Results for "B. Giaccone"

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Algorithmic clothing: hybrid recommendation, from street-style-to-shopMay 26 2017Nov 12 2017In this paper we detail Cortexica's ( recommendation framework -- particularly, we describe how a hybrid visual recommender system can be created by combining conditional random fields for segmentation and deep neural networks ... More
Errata and comments for "Numerical and analytical modeling of busbar systems"Oct 15 2014This note covers two parts. The first one provides an errata to the paper "Numerical and analytical modeling of busbar systems". We mainly give the correction for three equations affected by a typographical mistake. Despite the corrections that we are ... More
Low RF power plasma ignition and detection for in-situ cleaning of 1.3 GHz 9-cell cavitiesFeb 08 2019Superconducting Radio Frequency (SRF) cavities performance preservation is crucial, from vertical test to accelerator operation. Field Emission (FE) is still one of the performance limiting factors to overcome and plasma cleaning has been proven successful ... More
The Role of Inter-Controller Traffic for Placement of Distributed SDN ControllersMay 30 2016Aug 09 2016We consider a distributed Software Defined Networking (SDN) architecture adopting a cluster of multiple controllers to improve network performance and reliability. Besides the Openflow control traffic exchanged between controllers and switches, we focus ... More
Rotating black holes, global symmetry and first order formalismOct 15 2012In this paper we consider axisymmetric black holes in supergravity and address the general issue of defining a first order description for them. The natural setting where to formulate the problem is the De Donder-Weyl-Hamilton-Jacobi theory associated ... More
Black hole solutions to the $F_4$-model and their orbits (I)Mar 28 2012Dec 30 2014In this paper we continue the program of the classification of nilpotent orbits using the approach developed in arXiv:1107.5986, within the study of black hole solutions in D=4 supergravities. Our goal in this work is to classify static, single center ... More
Analyzing the Performance of LRU Caches under Non-Stationary Traffic PatternsJan 21 2013This work presents, to the best of our knowledge of the literature, the first analytic model to address the performance of an LRU (Least Recently Used) implementing cache under non-stationary traffic conditions, i.e., when the popularity of content evolves ... More
Unravelling the Impact of Temporal and Geographical Locality in Content Caching SystemsJan 14 2015To assess the performance of caching systems, the definition of a proper process describing the content requests generated by users is required. Starting from the analysis of traces of YouTube video requests collected inside operational networks, we identify ... More
Stochastic Optimization of Service Provision with Selfish UsersSep 16 2013We develop a computationally efficient technique to solve a fairly general distributed service provision problem with selfish users and imperfect information. In particular, in a context in which the service capacity of the existing infrastructure can ... More
Content-centric Routing in Wi-Fi Direct Multi-group NetworksDec 02 2014The added value of Device-to-Device (D2D) communication amounts to an efficient content discovery mechanism that enables users to steer their requests toward the node most likely to satisfy them. In this paper, we address the implementation of content-centric ... More
Temporal Locality in Today's Content Caching: Why it Matters and How to Model itMay 30 2013Sep 10 2013The dimensioning of caching systems represents a difficult task in the design of infrastructures for content distribution in the current Internet. This paper addresses the problem of defining a realistic arrival process for the content requests generated ... More
Four-point correlator constraints on electromagnetic chiral parameters and resonance effective LagrangiansMay 21 2004Jun 01 2004We pursue the analysis of a set of generalized DGMLY sum rules for the electromagnetic chiral parameters at order $e^2p^2$ and discuss implications for effective Lagrangians with resonances. We exploit a formalism in which charge spurions are introduced ... More
Electromagnetic corrections in the anomaly sectorMay 21 2002Chiral perturbation theory in the anomaly sector for $N_f=2$ is extended to include dynamical photons, thereby allowing a complete treatment of isospin breaking. A minimal set of independent chiral lagrangian terms is determined and the divergence structure ... More
Breaking and restoring of diffeomorphism symmetry in discrete gravitySep 30 2009We discuss the fate of diffeomorphism symmetry in discrete gravity. Diffeomorphism symmetry is typically broken by the discretization. This has repercussions for the observable content and the canonical formulation of the theory. It might however be possible ... More
