Results for "S. A. Wolf"

total 309824took 0.15s
Debris Disk Radiative Transfer Simulation Tool (DDS)Jun 17 2005A WWW interface for the simulation of spectral energy distributions of optically thin dust configurations with an embedded radiative source is presented. The density distribution, radiative source, and dust parameters can be selected either from an internal ... More
Simple algorithm for computing the communication complexity of quantum communication processesDec 10 2015Feb 29 2016A two-party quantum communication process with classical inputs and outcomes can be simulated by replacing the quantum channel with a classical one. The minimal amount of classical communication required to reproduce the statistics of the quantum process ... More
Quarkonium momentum distributions in photoproduction and B decayJan 10 2000Apr 19 2000According to our present understanding many $J/\psi$ production processes proceed through a coloured $c\bar{c}$ state followed by the emission of soft particles in the quarkonium rest frame. The kinematic effect of soft particle emission is usually a ... More
Supersymmetric Noether Currents and Seiberg-Witten TheoryAug 25 2000The purpose of this paper is twofold. The first purpose is to review a systematic construction of Noether currents for supersymmetric theories, especially effective supersymmetric theories. The second purpose is to use these currents to derive the mass-formula ... More
Electron-lattice interaction and its impact on high Tc superconductivityApr 14 2009In this Colloquium, the main features of the electron-lattice interaction are discussed and high values of the critical temperature up to room temperature could be provided. While the issue of the mechanism of superconductivity in the high Tc cuprates ... More
Signatures of Planets in Spatially Unresolved DisksJun 27 2005Main sequence stars are commonly surrounded by debris disks, composed of cold dust continuously replenished by a reservoir of undetected dust-producing planetesimals. In a planetary system with a belt of planetesimals (like the Solar System's Kuiper Belt) ... More
Communication Complexity of Channels in General Probabilistic TheoriesJan 18 2013Dec 20 2013The communication complexity of a quantum channel is the minimal amount of classical communication required for classically simulating the process of preparation, transmission through the channel, and subsequent measurement of a quantum state. At present, ... More
Efficient radiative transfer in dust grain mixturesSep 13 2002The influence of a dust grain mixture consisting of spherical dust grains with different radii and/or chemical composition on the resulting temperature structure and spectral energy distribution of a circumstellar shell is investigated. The comparison ... More
Spread of the dust temperature distribution in circumstellar disksMay 04 2017Accurate temperature calculations for circumstellar disks are particularly important for their chemical evolution. Their temperature distribution is determined by the optical properties of the dust grains, which, among other parameters, depend on their ... More
The circumstellar disk of HH 30. Searching for signs of disk evolution with multi-wavelength modelingMay 22 2012Circumstellar disks are characteristic for star formation and vanish during the first few Myr of stellar evolution. During this time planets are believed to form in the dense midplane by growth, sedimentation and aggregation of dust. Indicators of disk ... More
Magnetic field geometry of the large globule CB 34Nov 01 2016We report the results of optical polarimetric observations of a Bok globule CB34 to study magnetic field structure on large scales ($10^5-10^6$ AU), which is combined with archival sub-mm observations to characterize the magnetic field structure of CB34 ... More
The T Tauri star RY Tau as a case study of the inner regions of circumstellar dust disksDec 05 2007We study the inner region of the circumstellar disk around the TTauri star RY Tau. Our aim is to find a physical description satisfying the available interferometric data, obtained with the mid-infrared interferometric instrument at the Very Large Telescope ... More
Isotope Effect for the Penetration Depth in SuperconductorsJan 19 1998We show that various factors can lead to an isotopic dependence of the penetration depth $\delta$. Non-adiabaticity (Jahn-Teller crossing) leads to the isotope effect of the charge carrier concentration $n$ and, consequently, of $\delta$ in doped superconductors ... More
