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Results for "J. H. Viehmann"

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VLT L-band mapping of the Galactic Center IRS 3-IRS 13 region Evidence for new Wolf-Rayet type starsJul 07 2005This paper presents L-band ISAAC and NAOS/CONICA (VLT) spectroscopic observations of the IRS~3-IRS~13 Galactic Center region. The ISAAC data allowed us to build the first spectroscopic data cube of the region in the L-band domain corrected for the foreground ... More
Moduli spaces of p-divisible groupsFeb 15 2005Apr 27 2007We study the global structure of moduli spaces of quasi-isogenies of p-divisible groups introduced by Rapoport and Zink. We determine their dimensions and their sets of connected components and of irreducible components. If the isocrystals of the p-divisible ... More
Minimal Newton strata in Iwahori double cosetsMar 05 2019The set of Newton strata in a given Iwahori double coset in the loop group of a reductive group $G$ is indexed by a finite subset of the set $B(G)$ of Frobenius-conjugacy classes. For unramified $G$ we show that it has a unique minimal element and determine ... More
On the geometry of the Newton stratificationNov 10 2015We give an expository overview over recent results on the global structure and geometry of the Newton stratification of the reduction modulo p of Shimura varieties of Hodge type with hyperspecial level structure. More precisely, we discuss non-emptiness, ... More
Truncations of level 1 of elements in the loop group of a reductive groupJul 14 2009Sep 26 2013We generalize the notion of Ekedahl-Oort strata to elements in the loop group of any connected reductive group, and call the resulting discrete invariant the truncation of level 1 of the element. We give conditions for the Newton points occurring among ... More
Set-up for multi coincidence experiments of EUV to VIS photons and charged particles -- the solid angle maximization approachJun 11 2019The coincident detection of particles is a powerful method in experimental physics, enabling the investigation of a variety of projectile-target interactions. The vast majority of coincidence experiments is performed with charged particles, as they can ... More
Moduli spaces of local G-shtukasMar 13 2018We give an overview of the theory of local G-shtukas and their moduli spaces that were introduced in joint work of U.~Hartl and the author, and in the past years studied by many people. We also discuss relations to moduli of global G-shtukas, properties ... More
The dimension of some affine Deligne-Lusztig varietiesMar 28 2006Jul 21 2006We prove Rapoport's dimension conjecture for affine Deligne-Lusztig varieties for GL_h and superbasic b. From this case the general dimension formula for affine Deligne-Lusztig varieties for special maximal compact subgroups of split groups follows, as ... More
Newton strata in the loop group of a reductive groupMay 31 2010May 04 2011We generalize purity of the Newton stratification to purity for a single break point of the Newton point in the context of local G-shtukas respectively of elements of the loop group of a reductive group. As an application we prove that elements of the ... More
Connected components of closed affine Deligne-Lusztig varietiesJul 26 2006Jul 30 2007We determine the set of connected components of closed affine Deligne-Lusztig varieties for special maximal compact subgroups of split connected reductive groups. Especially, we show that such an affine Deligne-Lusztig variety has isolated points if and ... More
The global structure of moduli spaces of polarized p-divisible groupsMar 28 2007We study the global structure of moduli spaces of quasi-isogenies of polarized p-divisible groups introduced by Rapoport and Zink. Using the corresponding results for non-polarized p-divisible groups from a previous paper, we determine their dimensions ... More
Dusty Sources at the Galactic Center: The N- and Q-band view with VISIRJan 19 2006We present mid-infrared N- and Q-band photometry of the Galactic Center from images obtained with the mid-infrared camera VISIR at the ESO VLT in May 2004. The high resolution and sensitivity possible with VISIR enables us to investigate a total of over ... More
L- and M-band imaging observations of the Galactic Center regionNov 30 2004We present near-infrared H-, K-, L- and M-band photometry of the Galactic Center from images obtained at the ESO VLT in May and August 2002, using the NAOS/CONICA (H and K) and the ISAAC (L and M) instruments. The large field of view (70" x 70") of the ... More
VLTI/MIDI measurements of extended mid-infrared emission in the Galactic CenterMay 25 2005We investigated with MIDI the extension of dusty mid-infrared excess sources (IRS 1W, IRS 10W, IRS 2, IRS 8) in immediate vicinity to the black hole (BH) at the GC. We derive 3$\sigma$ upper limits of the correlated fluxes of our target sources which ... More
Dust Embedded Sources at the Galactic Center. 2 to 4$μ$m imaging and spectroscopy in the central parsecJun 07 2004We present the first L-band spectroscopic observations for a dozen stellar sources in the central 0.5 pc of the GC stellar cluster that are bright in the 2-4 micron wavelength domain. With the aid of additional K-band spectroscopic data, we derive optical ... More