Centrality dependence of charged antiparticle to particle ratios near mid-rapidity in d+Au collisions at sqrt(s_NN)=200 GeVSep 17 2003The ratios of the yields of charged antiparticles to particles have been obtained for pions, kaons, and protons near mid-rapidity for d+Au collisions at sqrt(s_NN) = 200 GeV as a function of centrality. The reported values represent the ratio of the yields ... More
Centrality dependence of charged hadron transverse momentum spectra in d+Au collisions at sqrt(s_NN) = 200 GeVJun 18 2003We have measured transverse momentum distributions of charged hadrons produced in d+Au collisions at sqrt(s_NN) = 200 GeV. The spectra were obtained for transverse momenta 0.25 < p_T < 6.0 GeV/c, in a pseudorapidity range of 0.2 < eta < 1.4 in the deuteron ... More
Scaling Variable for Nuclear Shadowing in Deep-Inelastic ScatteringSep 22 1995A new scaling variable is introduced in terms of which nuclear shadowing in deep-inelastic scattering is universal, i.e. independent of $A$, $Q^2$ and $x$. This variable can be interpreted as a measure of the number of gluons probed by the hadronic fluctuations ... More
Type I background fields in terms of type IIB onesApr 16 2008We choose such boundary conditions for open IIB superstring theory which preserve N=1 SUSY. The explicite solution of the boundary conditions yields effective theory which is symmetric under world-sheet parity transformation $\Omega:\sigma\to-\sigma$. ... More
Gauge symmetries decrease the number of Dp-brane dimensionsApr 19 2006Aug 09 2006It is known that the presence of antisymmetric background field $B_{\mu\nu}$ leads to noncommutativity of Dp-brane manifold. Addition of the linear dilaton field in the form $\Phi(x)=\Phi_0+a_\mu x^\mu$, causes the appearance of the commutative Dp-brane ... More
Continuum Lowering -- A New PerspectiveSep 05 2013Apr 23 2014What is meant by continuum lowering and ionization potential depression (IPD) in a Coulomb system depends upon precisely what question is being asked. It is shown that equilibrium (equation-of-state) phenomena and non-equilibrium dynamical processes like ... More
Gauge symmetries decrease the number of Dp-brane dimensions. II. Inclusion of the Liouville termNov 17 2006Apr 26 2007The presence of the antisymmetric background field $B_{\mu\nu}$ leads to the noncommutativity of the Dp-brane manifold, while the linear dilaton field in the form $\Phi(x)=\Phi_0+a_\mu x^\mu$, causes the appearance of the commutative Dp-brane coordinate, ... More
A Riemannian approach to low-rank algebraic Riccati equationsDec 17 2013May 28 2014We propose a Riemannian optimization approach for computing low-rank solutions of the algebraic Riccati equation. The scheme alternates between fixed-rank optimization and rank-one updates. The fixed-rank optimization is on the set of fixed-rank symmetric ... More
Inclusive Charmed-Baryon Decays and LifetimesApr 30 1997Jul 11 1997We have quantitatively reanalyzed the inclusive charmed-baryon decays. New ingredients are the Voloshin preasymptotic effects in semileptonic decays and the Cabibbo-subleading contributions to both semileptonic and nonleptonic decays. It has been found ... More
Power spectrum of electron number density perturbations at cosmological recombination epochDec 12 2008Feb 19 2009The power spectrum of number density perturbations of free electrons is obtained for the epoch of cosmological recombination of hydrogen. It is shown that amplitude of the electron perturbations power spectrum of scales larger than acoustic horizon exceeds ... More
Energy dependence of particle multiplicities in central Au+Au collisionsAug 08 2001We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at sqrt(s_NN) = 200GeV. For the 6% most central collisions, we obtain dN_ch/deta|_|eta|<1 = 650 +/- 35 (syst). Compared to collisions at sqrt(s_NN) ... More
Transverse Momentum and Rapidity Dependence of HBT Correlations in Au+Au Collisions at sqrt(s_NN) = 62.4 and 200 GeVSep 01 2004Two-particle correlations of identical charged pion pairs from Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV were measured by the PHOBOS experiment at RHIC. Data for the 15% most central events were analyzed with Bertsch-Pratt and Yano-Koonin-Podgoretskii ... More
Dirichlet boundary conditions in type IIB superstring theory and fermionic T-dualityFeb 01 2012Jul 02 2012In this article we investigate the relation between consequences of Dirichlet boundary conditions (momenta noncommutativity and parameters of the effective theory) and background fields of fermionic T-dual theory. We impose Dirichlet boundary conditions ... More
Noncommutativity relations in type IIB theory and their supersymmetryMay 07 2010In the present paper we investigate noncommutativity of $D9$ and $D5$-brane world-volumes embedded in space-time of type IIB superstring theory. Boundary conditions, which preserve half of the initial supersymmetry, are treated as canonical constraints. ... More
