Results for "Andreas Dengel"

total 13259took 0.20s
Symbol Grounding Association in Multimodal Sequences with Missing ElementsNov 13 2015Jan 12 2016In this paper, we extend a symbolic association framework to being able to handle missing elements in multimodal sequences. The general scope of the work is the symbolic associations of object-word mappings as it happens in language development on infants. ... More
Detection of Anomalies in Large Scale Accounting Data using Deep Autoencoder NetworksSep 15 2017Learning to detect fraud in large-scale accounting data is one of the long-standing challenges in financial statement audits or forensic investigations. Nowadays, the majority of applied techniques refer to handcrafted rules derived from known fraud scenarios. ... More
A Novel Approach for Data-Driven Automatic Site Recommendation and SelectionAug 03 2016This paper presents a novel, generic, and automatic method for data-driven site selection. Site selection is one of the most crucial and important decisions made by any company. Such a decision depends on various factors of sites, including socio-economic, ... More
TSViz: Demystification of Deep Learning Models for Time-Series AnalysisFeb 08 2018This paper presents a novel framework for demystification of convolutional deep learning models for time series analysis. This is a step towards making informed/explainable decisions in the domain of time series, powered by deep learning. There have been ... More
An Evolutionary Algorithm to Learn SPARQL Queries for Source-Target-Pairs: Finding Patterns for Human Associations in DBpediaJul 25 2016Sep 13 2016Efficient usage of the knowledge provided by the Linked Data community is often hindered by the need for domain experts to formulate the right SPARQL queries to answer questions. For new questions they have to decide which datasets are suitable and in ... More
Analysis and Forecasting of Trending Topics in Online Media StreamsMay 29 2014Jun 14 2014Among the vast information available on the web, social media streams capture what people currently pay attention to and how they feel about certain topics. Awareness of such trending topics plays a crucial role in multimedia systems such as trend aware ... More
DeXpression: Deep Convolutional Neural Network for Expression RecognitionSep 17 2015Aug 17 2016We propose a convolutional neural network (CNN) architecture for facial expression recognition. The proposed architecture is independent of any hand-crafted feature extraction and performs better than the earlier proposed convolutional neural network ... More
AudioSentibank: Large-scale Semantic Ontology of Acoustic Concepts for Audio Content AnalysisJul 13 2016Audio carries substantial information about the content of our surroundings. The content has been explored at the semantic level using acoustic concepts, but rarely on concept pairs such as happy crowd and angry crowd. Concept pairs convey unique information ... More
A Generic Method for Automatic Ground Truth Generation of Camera-captured DocumentsMay 04 2016The contribution of this paper is fourfold. The first contribution is a novel, generic method for automatic ground truth generation of camera-captured document images (books, magazines, articles, invoices, etc.). It enables us to build large-scale (i.e., ... More
TSSort: Probabilistic Noise Resistant SortingJun 16 2016In this paper we present TSSort, a probabilistic, noise resistant, quickly converging comparison sort algorithm based on Microsoft TrueSkill. The algorithm combines TrueSkill's updating rules with a newly developed next item pair selection strategy, enabling ... More
Band-edge BCS-BEC crossover in a two-band superconductor: physical properties and detection parametersJul 11 2014Superconductivity in iron-based, magnesium diborides, and other novel superconducting materials has a strong multi-band and multi-gap character. Recent experiments support the possibillity for a BCS-BEC crossover induced by strong-coupling and proximity ... More
Ethemba Trusted Host EnvironmentMainly Based on AttestationJan 28 2009Ethemba provides a framework and demonstrator for TPM applications.