The enigma of GCIRS 3 - Constraining the properties of the mid-infrared reference star of the central parsec of the Milky Way with optical long baseline interferometryNov 02 2007Feb 15 2008GCIRS3 is the most prominent MIR source in the central pc of the Galaxy. NIR spectroscopy failed to solve the enigma of its nature. The properties of extreme individual objects of the central stellar cluster contribute to our knowledge of star and dust ... More
A feasibility study of future observations with MIDI and other VLTI science instruments: The example of the Galactic CenterMay 11 2005VLT-Interferometry will allow imaging of the Galactic Center (GC) and the nuclei of extragalactic sources at an angular resolution of a few milliarcseconds. VLTI will be a prime instrument to study the immediate environment of the massive black hole at ... More
On the Hodge-Newton filtration for p-divisible O-modulesOct 23 2007Nov 27 2007The notions Hodge-Newton decomposition and Hodge-Newton filtration for F-crystals are due to Katz and generalize Messing's result on the existence of the local-\'etale filtration for p-divisible groups. Recently, some of Katz's classical results have ... More
Towards a theory of local Shimura varietiesJan 13 2014Jan 17 2014This is a survey article that advertizes the idea that there should exist a theory of p-adic local analogues of Shimura varieties. Prime examples are the towers of rigid-analytic spaces defined by Rapoport-Zink spaces, and we also review their theory ... More
Affine Deligne-Lusztig varieties and the action of JJul 10 2015Sep 14 2016We propose a new stratification of the reduced subschemes of Rapoport-Zink spaces and of affine Deligne-Lusztig varieties that highlights the relation between the geometry of these spaces and the action of the associated automorphism group. We show that ... More
Compact mid-IR sources east of galactic center source IRS5Dec 19 2007There are four less prominent compact sources east of IRS5, the natures of which were unclear until now. We present near-infrared K-band long slit spectroscopy of the four sources east of IRS5 obtained with the ISAAC spectrograph at the ESO VLT in July ... More
Ekedahl-Oort and Newton strata for Shimura varieties of PEL typeNov 14 2010Dec 08 2012We study the Ekedahl-Oort stratification for good reductions of Shimura varieties of PEL type. These generalize the Ekedahl-Oort strata defined and studied by Oort for the moduli space of principally polarized abelian varieties (the "Siegel case"). They ... More
Central leaves in loop groupsJun 30 2016This paper analyses the finer structure of Newton strata in loop groups. These can be decomposed into so-called central leaves. We define them, and determine their global geometric structure. We then study the closure of central leaves, both by proving ... More
The Newton stratification on deformations of local G-shtukasOct 05 2008Feb 11 2010Bounded local G-shtukas are function field analogs for p-divisible groups with extra structure. We describe their deformations and moduli spaces. The latter are analogous to Rapoport-Zink spaces for p-divisible groups. The underlying schemes of these ... More
Irreducible components of minuscule affine Deligne-Lusztig varietiesFeb 27 2017Mar 14 2019We examine the set of $J_b(F)$-orbits in the set of irreducible components of affine Deligne-Lusztig varieties for a hyperspecial subgroup and minuscule coweight $\mu$. Our description implies in particular that its number of elements is bounded by the ... More
Finiteness properties of affine Deligne-Lusztig varietiesFeb 20 2019Affine Deligne-Lusztig varieties are closely related to the special fibre of Newton strata in the reduction of Shimura varieties or of moduli spaces of $G$-shtukas. In almost all cases, they are not quasi-compact. In this note we prove basic finiteness ... More
Irreducible components of minuscule affine Deligne-Lusztig varietiesFeb 27 2017We examine the set of $J_b(F)$-orbits in the set of irreducible components of affine Deligne-Lusztig varieties for a hyperspecial subgroup and minuscule coweight $\mu$. Our description implies in particular that its number of elements is bounded by the ... More
Foliations in deformation spaces of local G-shtukasFeb 11 2010Sep 21 2011We study local G-shtukas with level structure over a base scheme whose Newton polygons are constant on the base. We show that after a finite base change and after passing to an \'etale covering, such a local G-shtuka is isogenous to a completely slope ... More
The generic fiber of moduli spaces of bounded local $G$-shtukasDec 21 2017Moduli spaces of bounded local $G$-shtukas are a group-theoretic generalization of the function field analog of Rapoport and Zink's moduli spaces of $p$-divisible groups. In this article we generalize some very prominent concepts in the theory of Rapoport-Zink ... More
Generalized affine Springer fibersMar 10 2010This paper studies two new kinds of affine Springer fibers that are adapted to the root valuation strata of Goresky-Kottwitz-MacPherson. In addition it develops various linear versions of Katz's Hodge-Newton decomposition.