The Isotope Effect in SuperconductorsJan 21 1998We review some aspects of the isotope effect (IE) in superconductors. Our focus is on the influence of factors not related to the pairing mechanism. After summarizing the main results obtained for conventional superconductors, we review the effect of ... More
Bose-Einstein Correlations in e+e- -> W+W- at a Linear ColliderJan 11 2000We show that the most popular method to simulate Bose-Einstein (BE) interference effects predicts negligible correlations between identical pions originating from the hadronic decay of different W's produced in e+e- -> W+W- -> 4 jets at typical linear ... More
Galaxy clustering from COMBO-17: The halo occupation distribution at <z>=0.6Jun 14 2005Jun 30 2006We present measurements of galaxy clustering at redshift <z>=0.6 using 10360 galaxies with photometric redshifts over an area of 0.78 square degree from the COMBO-17 survey. To obtain a result that is unaffected by redshift uncertainties, we calculate ... More
Test of the gravitational redshift with stable clocks in eccentric orbits: application to Galileo satellites 5 and 6Aug 25 2015Oct 21 2015The Einstein Equivalence Principle (EEP) is one of the foundations of the theory of General Relativity and several alternative theories of gravitation predict violations of the EEP. Experimental constraints on this fundamental principle of nature are ... More
Negative charge enhancement of near-surface nitrogen vacancy centers by multicolor excitationSep 14 2017Oct 04 2017Nitrogen-Vacancy (NV) centers in diamond have been identified over the past few years as promising systems for a variety of applications, ranging from quantum information science to magnetic sensing. This relies on the unique optical and spin properties ... More
Resonant Raman Study of Superconducting Gap and Electron-Phonon Coupling in YbBa2Cu3O7-deltaAug 19 1999We investigate the electronic background as well as the O2-O3 mode at 330 cm^-1 of highly doped YbBa2Cu3O7-delta in B1g symmetry. Above the critical temperature Tc the spectra consist of an almost constant electronic background and superimposed phononic ... More
Searching for an oscillating massive scalar field as a dark matter candidate using atomic hyperfine frequency comparisonsApr 28 2016Jul 28 2016We use six years of accurate hyperfine frequency comparison data of the dual rubidium and caesium cold atom fountain FO2 at LNE-SYRTE to search for a massive scalar dark matter candidate. Such a scalar field can induce harmonic variations of the fine ... More
Prospects for probing the gluon density in protons using heavy quarkonium hadroproductionOct 05 2001Apr 12 2002We examine carefully bottomonia hadroproduction in proton colliders, especially focusing on the LHC, as a way of probing the gluon density in protons. To this end we develop some previous work, getting quantitative predictions and concluding that our ... More
Tracing planet-induced structures in circumstellar disks using molecular linesMay 21 2015Circumstellar disks are considered to be the birthplace of planets. Specific structures like spiral arms, gaps, and cavities are characteristic indicators of planet-disk interaction. Investigating these structures can provide insights into the growth ... More
Superconductivity-induced changes of the phonon resonances in RBa_2Cu_3O_7 (R=rare earth)Jan 15 2001We observe a characteristic energy $\hbar\omega_{c}\approx 2.1$ eV which separates regions of different behavior of the phonon intensities in the Raman spectra of the $R\rm Ba_2Cu_3O_7$ system. A superconductivity-induced drop of phonon intensities is ... More
Supercurrent through grain boundaries in the presence of strong correlationsJun 28 2011Apr 14 2012Strong correlations are known to severely reduce the mobility of charge carriers near half-filling and thus have an important influence on the current carrying properties of grain boundaries in the high-$T_c$ cuprates. In this work we present an extension ... More
Dynamics of Protein Hydration WaterDec 08 2014We present the frequency- and temperature-dependent dielectric properties of lysozyme solutions in a broad concentration regime, measured at subzero temperatures and compare the results with measurements above the freezing point of water and on hydrated ... More
Bose-Einstein Correlations and Color Reconnection in W-pair productionSep 25 1998We propose a systematic study of Bose-Einstein correlations between identical hadrons coming from different W decays. Experimentally accessible signatures of these correlations as well as of possible color reconnection effects are discussed on the basis ... More