Thermodynamic properties and thermal correlation lengths of a Hubbard model with bond-charge interactionFeb 27 2004We investigate the thermodynamics of a one-dimensional Hubbard model with bond-charge interaction X using the transfer matrix renormalization group method (TMRG). Numerical results for various quantities like spin and charge susceptibilities, particle ... More
Imbalanced thee-component Fermi gas with attractive interactions: Multiple FFLO-pairing, Bose-Fermi and Fermi-Fermi mixtures versus collapse and phase separationJun 04 2009We present a detailed study of the population imbalanced three-component Hubbard chain with attractive interactions. Such a system can be realized experimentally with three different hyperfine states of ultra cold $^6$Li atoms in an optical lattice. We ... More
Classification of maximal transitive prolongations of super-Poincaré algebrasDec 08 2012Jul 22 2014Let $V$ be a complex vector space with a non-degenerate symmetric bilinear form and $\mathbb S$ an irreducible module over the Clifford algebra $Cl(V)$ determined by this form. A supertranslation algebra is a $\mathbb Z$-graded Lie superalgebra $\mathfrak ... More
Super-Poincare' algebras, space-times and supergravities (II)Aug 31 2011The presentation of supergravity theories of our previous paper "Super-Poincare' algebras, space-times and supergravities (I)" is re-formulated in the language of Berezin-Leites-Kostant theory of supermanifolds. It is also shown that the equations of ... More
Equivariant characteristic forms in the Cartan model and Borel equivariant cohomologyAug 31 2015Nov 10 2015We show the compatibility of the differential geometric and the topological construction of equivariant characteristic classes for compact Lie groups. Our analysis motivates a differential geometric construction for equivariant characteristic classes ... More
Status of sub-GeV Hidden Particle SearchesAug 26 2010Hidden sector particles with sub-GeV masses like hidden U(1) gauge bosons, the NMSSM CP-odd Higgs, and other axion-like particles are experimentally little constrained as they interact only very weakly with the visible sector. For masses below the muon ... More
The electroweak chiral Lagrangian reanalyzedJul 09 1999Oct 26 2000In this paper we reanalyze the electroweak chiral Lagrangian with particular focus on two issues related to gauge invariance. Our analysis is based on a manifestly gauge-invariant approach that we introduced recently. It deals with gauge-invariant Green's ... More
Tanaka structures modeled on extended Poincaré algebrasJan 03 2012Oct 04 2012Let (V,(.,.)) be a pseudo-Euclidean vector space and S an irreducible Cl(V)-module. An extended translation algebra is a graded Lie algebra m = m_{-2}+m_{-1} = V+S with bracket given by ([s,t],v) = b(v.s,t) for some nondegenerate so(V)-invariant reflexive ... More
A universal ionization threshold for strongly driven Rydberg statesApr 21 2004We observe a universal ionization threshold for microwave driven one-electron Rydberg states of H, Li, Na, and Rb, in an {\em ab initio} numerical treatment without adjustable parameters. This sheds new light on old experimental data, and widens the scene ... More
Residual Symmetries in the Spectrum of Periodically Driven Alkali Rydberg StatesNov 25 1999We identify a fundamental structure in the spectrum of microwave driven alkali Rydberg states, which highlights the remnants of the Coulomb symmetry in the presence of a non-hydrogenic core. Core-induced corrections with respect to the hydrogen spectrum ... More
The antiferromagnetic spin-1/2 Heisenberg model on the square lattice in a magnetic fieldDec 17 2008Mar 16 2009We study the field dependence of the antiferromagnetic spin-1/2 Heisenberg model on the square lattice by means of exact diagonalizations. In a first part, we calculate the spin-wave velocity, the spin-stiffness, and the magnetic susceptibility and thus ... More
(a,b)-Koszul algebrasJul 20 2010Let $a$ and $b$ be two integers such that $2\le a<b$. In this article we define the notion of $(a,b)$-Koszul algebra as a generalization of $N$-Koszul algebras. We also exhibit examples and we provide a minimal graded projective resolution of the algebra ... More
Gauge-invariant Green's functions for the bosonic sector of the standard modelDec 18 1998Jun 21 2000There are many applications in gauge theories where the usually employed framework involving gauge-dependent Green's functions leads to considerable problems. In order to overcome the difficulties invariably tied to gauge dependence, we present a manifestly ... More
PT-symmetrically deformed shock wavesJan 27 2012We investigate for a large class of nonlinear wave equations, which allow for shock wave formations, how these solutions behave when they are PT-symmetrically deformed. For real solutions we find that they are transformed into peaked solutions with a ... More
Numerical analysis of detection-mechanism models of SNSPDAug 27 2013Nov 12 2013The microscopic mechanism of photon detection in superconducting nanowire single-photon detectors is still under debate. We present a simple, but powerful theoretical model that allows us to identify essential differences between competing detection mechanisms. ... More
Thermodynamics of Deconfined QCD at Small and Large Chemical PotentialAug 31 2004We present large $N_f$ QCD/QED as a test bed for improved pressure calculations, show how to apply the hints obtained on optimized renormalization scales at large $N_f$ to finite $N_f=2$, and compare the results to recent lattice data.