Generic Newton points and the Newton poset in Iwahori double cosetsFeb 06 2019We consider the Newton stratification on Iwahori double cosets in the loop group of a reductive group. We describe a group-theoretic condition on the generic Newton point, called cordiality, under which the Newton poset (i.e. the index set for non-empty ... More
The Flare Activity of SgrA*; New Coordinated mm to X-Ray ObservationsDec 16 2005We report new simultaneous near-infrared/sub-millimeter/X-ray observations of the SgrA* counterpart associated with the massive 3-4x10**6 solar mass black hole at the Galactic Center. The main aim is to investigate the physical processes responsible for ... More
VLTI observations of IRS~3: The brightest compact MIR source at the Galactic CentreMay 10 2005The dust enshrouded star IRS~3 in the central light year of our galaxy was partially resolved in a recent VLTI experiment. The presented observation is the first step in investigating both IRS~3 in particular and the stellar population of the Galactic ... More
Superradiant Phase Transitions and the Standard Description of Circuit QEDMar 23 2011We investigate the equilibrium behaviour of a superconducting circuit QED system containing a large number of artificial atoms. It is shown that the currently accepted standard description of circuit QED via an effective model fails in an important aspect: ... More
Observing the Nonequilibrium Dynamics of the Quantum Transverse-Field Ising Chain in Circuit QEDAug 07 2012Jan 10 2013We show how a quantum Ising spin chain in a time-dependent transverse magnetic field can be simulated and experimentally probed in the framework of circuit QED with current technology. The proposed setup provides a new platform for observing the nonequilibrium ... More
The quantum transverse-field Ising chain in circuit QED: effects of disorder on the nonequilibrium dynamicsJan 16 2013Apr 19 2013We study several dynamical properties of a recently proposed implementation of the quantum transverse-field Ising chain in the framework of circuit QED. Particular emphasis is placed on the effects of disorder on the nonequilibrium behavior of the system. ... More
Rescaling multipartite entanglement measures for mixed statesSep 05 2011Nov 16 2012A relevant problem regarding entanglement measures is the following: Given an arbitrary mixed state, how does a measure for multipartite entanglement change if general local operations are applied to the state? This question is nontrivial as the normalization ... More
Tight Approximation Bounds for Vertex Cover on Dense k-Partite HypergraphsJul 11 2011We establish almost tight upper and lower approximation bounds for the Vertex Cover problem on dense k-partite hypergraphs.
Reply to Comment on "Superradiant Phase Transitions and the Standard Description of Circuit QED"Feb 14 2012Jun 25 2012A Reply to the Comment by C. Ciuti and P. Nataf [arXiv:1112.0986v1] on our Letter "Superradiant Phase Transitions and the Standard Description of Circuit QED" [Phys. Rev. Lett. 107, 113602 (2011)].