The coolest 'stars' are free-floating planetsJul 29 2014We show that the coolest known object that is probably formed in a star-like mode is a free-floating planet. We discovered recently that the free-floating planetary mass object OTS,44 (M9.5, ~12 Jupiter masses, age ~2 Myr) has significant accretion and ... More
Resistivity and magnetoresistance of FeSe single crystals under Helium-gas pressureMar 26 2015We present temperature-dependent in-plane resistivity measurements on FeSe single crystals under He-gas pressure up to 800 MPa and magnetic fields $B \leq$ 10 T. A sharp phase transition anomaly is revealed at the tetragonal-to-orthorhombic transition ... More
Linking Classical and Quantum Key Agreement: Is There "Bound Information"?May 11 2000After carrying out a protocol for quantum key agreement over a noisy quantum channel, the parties Alice and Bob must process the raw key in order to end up with identical keys about which the adversary has virtually no information. In principle, both ... More
QCD based Calculation of the semi-inclusive Decay η_Q \to γ+ light HadronsJan 17 1997A QCD based calculation of the photon spectrum in semi-inclusive $\eta_Q$ decays is performed. The method applied is an effective theory based on a 1/m_Q expansion of QCD.
Tracing the potential planet-forming regions around seven pre-main-sequence starsMay 05 2009We investigate the nature of the innermost regions of seven circumstellar disks around pre-main-sequence stars. Our object sample contains disks apparently at various stages of their evolution. Both single stars and spatially resolved binaries are considered. ... More
Quantum cryptography on noisy channels: quantum versus classical key-agreement protocolsFeb 11 1999When the 4-state or the 6-state protocol of quantum cryptography is carried out on a noisy (i.e. realistic) quantum channel, then the raw key has to be processed to reduce the information of an adversary Eve down to an arbitrarily low value, providing ... More
Homogenization of the Poisson equation in a non-periodically perforated domainFeb 16 2019We study the Poisson equation in a perforated domain with homogeneous Dirichlet boundary conditions. The size of the perforations is denoted by $\epsilon$ > 0, and is proportional to the distance between neighbouring perforations. In the periodic case, ... More
Impact of an inhomogeneous density distribution on selected observational characteristics of circumstellar disksNov 17 2015Jan 12 2016Context. The analysis of observations of circumstellar disks around young stellar objects is often based on models with a smooth and continuous density distribution. However, spatially resolved observations with increasing angular resolution and dynamical ... More
Effect of dust grain porosity on the appearance of protoplanetary disksJul 24 2014We theoretically analyze protoplanetary disks consisting of porous dust grains. In the analysis of observations of protoplanetary disks the dust phase is often assumed to consist of spherical grains, allowing one to apply the Mie scattering formalism. ... More
Representations on Partially Holomorphic Cohomology Spaces, RevisitedAug 01 2017This is a semi--expository update and rewrite of my 1974 AMS AMS Memoir describing Plancherel formulae and partial Dolbeault cohomology realizations for standard tempered representations for general real reductive Lie groups. Even after so many years, ... More
Infinite Dimensional Multiplicity Free Spaces II: Limits of Commutative NilmanifoldsJan 25 2008We study direct limits $(G,K) = \varinjlim (G_n,K_n)$ of Gelfand pairs of the form $G_n = N_n\rtimes K_n$ with $N_n$ nilpotent, in other words pairs $(G_n,K_n)$ for which $G_n/K_n$ is a commutative nilmanifold. First, we extend the criterion of \cite{W3} ... More
Complex Forms of Quaternionic Symmetric SpacesAug 28 2003Oct 02 2003This is a complete classification of the complex forms of quaternionic symmetric spaces
Cycle Spaces of Infinite Dimensional Flag DomainsSep 10 2015Apr 23 2016Let $G$ be a complex simple direct limit group, specifically $SL(\infty;\mathbb{C})$, $SO(\infty;\mathbb{C})$ or $Sp(\infty;\mathbb{C})$. Let $\mathcal{F}$ be a (generalized) flag in $\mathbb{C}^\infty$. If $G$ is $SO(\infty;\mathbb{C})$ or $Sp(\infty;\mathbb{C})$ ... More
Infinite Dimensional Multiplicity Free Spaces I: Limits of Compact Commutative SpacesJan 25 2008We study direct limits $(G,K) = \varinjlim (G_n,K_n)$ of compact Gelfand pairs. First, we develop a criterion for a direct limit representation to be a multiplicity--free discrete direct sum of irreducible representations. Then we look at direct limits ... More