Quantum Corrections to Thermodynamic Properties in the Large $N_f$ Limit of the Quark Gluon PlasmaMay 13 2004In this doctoral thesis we present the exact large $N_f$ calculation at next-to-leading order of the thermal interaction pressure of deconfined QCD for small and large quark chemical potential where the presence of the Landau pole is negligible numerically. ... More
Correspondence Theorems via Tropicalizations of Moduli SpacesJun 08 2014We show that the moduli spaces of irreducible labeled parametrized marked rational curves in toric varieties can be embedded into algebraic tori such that their tropicalizations are the analogous tropical moduli spaces. These embeddings are shown to respect ... More
Rational Dynamical SystemsJan 17 2011We introduce the notion of a rational dynamical system extending the classical notion of a topological dynamical system and we prove (multiple) recurrence results for such systems via a partition theorem for the rational numbers proved by Farmaki and ... More
On the degrees of polynomial divisors over finite fieldsJul 07 2015We show that the proportion of polynomials of degree $n$ over the finite field with $q$ elements, which have a divisor of every degree below $n$, is given by $c_q n^{-1} + O(n^{-2})$. More generally, we give an asymptotic formula for the proportion of ... More
Galois theory for iterative connections and nonreduced Galois groupsDec 21 2007Aug 26 2009This article presents a theory of modules with iterative connection. This theory is a generalisation of the theory of modules with connection in characteristic zero to modules over rings of arbitrary characteristic. We show that these modules with iterative ... More
A trace-like invariant for representations of Hopf algebrasOct 29 2009In this paper we introduce a trace-like invariant for the irreducible representations of a finite dimensional complex Hopf algebra H. We do so by considering the trace of the map induced by the antipode S on the endomorphisms End(V) of a self-dual module ... More
Divisibility Relations for the Dimensions and Hilbert series of Nichols Algebras of Non-Abelian Group TypeJun 28 2012We present a divisibility relation for the dimensions and Hilbert series of certain classes of Nichols algebras of non-abelian group type, which generalizes Nichols algebras over Coxeter groups with constant cocycle -1. For this we introduce three groups ... More
Stone spectra of von Neumann algebras of type $I_{n}$Jan 18 2005The Stone spectrum of a von Neumann algebra is a generalization of the Gelfand spectrum, as was shown by de Groote. In this article we clarify the structure of the Stone spectra of von Neumann algebras of type $I_{n}$.