Connected components of affine Deligne-Lusztig varieties in mixed characteristicJul 15 2013Jan 08 2015We determine the set of connected components of minuscule affine Deligne-Lusztig varieties for special maximal compact subgroups of unramified connected reductive groups. Partial results are also obtained for non-minuscule closed affine Deligne-Lusztig ... More
Approximating Subdense Instances of Covering ProblemsOct 30 2010Nov 09 2010We study approximability of subdense instances of various covering problems on graphs, defined as instances in which the minimum or average degree is Omega(n/psi(n)) for some function psi(n)=omega(1) of the instance size. We design new approximation algorithms ... More
A Taxonomy to Assess and Tailor Risk-based Testing in Recent Testing StandardsMay 25 2019This article provides a taxonomy for risk-based testing that serves as a tool to define, tailor, or assess risk-based testing approaches in general and to instantiate risk-based testing approaches for the current testing standards ISO/IEC/IEEE 29119, ... More
Approximating Vertex Cover in Dense HypergraphsDec 12 2010We consider the minimum vertex cover problem in hypergraphs in which every hyperedge has size k (also known as minimum hitting set problem, or minimum set cover with element frequency k). Simple algorithms exist that provide k-approximations, and this ... More
The possibility of detecting Sagittarius A* at 8.6 mumNov 15 2006The Galactic Center was observed at 8.6 mum in order to detect a mid-infrared (MIR) counterpart of Sgr A*, parallel to NIR observations. The goal was to set constraints on possible emission mechanisms.Imaging data were acquired with the adaptive optics ... More
Remarks on the continuum formulation of noncritical stringsDec 01 1992We discuss various aspects of the calculation of correlation functions in conformal theories coupled to quantized 2-dimensional gravity. The main emphasis lies on the construction of a continuation in the number of insertions of the cosmological constant ... More
Remarks on T-duality for open stringsFeb 03 1997This contribution gives in sigma-model language a short review of recent work on T-duality for open strings in the presence of abelian or non-abelian gauge fields. Furthermore, it adds a critical discussion of the relation between RG beta-functions and ... More
A basis of hierarchy of generalized symmetries and their conservation laws for the (3+1)-dimensional diffusion equationDec 06 2017We determine, by hierarchy, dependencies between higher order linear symmetries which occur when generating them using recursion operators. Thus, we deduce a formula which gives the number of independent generalized symmetries (basis) of several orders. ... More
$Q\bar Q$ potential from AdS-CFT relation at $T\geq 0$: Dependence on orientation in internal space and higher curvature correctionsJul 14 1998Sep 15 1998Within the classical approximation we calculate the static $Q\bar Q$ potential via the AdS/CFT relation for nonzero temperature and arbitrary internal orientation of the quarks. We use a higher order curvature corrected target space background. For timelike ... More
Analysis of All Dimensionful Parameters Relevant in Gravitational Dressing of Conformal TheoriesApr 28 1992Starting from a covariant and background independent definition of normal ordered vertex operators we give an alternative derivation of the KPZ relation between conformal dimensions and their gravitational dressed partners. With our method we are able ... More
On Correlation Functions for Non-critical Strings with c<1 but d>1Jun 12 1992We construct a Goulian-Li-type continuation in the number of insertions of the cosmological constant operator which is no longer restricted to one dimensional target space. The method is applied to the calculation of the three-point and a special four-point ... More
Fidelity freeze for a random matrix model with off--diagonal perturbationJan 16 2006The concept of fidelity has been introduced to characterize the stability of a quantum-mechanical system against perturbations. The fidelity amplitude is defined as the overlap integral of a wave packet with itself after the development forth and back ... More
Four Pion Final States with Tagged Photons at Electron Positron CollidersAug 24 2000Oct 11 2000A Monte Carlo generator has been constructed to simulate the reaction e^+e^- \to \gamma + 4 \pi, where the photon is assumed to be observed in the detector. Only initial state radiation is considered. Additional collinear photon radiation has been incorporated ... More
On T-duality for open strings in general abelian and nonabelian gauge field backgroundsMar 28 1996Dec 11 1996We discuss T-duality for open strings in general background fields both in the functional integral formulation as well as in the language of canonical transformations. The Dirichlet boundary condition in the dual theory has to be treated as a constraint ... More
Some conclusions for noncritical string theory drawn from two- and three-point functions in the Liouville sectorJan 06 1995Starting from the known expression for the three-point correlation functions for Liouville exponentials with generic real coefficients at we can prove the Liouville equation of motion at the level of three-point functions. Based on the analytical structure ... More