Solvability, Structure and Analysis for Minimal Parabolic SubgroupsOct 25 2016We examine the structure of the Levi component $MA$ in a minimal parabolic subgroup $P = MAN$ of a real reductive Lie group $G$, work out the cases where $M$ is commutative, verify that $P$ is solvable if and only if $M$ is commutative, and work out the ... More
Aging and communication in the twin paradoxSep 25 2016The twin paradox of the special theory of relativity has given rise to a large body of literature discussing its implications. In its standard form, the traveler changes velocity only at the destination of the trip, so that he appears to perceive an improbably ... More
Stepwise Square Integrability for Nilradicals of Parabolic Subgroups and Maximal Amenable SubgroupsMay 20 2016In a series of recent papers we extended the notion of square integrability, for representations of nilpotent Lie groups, to that of stepwise square integrability. There we discussed a number of applications based on the fact that nilradicals of minimal ... More
Genuine Correlations in Hadronic Z$^0$ DecaysDec 13 2001Correlations among hadrons with the same electric charge produced in Z$^0$ decays are studied using the high statistics data collected from 1991 through 1995 with the OPAL detector at LEP. Normalized factorial cumulants up to fourth order are used to ... More
Search for QCD-instantons at HERAJan 22 2001Signals of QCD instanton induced processes are searched for in deep-inelastic ep scattering at HERA in a kinematic region defined by the Bjorken scaling variables x>0.001, 0.1<y<0.6 and polar angle of the scattered positron >156 degrees. Upper limits ... More
Stepwise Square Integrable Representations: the Concept and Some ConsequencesNov 29 2015There are some new developments on Plancherel formula and growth of matrix coefficients for unitary representations of nilpotent Lie groups. These have several consequences for the geometry of weakly symmetric spaces and analysis on parabolic subgroups ... More
Classical Analysis and Nilpotent Lie GroupsDec 06 2010Classical Fourier analysis has an exact counterpart in group theory and in some areas of geometry. Here I'll describe how this goes for nilpotent Lie groups and for a class of Riemannian manifolds closely related to a nilpotent Lie group structure. There ... More
On the Analytic Structure of Commutative NilmanifoldsJul 01 2014In the classification theorems of Vinberg and Yakimova for commutative nilmanifolds, the relevant nilpotent groups have a very surprising analytic property. The manifolds are of the form $G/K = N \rtimes K/K$ where, in all but three cases, the nilpotent ... More
Stepwise Square Integrability for Nilradicals of Parabolic Subgroups and Maximal Amenable SubgroupsMay 20 2016Feb 15 2017In a series of recent papers we extended the notion of square integrability, for representations of nilpotent Lie groups, to that of stepwise square integrability. There we discussed a number of applications based on the fact that nilradicals of minimal ... More
The Plancherel Formula for Minimal Parabolic SubgroupsJun 27 2013Dec 18 2013In a recent paper we found conditions for a nilpotent Lie group to be foliated into subgroups that have square integrable unitary representations that fit together to form a filtration by normal subgroups. That resulted in explicit character formulae, ... More
Intro To Logarithms After The MeltdownDec 06 2009Mar 02 2010This work is an attempt to 'reconstruct' logarithms in the hypothetical case that mankind has suffered a catastrophe through which all repositories of (mathematical as well as other) knowledge are lost, with the exception of simple arithmetic operations. ... More
Bounded Isometries and Homogeneous QuotientsFeb 15 2015Nov 26 2015In this paper we give an explicit description of the bounded displacement isometries of a class of spaces that includes the Riemannian nilmanifolds. The class of spaces consists of metric spaces (and thus includes Finsler manifolds) on which an exponential ... More
Spherical Functions on Euclidean SpaceSep 20 2005We study special functions on euclidean spaces from the viewpoint of riemannian symmetric spaces. Here the euclidean space $E^n = G/K$ where $G$ is the semidirect product $R^n \cdot K$ of the translation group with a closed subgroup $K$ of the orthogonal ... More
Correlations in e+e- --> W+W- hadronic decaysJan 22 2001A mathematical formalism for the analysis of correlations in multi-source events such as $W^+W^-$ production in $e^+e^-$ annihilations is presented. Various measures used in experimental searches for inter-$W$ correlations are reviewed.