Noncommutativity in space-time extended by Liouville fieldNov 28 2007Oct 09 2009The world-sheet quantum conformal invariance can be realized in the presence of the conformal factor $F$, by inclusion of Liouville term. In the background with linear dilaton field, $\Phi(x)=\Phi_0+a_\mu x^\mu$, the field $F$ becomes a new noncommutative ... More
The Magnus property for direct productsMay 05 2016Jun 14 2016A group G is said to have the Magnus property if the following holds: whenever two elements x,y have the same normal closure, then x is conjugate to y or its inverse. We prove: Let p be an odd prime, and let G,H be residually finite-p groups with the ... More
Certain Topics on the Lie Algebra gl(lambda) Representation TheoryMar 15 1997The Lie algebra gl(lambda) dependent on the complex parameter lambda is a continuous version of the Lie algebra gl(inf) of infinite matrices with only finite number of nonzero entries. The gl(lambda) was first introduced by B.L.Feigin in [1] in connection ... More
Consequences of energy conservation in relativistic heavy-ion collisionsAug 15 2005Complete characterization of particle production and emission in relativistic heavy-ion collisions is in general not feasible experimentally. This work demonstrates, however, that the availability of essentially complete pseudorapidity distributions for ... More
Studies of multiplicity in relativistic heavy-ion collisionsNov 08 2004Nov 29 2004In this talk I'll review the present status of charged particle multiplicity measurements from heavy-ion collisions. The characteristic features of multiplicity distributions obtained in Au+Au collisions will be discussed in terms of collision centrality ... More
Pseudorapidity Distribution of Charged Particles in d + Au Collisions at $\sqrt{s_{_{NN}}$ = 200 GeVNov 10 2003The measured pseudorapidity distribution of primary charged particles in minimum-bias d + Au collisions at ${\sqrt{s_{_{NN}}} = \rm {200 GeV}}$ is presented for the first time. This distribution falls off less rapidly in the gold direction as compared ... More
The Radioactive Beam Program at ArgonneJun 06 2006In this talk I will present selected topics of the ongoing radioactive beam program at Argonne and discuss the capabilities of the CARIBU radioactive ion production facility as well as plans for construction of a novel superconducting solenoid spectrometer. ... More
Ratios of charged antiparticles to particles near mid-rapidity in Au+Au collisions at sqrt(s_NN) = 130 GeVApr 18 2001We have measured the ratios of antiparticles to particles for charged pions, kaons and protons near mid-rapidity in central Au+Au collisions at sqrt(s_NN) = 130 GeV. For protons, we observe pbar/p = 0.60 +/- 0.04 (stat.) +/- 0.06 (syst.) in the transverse ... More
Towards a strong-coupling theory of QCD at finite densitySep 02 2002We apply strong-coupling perturbation theory to the QCD lattice Hamiltonian. We begin with naive, nearest-neighbor fermions and subsequently break the doubling symmetry with next-nearest-neighbor terms. The effective Hamiltonian is that of an antiferromagnet ... More
Blandford's Argument: The Strongest Continuous Gravitational Wave SignalApr 18 2008Aug 18 2008For a uniform population of neutron stars whose spin-down is dominated by the emission of gravitational radiation, an old argument of Blandford states that the expected gravitational-wave amplitude of the nearest source is independent of the deformation ... More
Time Evolution of the Spread of Diseases with a General Infectivity Profile on a Complex Dynamic NetworkMay 21 2010This manuscript introduces a new analytical approach for studying the time evolution of disease spread on a finite size network. Our methodology can accommodate any disease with a general infectivity profile. This new approach is able to incorporate the ... More
Geometrically thin accretion disk around Maclaurin spheroidNov 22 2014We investigated a semi-analytic and numerical model to study the geometrically thin and optically thick accretion disk around Maclaurin spheroid (MS). The main interest is in the inner region of the so called {\alpha}-disk, {\alpha} being the viscosity ... More
A Search for Gamma-Ray Bursts and Pulsars, and the Application of Kalman Filters to Gamma-Ray ReconstructionFeb 04 2002Part I describes the analysis of periodic and transient signals in EGRET data. A method to search for the transient flux from gamma-ray bursts independent of triggers from other gamma-ray instruments is developed. Several known gamma-ray bursts were independently ... More
Open strings in relativistic ion trapsFeb 20 2003Apr 04 2003Electromagnetic plane waves provide examples of time-dependent open string backgrounds free of $\alpha'$ corrections. The solvable case of open strings in a quadrupolar wave front, analogous to pp-waves for closed strings, is discussed. In light-cone ... More