Almost CR quaternionic manifolds and their immersibility in HP^nNov 16 2013Oct 20 2016We apply the general theory of codimension one integrability conditions for $G$-structures developed in arXiv:1306.6817v3 [math.DG] to the case of quaternionic CR geometry. We obtain necessary and sufficient conditions for an almost CR quaternionic manifold ... More
Sur l'effectivite du theoreme de Siegel et la conjecture abcJan 19 2005Apr 23 2006Nous montrons qu'un raffinement du th\'eor\`eme de Siegel sur les points entiers de courbes alg\'ebriques impliquerait la conjecture abc de Masser-Oesterl\'e. Nous formulons une hypoth\`ese "Siegel uniforme" qui est une majoration de la hauteur des points ... More
Metha-Ramanathan for ε and k-semistable Decorated SheavesDec 27 2013This paper is devoted to generalizing the Mehta-Ramanathan restriction theorem to the case of {\epsilon}-semistable and k-semistable decorated sheaves. After recalling the definition of decorated sheaves and their usual semistability we define the {\epsilon} ... More
Correlation of internal representations in feed-forward neural networksApr 11 1996Feed-forward multilayer neural networks implementing random input-output mappings develop characteristic correlations between the activity of their hidden nodes which are important for the understanding of the storage and generalization performance of ... More
Laboratory Studies of Astrophysical JetsMar 02 2009Jets and outflows produced during star-formation are observed on many scales: from the "micro-jets" extending a few hundred Astronomical Units to the "super-jets" propagating to parsecs distances. Recently, a new "class" of short-lived (hundreds of nano-seconds) ... More
Status of the global electroweak fit of the Standard ModelSep 07 2009Sep 09 2009Results from the global Standard Model fit to electroweak precision data, including newest Tevatron measurements, are reviewed and discussed. The complete fit using also the constraints from the direct Higgs boson searches yields an upper limit on the ... More
The finite infinite range Heisenberg model and microcanonical black hole statisticsFeb 03 2015Jan 21 2016The Gelfand pattern of the reduction of the N-fold tensor product of the fundamental representation of the special unitary group SU(2) by itself is studied in the framework of a finite Heisenberg model with infinite range, where N spins couple to each ... More
The position of the quasielastic peak and electron Coulomb distortion in (e,e') scatteringNov 29 2006The position of the quasielastic peak for (e,e') scattering off 208-Pb extracted from a selected data set measured at Saclay is related to a heuristic theoretical description. An analysis of the data shows that the peak position can be described very ... More
Causal construction of the massless vertex diagramJul 17 2006Sep 28 2006The massless one-loop vertex diagram is constructed by exploiting the causal structure of the diagram in configuration space, which can be translated directly into dispersive relations in momentum space.
Perturbative quantum gauge invariance: Where the ghosts come fromJan 23 2004Oct 07 2004A condensed introduction to quantum gauge theories is given in the perturbative S-matrix framework; path integral methods are used nowhere. This approach emphasizes the fact that it is not necessary to start from classical gauge theories which are then ... More
Fock Vacuum Instability and CausalityApr 02 2001Apr 04 2001The vacuum diagram is calculated at second order for theories with self-interacting massless fields in the framework of finite causal perturbation theory. It is pointed out that the infrared behaviour of the vacuum diagram leads to unstable Fock vacua ... More
Twisted cotangent sheaves and a Kobayashi-Ochiai theorem for foliationsJul 12 2013Let X be a normal projective variety, and let A be an ample Cartier divisor on X. We prove that the twisted cotangent sheaf \Omega_X \otimes A is generically nef with respect to the polarisation A unless X is a projective space. As an application we prove ... More
Tauonic $B$ decays and Higgs mediated flavour violationOct 30 2014Nov 05 2014In these proceedings we review the impact of the tauonic $B$ decays $B\to\tau\nu$, $B\to D\tau\nu$ and $B\to D^*\tau\nu$ on Higgs mediated flavour violation. For this purpose we study a 2HDM with generic flavour structure (of type III). We find that despite ... More
