensional String OrientifoldsMar 21 2000Apr 03 2000We study various aspects of the Kahler metric for matter fields in N=1,2 orientifold compactifications of type IIB string theory. The result has an infrared-divergent part which reproduces the field- theoretical anomalous dimensions, and a moduli-dependent ... More
An Exact Holographic RG Flow Between 2d Conformal Fixed PointsDec 18 2001Jan 19 2002We describe a supersymmetric RG flow between conformal fixed points of a two-dimensional quantum field theory as an analytic domain wall solution of the three-dimensional SO(4) x SO(4) gauged supergravity. Its ultraviolet fixed point is an N=(4,4) superconformal ... More
Spin-models of granular compaction: From one-dimensional models to random graphsOct 19 2001We discuss two athermal types of dynamics suitable for spin-models designed to model repeated tapping of a granular assembly. These dynamics are applied to a range of models characterised by a 3-spin Hamiltonian aiming to capture the geometric frustration ... More
Re-examining Archie's law: Conductance description by tortuosity and constrictionMar 15 2015In this article we investigate the electrical conductance of an insulating porous medium (e.g., a sedimentary rock) filled with an electrolyte (e.g., brine), usually described using the Archie cementation exponent. We show how the electrical conductance ... More
Signal Confidence Limits from a Neural Network Data AnalysisMar 01 1997May 13 1997This paper deals with a situation of some importance for the analysis of experimental data via Neural Network (NN) or similar devices: Let $N$ data be given, such that $N=N_s+N_b$, where $N_s$ is the number of signals, $N_b$ the number of background events, ... More
Display of probability densities for data from a continuous distributionMay 03 2011Based on cumulative distribution functions, Fourier series expansion and Kolmogorov tests, we present a simple method to display probability densities for data drawn from a continuous distribution. It is often more efficient than using histograms.
Biased Metropolis Sampling for Rugged Free Energy LandscapesJun 24 2003Aug 08 2003Metropolis simulations of all-atom models of peptides (i.e. small proteins) are considered. Inspired by the funnel picture of Bryngelson and Wolyness, a transformation of the updating probabilities of the dihedral angles is defined, which uses probability ... More
Status of the Lambda Lattice Scale for the SU(3) Wilson gauge actionOct 07 2014Jan 31 2015With the emergence of the Yang-Mills gradient flow technique there is renewed interest in the issue of scale setting in lattice gauge theory. Here I compare for the SU(3) Wilson gauge action non-perturbative scale functions of Edwards, Heller and Klassen ... More
Non-deterministic inductive definitionsApr 14 2011Sep 14 2012We study a new proof principle in the context of constructive Zermelo-Fraenkel set theory based on what we will call "non-deterministic inductive definitions". We give applications to formal topology as well as a predicative justification of this principle. ... More