Two and three-point functions in Liouville theoryMar 23 1994Sep 21 1994Based on our generalization of the Goulian-Li continuation in the power of the 2D cosmological term we construct the two and three-point correlation functions for Liouville exponentials with generic real coefficients. As a strong argument in favour of ... More
Canonical Quantum Supergravity in Three Dimensions, (some lines lost during submission)Jun 15 1993Jun 16 1993We discuss the canonical treatment and quantization of matter coupled supergravity in three dimensions, with special emphasis on $N=2$ supergravity. We then analyze the quantum constraint algebra; certain operator ordering ambiguities are found to be ... More
General Relativistic MHD JetsSep 14 2009Magnetic fields connecting the immediate environs of rotating black holes to large distances appear to be the most promising mechanism for launching relativistic jets, an idea first developed by Blandford and Znajek in the mid-1970s. To enable an understanding ... More
On the PCT--Theorem in the Theory of Local ObservablesDec 11 2000We review the PCT-theorem and problems connected with its demonstration. We add a new proof of the PCT-theorem in the theory of local observables which is similar to that one of Jost in Wightman quantum field theory. We also look at consequences in case ... More
On Wilson loops and $Q\bar Q$-potentials from the AdS/CFT relation at $T\geq 0$Dec 14 1998Jan 15 1999We give a short introduction to and a partial review of the work on the calculation of Wilson loops and $Q\bar Q$-potentials via the conjectured AdS/CFT duality. Included is a discussion of the relative weight of the stringy correction to the target space ... More
Effective Lagrangian for SU(3)_c gluodynamics from lattice color dielectricsMar 19 1998Apr 28 1999Small momenta limit of the lattice color dielectric model in the SU(3)_c case is considered. We show that in that limit the model involves a coarse-grained gluon field, a color singlet "bleached gluon" field, and both color singlet and octet rank two ... More
Invariance analysis, reductions and conservation laws for second-order systems of ordinary difference equationsOct 31 2017We present a method to obtain symmetries for second-order systems of ordinary difference equations and how to use them to reduce the order. We also introduce a technique of finding conservation laws for such systems.
Stripe formation instability in crossing traffic flowsJun 20 2014At the intersection of two unidirectional traffic flows a stripe formation instability is known to occur. In this paper we consider coupled time evolution equations for the densities of the two flows in their intersection area. We show analytically how ... More
Astrometry of brown dwarfs with GaiaApr 15 2014Europe's Gaia spacecraft will soon embark on its five-year mission to measure the absolute parallaxes of the complete sample of 1,000 million objects down to 20 mag. It is expected that thousands of nearby brown dwarfs will have their astrometry determined ... More
Fabrication of Analog Electronics for Serial Readout of Silicon Strip SensorsApr 11 2007Apr 23 2007A set of analog electronics boards for serial readout of silicon strip sensors was fabricated. A commercially available amplifier is mounted on a homemade hybrid board in order to receive analog signals from silicon strip sensors. Also, another homemade ... More
The Solar Photospheric-to-Coronal Fe abundance from X-ray Fluorescence LinesDec 23 2011The ratio of the Fe abundance in the photosphere to that in coronal flare plasmas is determined by X-ray lines within the complex at 6.7~keV (1.9~\AA) emitted during flares. The line complex includes the He-like Fe (\fexxv) resonance line $w$ (6.70~keV) ... More
Avoiding the 4-index transformation in one-body reduced density matrix functional calculations for separable functionalsFeb 10 2016One of the major computational bottlenecks in one-body reduced density matrix (1RDM) functional theory is the evaluation of approximate 1RDM functionals and their derivatives. The reason is that more advanced approximate functionals are almost exclusively ... More
Invertibility of the retarded response functions for initial mixed states: application to one-body reduced density matrix functional theoryJan 05 2016In [J. Chem. Phys. 143, 054102 (2015)] I have derived conditions to characterize the kernel of the retarded response function, under the assumption that the initial state is a ground state. In this article I demonstrate its generalization to mixed states ... More
How the symbol grounding of living organisms can be realized in artificial agentsMar 17 2015A system with artificial intelligence usually relies on symbol manipulation, at least partly and implicitly. However, the interpretation of the symbols - what they represent and what they are about - is ultimately left to humans, as designers and users ... More
Charge independence studied in $NN\to dπ$ reactionsNov 15 2005We review to what extent charge independence breaking (\emph{CIB}) in isospin related reactions of the type $NN\to d\pi$ can or could be seen in existing data. In doing this we present fits to global and threshold cross sections including most recent ... More
