Results for "S. Wende-von Berg"

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The CARMENES search for exoplanets around M dwarfs - Photospheric parameters of target stars from high-resolution spectroscopyFeb 08 2018The new CARMENES instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around M dwarfs in the visible and near-infrared regime via the Doppler technique. Characterising our target sample ... More
Teff and log g dependence of velocity fields in M-starsAug 06 2009We present an investigation of velocity fields in early to late M-type hydrodynamic stellar atmosphere models. These velocities will be expressed in classical terms of micro- and macro-turbulent velocities for usage in 1D spectral synthesis. The M-star ... 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
The minimal dimensions of faithful representations for Heisenberg Lie superalgebrasAug 06 2013Apr 25 2016This paper aims to characterize the minimal dimensions and super-dimensions of faithful representations for the Heisenberg Lie superalgebras over an algebraically closed field of characteristic zero.
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
Fractional charges on an integer quantum Hall edgeDec 23 2008May 20 2009We propose ways to create and detect fractionally charged excitations in \emph{integer} quantum Hall edge states. The charge fractionalization occurs due to the Coulomb interaction between electrons propagating on different edge channels. The fractional ... 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
Epitaxial Growth of Large-area Bilayer Graphene on Ru(0001)Jun 04 2014Large-area bilayer graphene (BG) is grown epitaxially on Ru(0001) surface and characterized by low temperature scanning tunneling microscopy. The lattice of the bottom layer of BG is stretched by 1.2%, while strain is absent from the top layer. The lattice ... 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
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
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
Modelling the molecular Zeeman effect in M-dwarfs: methods and first resultsAug 15 2010We present first quantitative results of the surface magnetic field measurements in selected M-dwarfs based on detailed spectra synthesis conducted simultaneously in atomic and molecular lines of the FeH Wing-Ford $F^4\,\Delta-X^4\,\Delta$ transitions. ... 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
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
Derivations from the even parts into the odd parts for Lie superalgebras W and SSep 08 2005Let $\mathcal{W}$ and $\mathcal{S}$ denote the even parts of the general Witt superalgebra $W$ and the special superalgebra $S$ over a field of characteristic $ p>3,$ respectively. In this note, using the method of reduction on $\mathbb{Z}$-gradations, ... More
Generators of simple Lie superalgebras in characteristic 0Mar 22 2011It is shown that any finite dimensional simple Lie superalgebra over an algebraically closed field of characteristic 0 is generated by 2 elements.
Cohomology of Heisenberg Lie SuperalgebrasAug 30 2013Apr 25 2016Suppose the ground field to be algebraically closed and of characteristic different from $2$ and $3$. All Heisenberg Lie superalgebras consist of two super versions of the Heisenberg Lie algebras, $\frak{h}_{2m,n}$ and $\frak{ba}_n$ with $m$ a nonnegative ... More
Maximal graded subalgebras of Witt and Special superalgebrasNov 18 2009Mar 08 2010This paper has been withdrawn by the author due to that the main results and approaches are closedly parallel to the ones in Lie algebra case.
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
Charge $4e$ superconductivity from pair density wave order in certain high temperature superconductorsApr 07 2009Jun 07 2009A number of spectacular experimental anomalies\cite{li-2007,fujita-2005} have recently been discovered in certain cuprates, notably {\LBCO} and {\LNSCO}, which exhibit unidirectional spin and charge order (known as ``stripe order''). We have recently ... More
A dynamically-packed planetary system around GJ667C with three super-Earths in its habitable zoneJun 25 2013Since low-mass stars have low luminosities, orbits at which liquid water can exist on Earth-sized planets are relatively close-in, which produces Doppler signals that are detectable using state-of-the-art Doppler spectroscopy. GJ 667C is already known ... More
Effects of longer-range interactions on unconventional superconductivityNov 13 2011We analyze the effect of the non-vanishing range of electron-electron repulsion on the mechanism of unconventional superconductivity. We present asymptotically exact weak-coupling results for dilute electrons in the continuum and for the 2D extended Hubbard ... 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
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
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
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
The Pin Groups in Physics: C, P, and TDec 06 2000We review the role in physics of the Pin groups, double covers of the full Lorentz group. Pin(1,3) is to O(1,3) what Spin(1,3) is to SO(1,3). The existence of two Pin groups offers a classification of fermions based on their properties under space or ... 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
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
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
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
A new simulation-based model for calculating post-mortem intervals using developmental data for Lucilia sericata (Dipt.: Calliphoridae)Apr 02 2009Mar 30 2010Homicide investigations often depend on the determination of a minimum post-mortem interval (PMI$_{min}$) by forensic entomologists. The age of the most developed insect larvae (mostly blow fly larvae) gives reasonably reliable information about the minimum ... 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.