Chiral Enhancement in the MSSM -- An OverviewJun 06 2011In this article I review the origin and the effects of chirally enhanced loop-corrections in the MSSM based on Refs. [1-3]. Chiral enhancement is related to fermion-Higgs couplings (or self-energies when the Higgs field is replaced by its vev). I describe ... More
Effective Higgs Vertices in the generic MSSMDec 21 2010Jun 12 2012In this article we consider chirally enhanced corrections to Higgs vertices in the most general MSSM. We include the contributions stemming from bilinear-terms, from the trilinear A-terms and their non-holomorphic analogues, the A'-terms, which couple ... More
Charged Higgs: Interpretation of $B$-physics resultsDec 08 2014In these proceedings we review the impact of additional Higgs bosons on $B$ physics observables. For this purpose, we consider first the 2HDM of type II which respects natural flavour conservation. Afterwards, we study a 2HDM with generic flavour structure ... More
Rare decays and MSSM phenomenologyMay 22 2012In this article I review some aspects of flavour phenomenology in the MSSM. After an overview of various flavour observables I discuss the constraints on the off-diagonal elements of the squark mass matrices. In this context I present the Fortran code ... More
Chirally enhanced corrections in the MSSMJul 18 2011In the general MSSM, chirally-enhanced corrections (to Yukawa couplings) are induced by gluino-squark, chargino-sfermion and neutralino-sfermion loops and can numerically compete with, or even dominate over, tree-level contributions, due to their chiral ... More
Relaxation phenomena at criticalityDec 07 2007The collective behaviour of statistical systems close to critical points is characterized by an extremely slow dynamics which, in the thermodynamic limit, eventually prevents them from relaxing to an equilibrium state after a change in the thermodynamic ... More
Chameleonic dilaton and conformal transformationsJun 20 2012We recently proposed a chameleonic solution to the cosmological constant problem - Phys. Rev. D82 (2010) 044006. One of the results of that paper is a non-equivalence of different conformal frames at the quantum level. In this letter we further discuss ... More
Chameleonic dilaton, nonequivalent frames, and the cosmological constant problem in quantum string theoryJul 31 2010The chameleonic behaviour of the String theory dilaton is suggested. Some of the possible consequences of the chameleonic string dilaton are analyzed in detail. In particular, (1) we suggest a new stringy solution to the cosmological constant problem ... More
Dilaton stabilization and composite dark matter in the string frame of heterotic-M-theoryOct 14 2012In this paper we further elaborate on our recently proposed solution to the cosmological constant problem - Phys. Rev. D82 (2010) 044006. One of the elements of the solution is the chameleonic behaviour of the Einstein frame dilaton: the mass of the dilaton ... More
Yang-Mills connections of cohomogeneity one on SO(n)-bundles over Euclidean spheresJul 29 2011We construct Yang-Mills connections on SO(n)-bundles over spheres equipped with the Euclidean metric. We use a cohomogeneity one group action on the bundle to reduce the Yang-Mills-equation to a system of ordinary differential equations. The system is ... More
Microstructure Effects on Daily Return Volatility in Financial MarketsNov 17 2000We simulate a series of daily returns from intraday price movements initiated by microstructure elements. Significant evidence is found that daily returns and daily return volatility exhibit first order autocorrelation, but trading volume and daily return ... More
Non-linear Oscillations of Compact Stars and Gravitational WavesJul 31 2006This thesis investigates in the time domain a particular class of second order perturbations of a perfect fluid non-rotating compact star: those arising from the coupling between first order radial and non-radial perturbations. This problem has been treated ... More
The special function "shin", IIJan 05 2005Sep 09 2013This Paper (one first and draft version) contains some small imperfections, one its correct and definitive version has been already submitted to one prestigious review of mathematics. More precisely "the Special Function SHIN, II" will be published in ... More