Liquid-gas phase transition in finite nuclei within Fermionic Molecular DynamicsJun 02 1998Within Fermionic Molecular Dynamics (FMD) a quantal nuclear system with only 16 nucleons shows a clearly visible liquid-gas phase transition. The FMD model is an approximation to the many-body problem which describes the system by antisymmetrized many-body ... More
A proof of the Kramers degeneracy of transmission eigenvalues from antisymmetry of the scattering matrixMay 21 2008In time reversal symmetric systems with half integral spins (or more concretely, systems with an antiunitary symmetry that squares to -1 and commutes with the Hamiltonian) the transmission eigenvalues of the scattering matrix come in pairs. We present ... More
Tsunami Inflation: Selfconsistent Quantum DynamicsAug 30 2002The physics during the inflationary stage of the universe is of quantum nature involving extremely high energy densities. Moreover, it is out of equilibrium on a fastly expanding dynamical geometry. We complement here the 1999 Chalonge Lectures on out ... More
QCD Analysis of Polarized Deep Inelastic Scattering DataJul 31 2001A QCD analysis of the world data on inclusive polarized deep inelastic scattering of leptons on nucleons is presented in leading and next-to-leading order. New parameterizations are derived for the quark and gluon distributions and the value of $\alpha_s(M_Z)$ ... More
Constraints on $\tanβ$ in SUSY SU(5) GUTMar 29 2002Apr 08 2002On the evaluation of $\tan{\beta}$ is revisited by the method of the renormalization group with the criteria of the bottom-tau unification in the SUSY SU(5) GUT model. Among the conventional supersymmetric theories, an energy-scale constant $M_{SUSY}$ ... More
A Linear Cheeger Inequality using Eigenvector NormsDec 10 2014The Cheeger constant, $h_G$, is a measure of expansion within a graph. The classical Cheeger Inequality states: $\lambda_{1}/2 \le h_G \le \sqrt{2 \lambda_{1}}$ where $\lambda_1$ is the first nontrivial eigenvalue of the normalized Laplacian matrix. Hence, ... More
Strong Energy Condition in $R + R^2$ GravityOct 04 1995In this paper, we study Raychaudhuri's equation in the background of $R + \beta R^2$ gravity with a phenomenological matter ($\rho \propto a(t)^{-n}$). We conclude that even though the Strong Energy Condition (S.E.C.) for Einstein's gravity, which guarantees ... More
Universal QED Corrections to Polarized Electron Scattering in Higher OrdersJul 22 2002We derive QED radiators for the universal corrections to polarized electron scattering. To 5th order in the coupling constant the flavor non-singlet and singlet contributions are calculated. We derive the non-singlet and singlet exponentiation of the ... More
Microcausality and Energy-Positivity in all frames imply Lorentz Invariance of dispersion lawsApr 15 2002A new presentation of the Borchers-Buchholz result of the Lorentz-invariance of the energy-momentum spectrum in theories with broken Lorentz symmetry is given in terms of properties of the Green's functions of microcausal Bose and Fermi-fields. Strong ... More
Coherent-state path integral calculation of the Wigner functionJun 05 2000We consider a set of operators hat{x}=(hat{x}_1,..., hat{x}_N) with diagonal representatives P(n) in the space of generalized coherent states |n>; hat{x}=int dn P(n) |n><n|. We regularize the coherent-state path integral as a limit of a sequence of averages ... More
Heuristic theory for many-faced d-dimensional Poisson-Voronoi cellsJun 24 2009We consider the d-dimensional Poisson-Voronoi tessellation and investigate the applicability of heuristic methods developed recently for two dimensions. Let p_n(d) be the probability that a cell have n neighbors (be `n-faced') and m_n(d) the average facedness ... More
Statistical properties of planar Voronoi tessellationsSep 04 2007Mar 06 2008I present a concise review of advances realized over the past three years on planar Poisson-Voronoi tessellations. These encompass new analytic results, a new Monte Carlo method, and application to experimental data.
New Monte Carlo method for planar Poisson-Voronoi cellsDec 16 2006By a new Monte Carlo algorithm we evaluate the sidedness probability p_n of a planar Poisson-Voronoi cell in the range 3 \leq n \leq 1600. The algorithm is developed on the basis of earlier theoretical work; it exploits, in particular, the known asymptotic ... More
Characterization of entanglement of more than two qubits with Bell inequalities and global entanglementJun 01 2004Aug 16 2004It is shown that the entanglement-structure of 3- and 4-qubit states can be characterized by optimized operators of the Mermin-Klyshko type. It is possible to discriminate between pure 2-qubit entanglements and higher entanglements. A comparison with ... More
The Heidelberg PomeronNov 11 2005Description and understanding of hadronic high energy scattering in the Heidelberg pomeron model
Particle Production and Propagation in NucleiNov 21 2003We discuss the effects of gluon radiation by the struck quark and the subsequent absorption of the produced hadron in deep inelastic lepton-nucleus scattering. The theoretical picture is compared with HERMES results on multiplicity ratios.