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.
Reducing the Training Time of Neural Networks by PartitioningNov 10 2015Jan 03 2016This paper presents a new method for pre-training neural networks that can decrease the total training time for a neural network while maintaining the final performance, which motivates its use on deep neural networks. By partitioning the training task ... More
State-dependence of climate sensitivity: attractor constraints and palaeoclimate regimesApr 12 2016Oct 31 2016Equilibrium climate sensitivity (ECS) is a key predictor of climate change. However, it is not very well constrained, either by climate models or by observational data. The reasons for this include strong internal variability and forcing on many time ... More
Single-Solution Hypervolume Maximization and its use for Improving Generalization of Neural NetworksFeb 03 2016This paper introduces the hypervolume maximization with a single solution as an alternative to the mean loss minimization. The relationship between the two problems is proved through bounds on the cost function when an optimal solution to one of the problems ... More
Asymmetric Distributions from Constrained MixturesMar 22 2015This paper introduces constrained mixtures for continuous distributions, characterized by a mixture of distributions where each distribution has a shape similar to the base distribution and disjoint domains. This new concept is used to create generalized ... More
Quasilinear spin voltage profiles in spin thermoelectricsJan 17 2011Recent experiments show that spin thermoelectrics is a promising approach to generate spin voltages. While spin chemical potentials are often limited to a surface layer of the order of the spin diffusion length, we show that thermoelectrically induced ... More
Multiplicative Hom-Lie superalgebra structures on infinite dimensional simple Lie superalgebras of vector fieldsApr 20 2013This paper considers the multiplicative Hom-Lie superalgebra structures on infinite dimensional simple Lie superalgebras of vector fields with characteristic zero. The main result is that there is only the multiplicative Hom-Lie superalgebra structure ... More
Derivations of the finite-dimensional special odd Hamiltonian superalgebrasJul 07 2010The aim is to determine the derivations of the three series of finite-dimensional Z-graded Lie superalgebras of Cartan-type over a field of characteristic p > 3, called the special odd Hamiltonian superalgebras. To that end we first determine the derivations ... More
Investigation of magnetically sensitive FeH linesNov 29 2010M-type stars exhibit strong magnetic fields towards decreasing effective temperatures. The measurement of these fields is complicated due to missing indicators. Molecular FeH lines provide an excellent means to determine magnetic field strengths from ... More
A quantum algorithm for the quantum Schur-Weyl transformMay 17 2012We construct an efficient quantum algorithm to compute the quantum Schur-Weyl transform for any value of the quantum parameter $q \in [0,\infty]$. Our algorithm is a $q$-deformation of the Bacon-Chuang-Harrow algorithm, in the sense that it has the same ... More
Dynamics of gene expression and the regulatory inference problemDec 21 2007Mar 05 2008From the response to external stimuli to cell division and death, the dynamics of living cells is based on the expression of specific genes at specific times. The decision when to express a gene is implemented by the binding and unbinding of transcription ... More
Lagrangian one-particle velocity statistics in a turbulent flowOct 19 2006We present Lagrangian one-particle statistics from the Risoe PTV experiment of a turbulent flow. We estimate the Lagrangian Kolmogorov constant $C_0$ and find that it is affected by the large scale inhomogeneities of the flow. The pdf of temporal velocity ... More
Fibonacci numbers and orthogonal polynomialsSep 11 2006Aug 05 2010We prove that the sequence $(1/F_{n+2})_{n\ge 0}$ of reciprocals of the Fibonacci numbers is a moment sequence of a certain discrete probability, and we identify the orthogonal polynomials as little $q$-Jacobi polynomials with $q=(1-\sqrt{5})/(1+\sqrt{5})$. ... 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