Cellular Automaton Approach to Pedestrian Dynamics - TheoryDec 07 2001We present a 2-dimensional cellular automaton model for the simulation of pedestrian dynamics. The model is extremely efficient and allows simulations of large crowds faster than real time since it includes only nearest-neighbour interactions. Nevertheless ... More
A dynamical model of non regulated marketsJul 15 1999The main focus of this work is to understand the dynamics of non regulated markets. The present model can describe the dynamics of any market where the pricing is based on supply and demand. It will be applied here, as an example, for the German stock ... More
A critical analysis of the hydrino modelMay 20 2005Recently, spectroscopic and calorimetric observations of hydrogen plasmas and chemical reactions with them have been interpreted as evidence for the existence of electronic states of the hydrogen atom with a binding energy of more than 13.6 eV. The theoretical ... More
Testing for the Pioneer anomaly on a Pluto exploration missionSep 15 2004The Doppler-tracking data of the Pioneer 10 and 11 spacecraft show an unmodelled constant acceleration in the direction of the inner Solar System. An overview of the phenomenon, commonly dubbed the Pioneer anomaly, is given and the possibility for an ... More
On recursion relations in topological string theoryOct 16 2012Jan 22 2013We discuss a link between the topological recursion relations derived algebraically by Witten and the holomorphic anomaly equation of Bershadsky, Cecotti, Ooguri and Vafa. This is obtained through the definition of an operator ${\cal{W}}_s$ that reproduces ... More
A perturbative study on the analytic continuation for generalized gravitational entropyDec 02 2014Dec 15 2014We study the analytic continuation used by Lewkowycz and Maldacena to prove the Ryu-Takayanagi formula for entanglement entropy, which is the holographic dual of the trace of the $\beta$-power of the time evolution operator when $\beta\in \mathbb{R}$. ... More
Double genus expansion for general $Ω$ backgroundApr 11 2012Jun 23 2012We will show how the refined holomorphic anomaly equation obeyed by the Nekrasov partition function at generic $\epsilon_1,\epsilon_2$ values becomes compatible, in a certain two parameters expansion, with the assumption that both parameters are associated ... More
Variation on a Theorem by Mues and SteinmetzMar 04 2013Let $f$ be a meromorphic function. We suggest a generalization of $f$ and its derivative $f'$ sharing a nonzero value $a$ IM that does not impose any a priori restrictions on the ramification of $f$. Then we discuss some results around the question whether ... More
PT-symmetric deformations of integrable modelsApr 10 2012We review recent results on new physical models constructed as PT-symmetrical deformations or extensions of different types of integrable models. We present non-Hermitian versions of quantum spin chains, multi-particle systems of Calogero-Moser-Sutherland ... More
Slavnov-Taylor parameterization of Yang-Mills theory with massive fermions in the presence of singlet axial-vector currentsApr 08 2005Jul 18 2005We study the all-order restoration of the Slavnov-Taylor (ST) identities for Yang-Mills theory with massive fermions in the presence of singlet axial-vector currents. By making use of the ST parameterization of the symmetric quantum effective action a ... More
The Algebra of Physical Observables in Nonlinearly Realized Gauge TheoriesJul 23 2010We classify the physical observables in spontaneously broken nonlinearly realized gauge theories in the recently proposed loopwise expansion governed by the Weak Power-Counting (WPC) and the Local Functional Equation. The latter controls the non-trivial ... More
A chain rule for the expected suprema of Gaussian processesNov 10 2014The expected supremum of a Gaussian process indexed by the image of an index set under a function class is bounded in terms of separate properties of the index set and the function class. The bound is relevant to the estimation of nonlinear transformations ... More
An optimization problem on the sphereMay 15 2008We prove existence and uniqueness of the minimizer for the average geodesic distance to the points of a geodesically convex set on the sphere. This implies a corresponding existence and uniqueness result for an optimal algorithm for halfspace learning, ... More