Charged Particle Multiplicities in Ultra-relativistic Au+Au and Cu+Cu CollisionsApr 26 2006The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ... More
The significance of the fragmentation region in ultrarelativistic heavy ion collisionsOct 09 2002We present measurements of the pseudorapidity distribution of primary charged particles produced in Au+Au collisions at three energies, sqrt(s_{NN}) = 19.6, 130, and 200 GeV, for a range of collision centralities. The centrality dependence is shown to ... More
Uniform semiclassical expansions for the direct part of Franck-Condon transitionsOct 13 1997Semiclassical expansions for traces involving Greens functions have two contributions, one from the periodic or recurrent orbits of the classical system and one from the phase space volume, i.e. the paths of infinitesimal length. Quantitative calculations ... More
RF depolarizing resonances in the presence of a full Siberian snake and full snake spin-flippingApr 18 2003Frequent polarization reversals, or spin-flips, of a stored polarized beam in a high energy scattering asymmetry experiments may greatly reduce systematic errors of spin asymmetry measurements. A spin-flipping technique is being developed by using rf ... More
Lower estimates of transition densities and bounds on exponential ergodicity for stochastic PDE'sFeb 18 2004Sep 25 2006A formula for the transition density of a Markov process defined by an infinite-dimensional stochastic equation is given in terms of the Ornstein--Uhlenbeck bridge and a useful lower estimate on the density is provided. As a consequence, uniform exponential ... More
Generalized Dynamic Scaling for Critical Magnetic SystemsMay 22 1997The short-time behaviour of the critical dynamics for magnetic systems is investigated with Monte Carlo methods. Without losing the generality, we consider the relaxation process for the two dimensional Ising and Potts model starting from an initial state ... More
Deterministic Equations of Motion and Phase Ordering DynamicsSep 22 1999We numerically solve microscopic deterministic equations of motion for the 2D $\phi^4$ theory with random initial states. Phase ordering dynamics is investigated. Dynamic scaling is found and it is dominated by a fixed point corresponding to the minimum ... More
On the quantum theory of pure gravitationAug 19 2002A quantum theory of the region of pure gravitation was given earlier in two papers [gr-qc/9908036 (Phys. Lett. A {\bf {265}}, 1 (2000)); gr-qc/0101056]. In this paper I provide further insight into the physics of this region.
Soft asymptotics with mass gapAug 30 2013Dec 05 2013From the operator product expansion the gluon condensate controls a certain power law correction to the ultraviolet behavior of the gauge theory. This is reflected by the asymptotic behavior of the effective gluon mass function as determined by its Schwinger-Dyson ... More
Far from standard Higgs couplingsJun 06 2013In this short note we consider a permitted region in the space of couplings of the 126 GeV boson that extends far away from the standard model Higgs couplings. This region is of interest for more natural models of electroweak symmetry breaking. Stronger ... More
Dynamical symmetry breaking, CP violation, and a Higgs-like particleJan 02 2013Apr 08 2013A pseudoscalar associated with dynamical symmetry breaking can mix with a heavier scalar when CP is violated. We study how such a mixed state that is mostly pseudoscalar can resemble the observed 125 GeV particle. The production rate from $gg$ is enhanced ... More
A pseudoscalar at the LHC: technicolor vs a fourth familyDec 30 2011Mar 06 2012Condensates of colored fermions driving electroweak symmetry breaking could give rise to a light pseudoscalar that would show up in the Higgs search at the LHC. The branching ratios of its decay will distinguish it from the Higgs and illuminate its origin. ... More
Mass gap without vacuum energyJul 01 2009We consider soft nonlocal deformations of massless theories that introduce a mass gap. By use of a renormalization scheme that preserves the ultraviolet softness of the deformation, renormalized quantities of low mass dimension, such as normal mass terms, ... More
The heavy quark search at the LHCMay 14 2007We explore further the discovery potential for heavy quarks at the LHC, with emphasis on the $t'$ and $b'$ of a sequential fourth family associated with electroweak symmetry breaking. We consider QCD multijets, $t\bar{t}+\rm{jets}$, $W+\rm{jets}$ and ... More
t' at the LHC: the physics of discoveryFeb 05 2007Mar 15 2007A search for a fourth family at the LHC is presently a low priority, but we argue that an effective search can be conducted early with only a few inverse femtobarns of data. We discuss a method based on invariant masses of single jets for identifying ... More