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 Geometric PID Control Framework for Mechanical SystemsOct 14 2016These lectures demonstrate the development of a PID control framework for mechanical systems. Based on the observation that mechanical systems are essentially double integrator systems, we generalize the linear PID controller to mechanical systems that ... More
Complete three photon Hong-Ou-Mandel interference at a three port deviceFeb 10 2015Jun 15 2015We report the possibility of completely destructive interference of three indistinguishable photons on a three port device providing a generalisation of the well known Hong-Ou-Mandel interference of two indistinguishable photons on a two port device. ... More
Measurement induced focussing of radiation from independent single photon sourcesFeb 01 2012We present a technique based on multi-photon detection which leads to a strong focussing of photons scattered by independent single photon emitters. For N single photon sources it is shown that if m - 1 photons are detected in a particular direction (with ... 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
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
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
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
Proof of Consistency of Nonlinear Massive Gravity in the Stuckelberg FormulationMar 23 2012Apr 24 2012We address some recent concerns about the absence of the Boulware-Deser ghost in the Stuckelberg formulation of nonlinear massive gravity. First we provide general arguments for why any ghost analysis in the Stuckelberg formulation has to agree with existing ... 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
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
Superbunching and Nonclassicality as new Hallmarks of SuperradianceNov 03 2015Superradiance, i.e., spontaneous emission of coherent radiation by an ensemble of identical two-level atoms in collective states introduced by Dicke in 1954, is one of the enigmatic problems of quantum optics. The startling gist is that even though the ... 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
Quantized magnetization density in periodically driven systemsOct 12 2016We study micromotion in two-dimensional periodically driven systems in which all bulk Floquet eigenstates are localized by disorder. We show that this micromotion gives rise to a quantized time-averaged magnetization density when the system is filled ... More
Feedback Regularization and Geometric PID Control for Trajectory Tracking of Coupled Mechanical Systems: Hoop Robots on an Inclined PlaneSep 30 2016A hoop robot is the planar version of a spherical robot, and consists of a circular body rolling without slip along a one-dimensional surface, and coupled to one or more of a variety of possible actuating mechanisms. This paper presents a compensator ... More
Stochastic Resonance in Spatially Extended Systems: The Role of Far from Equilibrium PotentialsSep 25 2001Previous works have shown numerically that the response of a ``stochastic resonator'' is enhanced as a consequence of spatial coupling. Also, similar results have been obtained in a reaction-diffusion model by studying the phenomenon of stochastic resonance ... More
Temperature dependence of nonlinear auto-oscillator linewidths: Application to spin-torque nano-oscillatorsJun 25 2008The temperature dependence of the generation linewidth for an auto-oscillator with a nonlinear frequency shift is calculated. It is shown that the frequency nonlinearity creates a finite correlation time, tau, for the phase fluctuations. In the low-temperature ... More
Predicting Stellar Angular SizesNov 08 2013Our survey of long-baseline infrared and optical interferometry measurements is producing considerable numbers of directly determined stellar angular sizes. We use our sample of 124 high-precision (5\%) angular stellar diameter values and correlate them ... More
Extended Weyl Invariance in a Bimetric Model and Partial MasslessnessJul 23 2015Dec 11 2015We revisit a particular ghost-free bimetric model which is related to both partial masslessness (PM) and conformal gravity. Linearly, the model propagates six instead of seven degrees of freedom not only around de Sitter but also around flat spacetime. ... More
On Partially Massless Bimetric GravityAug 09 2012Jul 23 2015We extend the notion of the Higuchi bound and partial masslessness to ghost-free nonlinear bimetric theories. This can be achieved in a simple way by first considering linear massive spin-2 perturbations around maximally symmetric background solutions, ... More