Stepwise Square Integrable Representations for Locally Nilpotent Lie GroupsFeb 16 2014In a recent paper we found conditions for a nilpotent Lie group $N$ to have a filtration by normal subgroups whose successive quotients have square integrable representations, and such that these square integrable representations fit together nicely to ... More
Principal Series Representations of Direct Limit GroupsFeb 17 2004We combine the geometric realization of principal series representations of the author, with the Bott--Borel--Weil Theorem for direct limits of compact groups of Natarajan, Rodriguez-Carrington and the author, obtaining limits of principal series representations ... More
Infinite Dimensional Multiplicity Free Spaces III: Matrix Coefficients and Regular FunctionsSep 09 2009In earlier papers we studied direct limits $(G,K) = \varinjlim (G_n,K_n)$ of two types of Gelfand pairs. The first type was that in which the $G_n/K_n$ are compact Riemannian symmetric spaces. The second type was that in which $G_n = N_n\rtimes K_n$ with ... More
Plancherel Formulae associated to Filtrations of Nilpotent Lie GroupsDec 09 2012Dec 29 2012We study the conditions for a nilpotent Lie group to be foliated into subgroups that have square integrable (relative discrete series) unitary representations, that fit together to form a filtration by normal subgroups. Then we use that filtration to ... More
The BCS-BEC crossover induced by a shallow band: Pushing standard superconductivity types apartMay 05 2016Oct 28 2016It is well-known that the appearance of almost-empty (shallow) conduction bands in solids strongly affects their superconducting properties. In a shallow band charge carriers are depleted and have nearly zero velocities so that the crossover from the ... More
Diffractive scatteringMar 07 2002Mar 18 2002We discuss basic concepts and properties of diffractive phenomena in soft hadron collisions and in deep-inelastic scattering at low Bjorken-x. The paper is not a review of the rapidly developing field but presents an attempt to show in simple terms the ... More
Principal series representations of infinite dimensional Lie groups, II: Construction of induced representationsAug 20 2012Oct 19 2012We study representations of the classical infinite dimensional real simple Lie groups $G$ induced from factor representations of minimal parabolic subgroups $P$. This makes strong use of the recently developed structure theory for those parabolic subgroups ... More
Principal Series Representations of Infinite Dimensional Lie Groups, I: Minimal Parabolic SubgroupsApr 05 2012We study the structure of minimal parabolic subgroups of the classical infinite dimensional real simple Lie groups, corresponding to the classical simple direct limit Lie algebras. This depends on the recently developed structure of parabolic subgroups ... More
Homogeneity for a Class of Riemannian Quotient ManifoldsSep 19 2016We study riemannian coverings $\varphi: \widetilde{M} \to \Gamma\backslash \widetilde{M}$ where $\widetilde{M}$ is a normal homogeneous space $G/K_1$ fibered over another normal homogeneous space $M = G/K$ and $K$ is locally isomorphic to a nontrivial ... More
Solvability, Structure and Analysis for Minimal Parabolic SubgroupsOct 25 2016Jan 22 2017We examine the structure of the Levi component $MA$ in a minimal parabolic subgroup $P = MAN$ of a real reductive Lie group $G$ and work out the cases where $M$ is metabelian, equivalently where $\mathfrak{p}$ is solvable. When $G$ is a linear group we ... More
Unitary Representations, $L^2$ Dolbeault Cohomology, and Weakly Symmetric Pseudo--Riemannian NilmanifoldsOct 12 2018We combine recent developments on weakly symmetric pseudo--riemannian nilmanifolds with with geometric methods for construction of unitary representations on square integrable Dolbeault cohomology spaces. This runs parallel to construction of discrete ... More