Centroid bodies and the convexity of area functionalsMay 07 2013Oct 21 2013We introduce a new volume definition on normed vector spaces. We show that the induced $k$-area functionals are convex for all $k$. In the particular case $k=2$, our theorem implies that Busemann's 2-volume density is convex, which was recently shown ... More
Where the Wild Things Are: Observational Constraints on Black Holes' GrowthSep 11 2009The physical and evolutionary relation between growing supermassive black holes (AGN) and host galaxies is currently the subject of intense research activity. Nevertheless, a deep theoretical understanding of such a relation is hampered by the unique ... More
The fundamental plane of black hole activity and the census of the local black holes' populationJan 08 2004Studying a sample of both strongly and weakly active galactic nuclei with measured masses and 5 GHz and 2-10 keV core luminosities, together with a few galactic black holes simultaneously observed in the radio and X-ray bands, Merloni, Heinz, & Di Matteo ... More
Discrete LIBOR Market Model AnalogyAug 22 2011Jun 07 2012This paper provides a discrete time LIBOR analog, which can be used for arbitrage-free discretization of Levy LIBOR models or discrete approximation of continuous time LIBOR market models. Using the work of Eberlein and Oezkan as an inspiration, we build ... More
Poincaré inequalities for mutually singular measuresMar 20 2014Using an inverse system of metric graphs as in: J. Cheeger and B. Kleiner, "Inverse limit spaces satisfying a Poincar\'e inequality", we provide a simple example of a metric space $X$ that admits Poincar\'e inequalities for a continuum of mutually singular ... More
Dynamical R-parity violations from exotic instantonsMay 04 2015Apr 06 2016We show how R-parity can be dynamically broken by non-perturbative quantum gravity effects. In particular, in D-brane models, Exotic instantons provide a simple and calculable mechanism for the generation of R-parity violating bilinear, trilinear and ... More
Direct generation of a Majorana mass for the Neutron from Exotic InstantonsJun 21 2015Apr 06 2016We discuss a new mechanism in which non-perturbative quantum gravity effects directly generate a Majorana mass for the neutron. In particular, in string theory, exotic instantons can generate an effective six quark operator by calculable mixed disk amplitudes. ... More
'Exotic vector-like pair' of color-triplet scalarsJan 19 2015Apr 26 2015We propose a minimal extension of Standard Model, generating a Majorana mass for neutron, connected with a mechanism of Post-Sphaleron Baryogenesis. We consider an `exotic vector-like pair' of color-triplet scalars, an extra Majorana fermion $\psi$, and ... More
Charm and beauty at the LHCSep 27 2006Sep 29 2006The Large Hadron Collider at CERN will open a new energy domain for heavy-ion physics. Besides ALICE, the dedicated heavy-ion experiment, also ATLAS and CMS are preparing rich physics programs with nucleus-nucleus collisions. Here we focus on open heavy-flavour ... More
Charm production and in-medium QCD energy loss in nucleus-nucleus collisions with ALICE. A performance studyNov 03 2003Dec 16 2003This work is aimed at studying the performance of the ALICE detector for measuring charm production in heavy ion collisions at the LHC and for investigating the properties of the deconfined quark-gluon medium formed in central nucleus-nucleus reactions ... More
Multi-W(Z) Production in High-Energy Collisions?May 18 1993There exists the possibility that the cross-section for the nonperturbative production of many, ${\cal O}(\alpha_W^{-1} \simeq 30 )$, weak gauge bosons may be as large as ${\cal O}(100\ {\rm pb}\ -\ 10\ \mu$b$)$ above a parton-parton center-of-mass threshold ... More
Axion interpretation of the PVLAS data?Nov 15 2005The PVLAS collaboration has recently reported the observation of a rotation of the polarization plane of light propagating through a transverse static magnetic field. Such an effect can arise from the production of a light, m_A ~ meV, pseudoscalar coupled ... More
First Observation of the Sigma_c^{*+} Charmed Baryon, and New Measurements of the Sigma_c^0, Sigma_c^+, Sigma_c^{++}, and Omega_c^0 Charmed BaryonsSep 15 2000Oct 18 2000Using ~13.7 fb^{-1} of e^+e^- collision data recorded at near the Upsilon(4S) resonance by the CLEO II and CLEO II.V detector configurations on the Cornell Electron Storage Ring, we present the world's most precise measurements of the Sigma_c^0, Sigma_c^+, ... More