Anomalous Hall effect in a two dimensional electron gas with magnetic impuritiesNov 21 2007Magnetic impurities play an important role in many spintronics-related materials. Motivated by this fact, we study the anomalous Hall effect in the presence of magnetic impurities, focusing on two-dimensional electron systems with Rashba spin-orbit coupling. ... More
Sub-Rayleigh Quantum Imaging Using Single Photon SourcesMay 13 2008We propose a technique capable of imaging a distinct physical object with sub-Rayleigh resolution in an ordinary far-field imaging setup using single-photon sources and linear optical tools only. We exemplify our method for the case of a rectangular aperture ... More
Enhanced bulk-edge Coulomb coupling in Fractional Fabry-Perot interferometersNov 17 2014We study the effects of bulk-edge Coulomb coupling on quantum Hall Fabry-Perot interferometers. We find that these effects can be appreciable in devices which would not usually be associated with strong bulk-edge Coulomb coupling, provided the devices ... 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
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
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
Intensity-intensity correlations as a probe of interferences - under conditions of none in the intensityNov 23 2001The different behaviour of first order interferences and second order correlations are investigated for the case of two coherently excited atoms. For intensity measurements this problem is equivalent to Young's double slit experiment and was investigated ... More
Quantum Coherence in a Single Ion due to strong Excitation of a metastable TransitionOct 05 2000We consider pump-probe spectroscopy of a single ion with a highly metastable (probe) clock transition which is monitored by using the quantum jump technique. For a weak clock laser we obtain the well known Autler-Townes splitting. For stronger powers ... More
Creating path entanglement and violating Bell inequalities by independent photon sourcesJan 21 2010May 18 2010We demonstrate a novel approach of violating position dependent Bell inequalities by photons emitted via independent photon sources in free space. We trace this violation back to path entanglement created a posteriori by the selection of modes due to ... More
On random graphs and the statistical mechanics of granular matterDec 21 2000Oct 19 2001The dynamics of spins on a random graph with ferromagnetic three-spin interactions is used to model the compaction of granular matter under a series of taps. Taps are modelled as the random flipping of a small fraction of the spins followed by a quench ... More
Stochastic differential equations with path-independent solutionsSep 04 2012We present a condition for a stochastic differential equation dX_{t}={\mu}(t,X_{t})dt+{\sigma}(t,X_{t})dB_{t} to have a unique functional solution of the form Z(t,B_{t}). The condition expresses a relation between {\mu} and {\sigma}. A generalization ... More
A determinant characterization of moment sequences with finitely many mass-pointsMay 28 2014To a sequence (s_n)_{n\ge 0} of real numbers we associate the sequence of Hankel matrices \mathcal H_n=(s_{i+j}),0\le i,j \le n. We prove that if the corresponding sequence of Hankel determinants D_n=\det\mathcal H_n satisfy D_n>0 for n<n_0 while D_n=0 ... 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
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.
Mass Transport Phenomena in a MCFC CathodeSep 03 2009A molten carbonate fuel cell (MCFC) is an electro-chemical energy conversion technology that runs on natural gas and employs a molten salt electrolyte. In order to keep the electrolyte in this state, the cell must be kept at a temperature above 500 C, ... 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
Empirical Tests of Zipf's law Mechanism In Open Source Linux DistributionJun 30 2008The evolution of open source software projects in Linux distributions offers a remarkable example of a growing complex self-organizing adaptive system, exhibiting Zipf's law over four full decades. We present three tests of the usually assumed ingredients ... 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
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
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