Direct frequency comb spectroscopy of trapped ionsDec 22 2008Direct frequency comb spectroscopy of trapped ions is demonstated for the first time. It is shown that the 4s^2S_(1/2)-4p^2P_(3/2) transition in calcium ions can be excited directly with a frequency comb laser that is upconverted to 393 nm. Detection ... More
Storage ring measurement of the C IV recombination rate coefficientJan 31 2001The low energy C IV dielectronic recombination (DR) rate coefficient associated with 2s-2p Delta n=0 excitations of this lithiumlike ion has been measured with high energy-resolution at the heavy-ion storage-ring TSR of the Max-Planck-Institut fuer Kernphysik ... More
Shallow-band superconductors: pushing superconductivity types apartApr 04 2016Magnetic response is a fundamental property of superconducting materials, which helps to distinguish two superconductivity types: the ideally diamagnetic type I and type II, which can develop the mixed state with Abrikosov vortices. We demonstrate that ... More
Experimental Mg IX photorecombination rate coefficientApr 14 2004The rate coefficient for radiative and dielectronic recombination of berylliumlike magnesium ions was measured with high resolution at the Heidelberg heavy-ion storage ring TSR. In the electron-ion collision energy range 0-207 eV resonances due to 2s ... More
Electrode Polarization Effects in Broadband Dielectric SpectroscopyJun 07 2011In the present work, we provide broadband dielectric spectra showing strong electrode polarization effects for various materials, belonging to very different material classes. This includes both ionic and electronic conductors as, e.g., salt solutions, ... More
Multiwavelength interferometric observations and modeling of circumstellar disksMay 13 2013We investigate the structure of the innermost region of three circumstellar disks around pre-main sequence stars HD 142666, AS 205 N, and AS 205 S. We determine the inner radii of the dust disks and, in particular, search for transition objects where ... More
Anomalous temperature evolution of the electronic structure of FeSeFeb 07 2017We present ARPES data taken from the structurally simplest representative of iron-based superconductors, FeSe, in a wide temperature range. Apart from the variations related to the nematic transition, we detect very pronounced shifts of the dispersions ... More
Recent photometry of symbiotic stars - XIIIMar 22 2012We present new multicolour (UBVRcIc) photometric observations of classical symbiotic stars, EG And, Z And, BF Cyg, CH Cyg, CI Cyg, V1329 Cyg, TX CVn, AG Dra, Draco C1, AG Peg and AX Per, carried out between 2007.1 and 2011.9. The aim of this paper is ... More
Critical Phenomena at the Antiferromagnetic Phase Transition of AzuriteJun 04 2012We report on high-resolution acoustic, specific-heat and thermal expansion measurements in the vicinity of the antiferromagnetic phase transition at T_N = 1.88 K on a high-quality single crystal of the natural mineral azurite. A detailed investigation ... More
Reconfigurable Digital Channelizer Design Using Factored Markov Decision ProcessesDec 22 2017In this work, a novel digital channelizer design is developed through the use of a compact, system-level modeling approach. The model efficiently captures key properties of a digital channelizer system and its time-varying operation. The model applies ... More
Polarimetric studies of Comet C/2009 P1 (Garradd)Sep 26 2013We present the optical imaging polarimetric observations of comet C/2009 P1(Garradd) at three different phase angles e.g., 28.2$^\circ$, 28.1$^\circ$ and 21.6$^\circ$. The observations were carried out using IUCAA Faint Object Spectrograph and Camera ... More
Nonlocal transport and heating in superconductors under dual-bias conditionsAug 27 2013Nov 14 2013We report on an experimental and theoretical study of nonlocal transport in superconductor hybrid structures, where two normal-metal leads are attached to a central superconducting wire. As a function of voltage bias applied to both normal-metal electrodes, ... More