Decays of B_s Mesons and b Baryons: A Review of Recent First Observations and Branching FractionsJun 27 2008Jun 28 2008Recent rate measurements of B_s mesons and Lambda_b baryons produced in sqrt{s} = 1.96 TeV proton-antiproton and Upsilon(5S) electron-positron collisions are reviewed, including the first observations of six new decay modes: B_s -> D_s^+ K^- (CDF), B_s ... More
Branching Fractions and CP Asymmetries in Two-Body Nonleptonic Charmless b-Hadron DecaysNov 25 2004Relative branching fractions of B^0_d,s -> h^+ h^'- decays (where h, h' = K or pi) and the direct CP asymmetry A_CP in the B^0_d -> K^+ pi^- mode are measured with 179 +- 11 pb^-1 of data collected at sqrt{s} = 1.96 TeV using the CDF II detector at the ... More
The Cosmological Angular Momentum Problem of Low-Mass Disk GalaxiesJul 05 2000The rotational properties of the visible and dark components of low-mass disk galaxies (vrot<=100 km/s) are investigated using the Swaters sample. The rotational parameter lambda'=lambda_DM*(j_d/m_d) is determined, where lambda_DM is the dark halo spin ... More
An Induction Principle and Pigeonhole Principles for K-Finite SetsMay 20 1994We establish a course-of-values induction principle for K-finite sets in intuitionistic type theory. Using this principle, we prove a pigeonhole principle conjectured by Benabou and Loiseau. We also comment on some variants of this pigeonhole principle. ... More
The convergence Newton polygon of a $p$-adic differential equation I : Affinoid domains of the Berkovich affine lineAug 29 2012May 29 2014We prove that the radii of convergence of the solutions of a $p$-adic differential equation $\mathcal{F}$ over an affinoid domain $X$ of the Berkovich affine line are continuous functions on $X$ that factorize through the retraction of $X\to\Gamma$ of ... More
Cutoff effects of heavy quark vacuum polarization at one-loop orderMar 09 2012The charm-quark mass is typically not so far from the cutoff 1/a in lattice simulations. Its determinant may then potentially introduce large cutoff effects. We choose the O(a)-improved Wilson formulation and compute the vacuum polarization effects in ... More
The effect of using different EOS in modelling the Alpha Centauri binary systemNov 17 2004In this preliminary study we investigate the effects of using different equations of state (CEFF and OPAL) in the calibration of the binary system Alpha Centauri. Constraints coming from the detection of acoustic oscillations in Alpha Centauri A and B ... More
Star products on graded manifolds and $α'$-corrections to Courant algebroids from string theoryDec 18 2014Mar 31 2015Deformation theory refers to an apparatus in many parts of math and physics for going from an infinitesimal (= first order) deformation to a full deformation, either formal or convergent appropriately. If the algebra being deformed is that of observables, ... More
Tracing the Cluster Internal Dynamics with Member GalaxiesOct 02 2001The analysis of the spatial distribution and kinematics of galaxies in clusters allows one to determine the cluster internal dynamics. In this paper, I review the state of the art of this topic. In particular, I summarize what we have learned so far about ... More
Our Best Friend, The Coma Cluster (A Historical Review)Nov 21 1997In this paper I describe how our knowledge and understanding of the properties and structure of the Coma cluster of galaxies has evolved through the years, since early this century, when the first maps of the density of nebulae in the Coma region were ... More
Extraction-Controlled Quantum Cascade LasersJul 30 2010A simple two-well design for terahertz quantum cascade lasers is proposed which is based on scattering injection and the efficient extraction of electrons from the lower laser level by resonant tunneling. In contrast to existing designs this extraction ... More
Electric-Magnetic Duality and Topological InsulatorsJul 09 2009Oct 03 2009We work out the action of the SL(2,Z) electric-magnetic duality group for an insulator with a non-trivial permittivity, permeability and theta-angle. This theory has recently been proposed to be the correct low-energy effective action for topological ... More