From turbulence to financial time seriesSep 11 1997Feb 26 1998We develop a framework especially suited to the autocorrelation properties observed in financial times series, by borrowing from the physical picture of turbulence. The success of our approach as applied to high frequency foreign exchange data is demonstrated ... More
CP Violation from the Neutrino Sector: A Case for the Superweak ModelMay 05 1997Oct 16 1997We discuss how CP violation originating in the right-handed neutrino sector can feed into the quark sector, in an otherwise CP invariant theory. The dominant effects are superweak, and we suggest that this may yield a natural resolution of the strong ... More
Baryon axial currentsNov 19 1998The baryon axial currents are calculated at one-loop order in heavy baryon chiral perturbation theory by employing both a cutoff and dimensional regularization. Data from the semileptonic baryon decays is used to perform a least-squares fit to the two ... More
Photoproduction of eta and eta-prime mesons off nucleons close to thresholdFeb 09 2001The importance of Born terms and resonance exchange for eta and eta-prime photoproduction off both the proton and neutron within U(3) baryon chiral perturbation theory is investigated. Low-lying resonances such as the vector mesons and J^P= 1/2^+, 1/2^- ... More
Proper local complete intersection morphisms preserve perfect complexesOct 10 2012Oct 13 2012Let $f : X \longrightarrow Y$ be a proper and local complete intersection morphism of schemes. We prove that $\mathbb{R}f_{*}$ preserves perfect complexes, without any projectivity or noetherian assumptions. This provides a different proof of a theorem ... More
Flat descent for Artin n-stacksNov 18 2009Jan 07 2010We prove two flat descent statements for Artin n-stacks. We first show that an n-stack for the etale topology which is an Artin n-stack in the sense of HAGII, is also an n-stack for the fppf topology. Moreover, an n-stack for the fppf topology which possess ... More
Operations on derived moduli spaces of branesJul 01 2013Oct 23 2013The main theme of this work is the study of the operations that naturally exist on moduli spaces of maps $Map(S,X)$, also called the space of branes of $X$ with respect $S$. These operations will be constructed as operations on the (quasi-coherent) derived ... More
Numerical simulations on the 4d Heisenberg spin glassOct 17 1994Oct 18 1994We study the 4d Heisenberg spin glass model with Gaussian nearest-neighbor interactions. We use finite size scaling to analyze the data. We find a behavior consistent with a finite temperature spin glass transition. Our estimates for the critical exponents ... More
The Klein-Gordon Equation of a Rotating Charged Hairy Black Hole in (2+1) DimensionsJun 22 2015Nov 22 2015In this paper, we consider the Klein-Gordon equation in a 3D charged rotating hairy black hole background to study behavior of a massive scalar field. In the general case we find periodic-like behavior for the scalar field which may be vanishes at the ... More
Extended Chaplygin Gas in Horava-Lifshitz GravityDec 08 2014Jun 25 2016In this paper, we investigate cosmological models of the extended Chaplygin gas in a universe governed by Horava-Lifshitz gravity. The equation of state for an extended Chaplygin gas is a $(n+2)$-variable equation determined by $A_{n}$, $\alpha$, and ... More
Excitation of oscillation modes by tides in close binaries: constraints on stellar and orbital parametersSep 01 2003The parameter space favourable for the resonant excitation of free oscillation modes by dynamic tides in close binary components is explored using qualitative considerations to estimate the order of magnitude of the tidal force and the frequency range ... More
Polarized deep inelastic scattering at low Bjorken x and resummation of logarithmic corrections, $ln^2(1/x)$Apr 29 2003For an accurate description of the polarized deep inelastic scattering at low $x$ including the logarithmic corrections, $\ln^2(1/x)$, is required. These corrections resummed strongly influence the behaviour of the spin structure functions and their moments. ... More
Recovering corrections in the analysis of intermittent dataMar 22 1999Apr 13 1999The analysis of intermittent data is improved. The standard method of recovering the history of a particle cascade is proved in general not to reproduce the structure of the true cascade. The recovering corrections to the standard method are proposed ... More
Inclusive single particle density in configuration space from the QCD-cascade in DLA approximationMay 30 1997The structure of the QCD gluonic cascade in configuration space is investigated. The explicit form of the inclusive single particle density in configuration space transverse coordinates is derived in the double logarithmic approximation (DLA) of QCD. ... More