Conformally Covariant Differential Operators: Symmetric Tensor FieldsAug 19 1997We extend previous work on conformally covariant differential operators to consider the case of second order operators acting on symmetric traceless tensor fields. The corresponding flat space Green function is explicitly constructed and shown to be in ... More
Long-term Variability Properties and Periodicity Analysis for BlazarsJan 04 2000In this paper, the compiled long-term optical and infrared measurements of some blazars are used to analyze the variation properties and the optical data are used to search for periodicity evidence in the lightcurve by means of the Jurkevich technique ... More
Relation between $γ$-rays and emission lines for the $γ$-ray loud blazarsJul 21 2000The relation between the $\gamma$-ray and the emission line luminosities for a sample of 36 $\gamma$-ray loud blazars is investigated; an apparent correlation between them, $L_{\gamma} \propto L_{Line}^{0.69\pm0.11}$, with a correlation coefficient $r=0.741$ ... More
Is Bayes theorem applicable to all quantum states?May 02 2014Oct 18 2015Reconsidering the already known important question that whether all the axioms and theorems in classical theory of probability are applicable to probability functions in quantum theory, we want to show that the so-called Bayes theorem isn't applicable ... More
Functional Integrals for Correlated ElectronsFeb 24 1994The application of functional integral methods and the Hubbard--Stratonovich transformation to the Hubbard model is discussed. For the attractive case, using a simple gauge transformation of the superconducting order parameter field, the effective action ... More
Topics in Top Quark PhysicsJul 14 1993The status of top quark searches will be briefly reviewed. Theoretical predictions for the top quark decay rate are presented including QCD and electroweak radiative corrections. The possibilities for quarkonium searches at an hadron collider will be ... More
Phase Diagram of Vortices in High-Tc Superconductors from Lattice Defect Model with PinningDec 01 2006Jul 17 2008The theory presented is based on a simple Hamiltonian for a vortex lattice in a weak impurity background which includes linear elasticity and plasticity, the latter in the form of integer valued fields accounting for defects. Within a quadratic approximation ... More
Bose glass and Mott insulator phase in the disordered boson Hubbard modelDec 02 1996Dec 09 1996We study the Villain representation of the two-dimensional disordered boson Hubbard model via Monte Carlo simulations. It is shown that the probability distribution of the local susceptibility has a 1/\chi^2-tail in the Bose glass phase. This gives rise ... More
3-manifolds built from injective handlebodiesJan 30 2006Jan 31 2007This paper looks at a class of closed orientable 3-manifolds constructed from a gluing of three handlebodies, such that the inclusion of each handlebody is $\pi_1$-injective. This construction is the generalisation to handlebodies of the condition for ... More
The DRAT format and DRAT-trim checkerOct 19 2016This document describes the DRAT format for clausal proofs and the DRAT-trim proof checker.
The Bloch Oscillating TransistorMay 12 2003We introduce a new mesoscopic transistor, which consists of a superconducting island connected to superconducting and normal electrodes via two mesoscopic tunnel junctions. Furthermore, the island is being charged through a resistor. The interplay between ... More
Supernova Remnants: acceleration of particles and gamma-ray emissionMay 21 2001Particle acceleration in the dynamically evolving environment of Supernova Remnants is discussed in the framework of a genuinely time-dependent nonlinear theory, assuming spherical symmetry. As a consequence the dependence of injection on the angle between ... More
Light-front gauge propagatorJul 16 2003Jul 25 2004Gauge fields are special in the sense that they are invariant under gauge transformations and they lead to problems when we try quantizing them straightforwardly. To circumvent this problem we need to specify a gauge condition to fix gauge.
Mesoscopic Fermi gas in a harmonic trapOct 09 1997Oct 20 1997We study the thermodynamical properties of a mesoscopic Fermi gas in view of recent possibilities to trap ultracold atoms in a harmonic potential. We focus on the effects of shell closure for finite small atom numbers. The dependence of the chemical potential, ... More
Ward Identity and Basis Tensor Gauge Theory at One LoopDec 29 2017May 11 2018Basis tensor gauge theory (BTGT) is a reformulation of ordinary gauge theory that is an analog of the vierbein formulation of gravity and is related to the Wilson line formulation. To match ordinary gauge theories coupled to matter, the BTGT formalism ... More