Strain-induced enhancement of coercivity in amorphous TbFeCo filmsJun 29 2013We report a strong size dependence of coercivity in amorphous ferrimagnetic TbFeCo films. The as-deposited film exhibited a low saturation magnetization (Ms=100 emu/cc) and a high perpendicular anisotropy (Ku=10^6 erg/cc). Hall-bar devices were fabricated ... More
Dielectronic recombination data for astrophysical applications: Plasma rate-coefficients for Fe^q+ (q=7-10, 13-22) and Ni^25+ ions from storage-ring experimentsFeb 19 2010This review summarizes the present status of an ongoing experimental effort to provide reliable rate coefficients for dielectronic recombination of highly charged iron ions for the modeling of astrophysical and other plasmas. The experimental work has ... More
Structure of the hot object in the symbiotic prototype Z And during its 2000-03 active phaseMar 27 2006Aims: To investigate structure of the hot object in the symbiotic prototype Z And during its major 2000-03 active phase. Methods: Analysis of the far ultraviolet, optical low- and high-resolution spectroscopy and UBVR photometry. Reconstruction of the ... More
Constraining the Evolutionary Stage of Class I Protostars: Multi-wavelength Observations and ModelingAug 17 2005(abridged) We present new Keck images at 0.9 micron and OVRO 1.3 mm continuum images of five Class I protostars in the Taurus star forming region. We analyze these data in conjunction with broadband spectral energy distributions and 8-13 micron spectra ... More
New theoretical approaches for correlated systems in nonequilibriumMay 27 2010We review recent developments in the theory of interacting quantum many-particle systems that are not in equilibrium. We focus mainly on the nonequilibrium generalizations of the flow equation approach and of dynamical mean-field theory (DMFT). In the ... More
An Interferometric Analysis Method for Radio Impulses from Ultra-high Energy Particle ShowersApr 20 2013We present an interferometric technique for the reconstruction of ultra-wide band impulsive signals from point sources. This highly sensitive method was developed for the search for ultra-high energy neutrinos with the ANITA experiment but is fully generalizable ... More
Pristine CNO abundances from Magellanic Cloud B stars I. The LMC cluster NGC 2004 with UVESJan 28 2002We present chemical abundances for four main sequence B stars in the young cluster NGC 2004 in the Large Magellanic Cloud (LMC). Apart from H II regions, unevolved OB-type stars are currently the only accessible source of present-day CNO abundances for ... More
Non-Locality of Experimental Qutrit PairsFeb 20 2014The insight due to John Bell that the joint behavior of individually measured entangled quantum systems cannot be explained by shared information remains a mystery to this day. We describe an experiment, and its analysis, displaying non-locality of entangled ... More
Linking star-formation and enivronment in the A901/902 superclusterDec 04 2003We investigate correlations between the location of galaxies in dense environments and their degree of star-formation activity. Using photometric redshifts and spectral classifications from the unique 17-band COMBO-17 survey we are able to precisely isolate ... More
Tracing accretion variability of high-mass YSOs via light echoesDec 05 2017There is growing evidence for disk-mediated accretion being the dominant mode of star formation across nearly the whole stellar mass spectrum. The stochastic nature of this process has been realized which implies an inherent source variability. It can ... More
Gravitational lens magnification by Abell 1689: Distortion of the background galaxy luminosity functionFeb 01 2000Nov 01 2000Gravitational lensing magnifies the luminosity of galaxies behind the lens. We use this effect to constrain the total mass in the cluster Abell 1689 by comparing the lensed luminosities of background galaxies with the luminosity function of an undistorted ... More
Tests of Lorentz Invariance Using a Microwave Resonator: An UpdateJun 11 2003The frequencies of a cryogenic sapphire oscillator and a hydrogen maser are compared to set new constraints on a possible violation of Lorentz invariance. We determine the variation of the oscillator frequency as a function of its orientation (Michelson-Morley ... More