Operational Concepts of Large TelescopesAug 22 1996The singular way of scheduling at major observatories has favored certain types of astronomy. This has led to the discrimination of certain types of observations which could not be accommodated. It is the goal of future operations to open possibilities ... More
A note on the Georgi vector limit at finite temperature/densitySep 13 2001Sep 17 2001The mechanism of chiral symmetry restoration in the context of the Georgi Vector Limit (GVL) at finite temperature/density is discussed. It is suggested that, whereas the system may be driven to the GVL, the fact of reaching the point of restoration does ... More
Chiral properties of hadron correlators in nuclear matterApr 14 2000The constraints imposed by chiral symmetry on hadron correlation functions in nuclear medium are discussed. It is shown that these constraints imply a certain structure for the in-medium hadron correlators and lead to the cancelation of the order $\rho ... More
Toward Chiral Theory of NN interactions in nuclear matterFeb 07 2000The effective chiral theory of the in-medium NN interactions is considered. The shallow bound states, which complicate the effective field theory analysis in vacuum do not exist in matter. We show that the next-to-leading order terms in the chiral expansion ... More
Using color photometry to separate transiting exoplanets from false positivesJun 08 2004Jul 14 2004The radial velocity technique is currently used to classify transiting objects. While capable of identifying grazing binary eclipses, this technique cannot reliably identify blends, a chance overlap of a faint background eclipsing binary with an ordinary ... More
Improvements to Existing Transit Detection Algorithms and Their ComparisonJul 28 2003In Tingley (2003), all available transit detection algorithms were compared in a simple, rigorous test. However, the implementation of the Box-fitting Least Squares (BLS) approach of Kovacs et al. (2002) used in that paper was not ideal for those purposes. ... More
A Method for stability analysis of magnetic bearings : Basic stability criteriaJul 11 2016In this work I outline a general procedure for dynamic modeling and stability analysis of a magnetic bearing, which is a rotating shaft confined inside a chamber through electromagnetic forces alone. I consider the simplest type of self-propelled bearing, ... More
The Light of ExistenceNov 26 2010Jul 13 2012This chapter derives the properties of light from the properties of processing, including its ability to be both a wave and a particle, to respond to objects it doesn't physically touch, to take all paths to a destination, to choose a route after it arrives, ... More
The emergence of the physical world from information processingAug 15 2010This paper links the conjecture that the physical world is a virtual reality to the findings of modern physics. What is usually the subject of science fiction is here proposed as a scientific theory open to empirical evaluation. We know from physics how ... More
Learning Term Weights for Ad-hoc RetrievalJun 14 2016Most Information Retrieval models compute the relevance score of a document for a given query by summing term weights specific to a document or a query. Heuristic approaches, like TF-IDF, or probabilistic models, like BM25, are used to specify how a term ... More
Computation of the High Temperature Coulomb Density Matrix in Periodic Boundary ConditionsApr 27 2009The high temperature many-body density matrix is fundamental to path integral computation. The pair approximation, where the interaction part is written as a product of pair density matrices, is commonly used and is accurate to order tau squared, where ... More
Effective Lagrangians in $2 + ε$ DimensionsJul 13 1998Jun 09 1999The failure of the the loop expansion and effective lagrangians in two dimensions, which traditionally hinges on a power counting argument is considered. We establish that the book keeping device for the loop expansion, a role played by (the reciprocal ... More
The Low Energy Expansion for Pion-Pion Scattering and Crossing Symmetry in Dispersion RelationsFeb 17 1998We show that a suitable setting for comparison of the low-energy representation for pion-pion scattering amplitudes, with dispersive representation for these amplitudes, is provided by certain manifestly crossing symmetric dispersion relations. We begin ... More
Chiral Perturbation Theory for Nuclear PhysicistsDec 26 1997Chiral perturbation theory is the low energy effective theory of the strong interactions for the light pseudoscalar degrees of freedom. This program is based on effective Lagrangian techniques and is an expansion in the powers of the momenta and the powers ... More
Fundamental particles and their interactionsAug 03 2005In this article the current understanding of fundamental particles and their interactions is presented for the interested non-specialist, by adopting a semi-historical path. A discussion on the unresolved problems is also presented.
On a sidereal time variation of the Lorentz forceSep 09 2015We consider a search for a sidereal time variation of the beam trajectory in the cyclotron motion in a static magnetic field. The combination of two beams moving in opposite directions could allow a test of the radius stability with sensitivity approaching ... More
Nuclear mass form factors from coherent photoproduction of $π^0$ mesonsSep 01 2005Data for coherent photoproduction of $\pi^0$ mesons from nuclei ($^{12}$C, $^{40}$Ca, $^{93}$Nb, $^{nat}$Pb), recently measured with the TAPS detector at the Mainz MAMI accelerator, have been analyzed in view of the mass form factors of the nuclei. The ... More
Variability of young stellar objects: accretion, disks, outflows and magnetic activityApr 24 2015This article represents a short review of the variability characteristics of young stellar objects. Variability is a key property of young stars. Two major origins may be distinguished: a scaled-up version of the magnetic activity seen on main-sequence ... More
In-medium properties of nucleon resonancesDec 06 2004Recent experimental results for the in-medium properties of nucleon resonances are discussed. The experiments were done with the TAPS detector at the tagged photon beam of the MAMI accelerator in Mainz. Measured was the photoproduction of mesons (final ... More
Photoproduction of mesons from nuclei - In-medium properties of hadronsNov 18 2004Recent experimental results for the in-medium properties of hadrons obtained with photoproduction of mesons from nuclei are discussed. The experiments were done with the TAPS detector at the tagged photon beam of the MAMI accelerator in Mainz. Measured ... More
Beauty and charm results from $B$-factoriesJan 11 2009Mar 22 2009We present the proceedings of the lectures given at the 2008 Helmholtz International Summer School Heavy Quark Physics at the Bogoliubov Laboratory of Theoretical Physics in Dubna. In two lectures we present recent results from the existing $B$-factories ... More
Virtual quarks, vacuum stability and scalar meson physicsNov 26 2001Results are reviewed, which provide relations between the response (and eventual instability) of the chiral QCD vacuum to an increase of the number of massless quarks in the theory and the observed violations of the large $N_c$ expansion in the scalar ... More
Chiral Sum-Rules for ${\cal L}^{WZ}_{(6)}$ Parameters and Application to $π^0,η,η'$ DecaysJul 29 1994Mar 23 1995The chiral expansion of the low energy processes $\pi^0\to\gamma\gamma$ and $\eta\to\gamma\gamma$ is reconsidered with particular emphasis on the question of the evaluation of the two low-energy parameters from ${\cal L}^{WZ}_{(6)}$ which are involved ... More
N_f Dependence of the Quark Condensate from a Chiral Sum RuleSep 08 1999Oct 28 1999How fast does the quark condensate in QCD-like theories vary as a function of $N_f$ is inferred from real QCD using chiral perturbation theory at order one-loop. A sum rule is derived for the single relevant chiral coupling-constant, $L_6$. A model independent ... More
Mass and Angular Momentum of Sgr A*Oct 13 2004For very fast spinning black holes with a>0.9953 the orbital velocity of a test particle unexpectly shows a positive radial gradient for low orbits, an effect of GR which has been overlooked so far. For a=0.99616 the maximum radial change of the orbital ... More
Maps for analysis of nonlinear dynamicsSep 23 1998Area preserving maps provide the simplest and most accurate means to visualize and quantify the behavior of nonlinear systems. Convenience of the mapping equations of motion for investigation of transition to chaotic behavior in dynamics of classical ... More
Anomalous dimuon charge asymmetry in proton-antiproton collisionsMay 08 2014We present an overview of the measurements of the like-sign dimuon charge asymmetry by the DO Collaboration at the Fermilab Tevatron proton-antiproton Collider. The results differ from the Standard Model prediction of CP violation in mixing and interference ... More
On CP violation and the measurement of the dimuon charge asymmetry at hadron collidersJul 26 2006B factories measure the CP violation parameter of B^0 Bbar^0 mixing and decay. Hadron colliders measure the dimuon charge asymmetry of an admixture of B hadrons. In this note we discuss a subtle point on how the CP violation parameter of B^0_s Bbar^0_s ... More
What future does the universe have?Oct 23 2002We discuss the future evolution of the universe in the light of recent observations. The apparent luminosity vs. redshift of supernovae favor an accelerating universe. However an Einstein-de Sitter critical universe should not be ruled out yet.