Probing the Interiors of Very Hot Jupiters Using Transit Light CurvesJul 17 2008Apr 01 2009Accurately understanding the interior structure of extra-solar planets is critical for inferring their formation and evolution. The internal density distribution of a planet has a direct effect on the star-planet orbit through the gravitational quadrupole ... More
Effect of neutron irradiation on the properties of FeSe compound in superconducting and normal statesNov 24 2011Effect of atomic disordering induced by irradiation with fast neutrons on the properties of the normal and superconducting states of polycrystalline samples FeSe has been studied. The irradiation with fast neutrons of fluencies up to 1.25\cdot10^20 cm^-2 ... More
Effect of Magnetic Impurity Correlations on Josephson TunnelingJan 19 1998The ordering trend of magnetic impurities at low temperature results in the frustration of the pair-breaking effect and induces a ``recovery'' of superconducting properties. We show that this effect manifests itself in the deviation of the Josephson current ... More
Collisions and drag in debris discs with eccentric parent beltsApr 26 2017Context: High-resolution images of circumstellar debris discs reveal off-centred rings that indicate past or ongoing perturbation, possibly caused by secular gravitational interaction with unseen stellar or substellar companions. The purely dynamical ... More
Schubert varieties and cycle spacesApr 02 2002Oct 02 2002Complex geometric properties of the orbits of a non-compact real form $G_0$ in a flag manifold $Z=G/Q$ of a complex semi-simple groups $G=G_0^\mathbb C$ are studied. Schubert varieties are used to construct a complex submanifold with optimal slice properties ... More
Dark matter concentrations and a search for cores in Milky Way dwarf satellitesMar 19 2012We investigate the mass distributions within eight classical Milky Way dwarf spheroidal galaxies (MW dSphs) using an equilibrium Jeans analysis and we compare our results to the mass distributions predicted for subhalos in dissipationless \Lambda CDM ... More
Classification of 3-dimensional integrable scalar discrete equationsJun 17 2007Nov 02 2007We classify all integrable 3-dimensional scalar discrete quasilinear equations Q=0 on an elementary cubic cell of the 3-dimensional lattice. An equation Q=0 is called integrable if it may be consistently imposed on all 3-dimensional elementary faces of ... More
Electron-phonon coupling and momentum-dependent electron dynamics in EuFe2As2 using time- and angle-resolved photoemission spectroscopyAug 09 2010Dec 06 2010The Fe pnictide parent compound EuFe2As2 exhibits a strongly momentum dependent carrier dynamics around the hole pocket at the center of the Brillouin zone. The very different dynamics of electrons and holes cannot be explained solely by intraband scattering ... More
Mie Scattering by Ensembles of Particles with Very Large Size ParametersJun 04 2004We present a computer program for the simulation of Mie scattering in case of arbitrarily large size parameters. The elements of the scattering matrix, efficiency factors as well as the corresponding cross sections, the albedo and the scattering asymmetry ... More
The GJ 876 Planetary System -- A Progress ReportJul 21 2004We present an updated analysis of the GJ 876 planetary system based on an augmented data set that incorporates 65 new high-precision radial velocities obtained with the Keck telescope from 2001 to 2004. These new radial velocities permit a more accurate ... More
Local Group Dwarf Spheroidals: Correlated Deviations from the Baryonic Tully-Fisher RelationMar 17 2010Jul 12 2010Local Group dwarf spheroidal satellite galaxies are the faintest extragalactic stellar systems known. We examine recent data for these objects in the plane of the Baryonic Tully-Fisher Relation (BTFR). While some dwarf spheroidals adhere to the BTFR, ... More