Results for "B. Giaccone"

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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
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
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
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
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
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
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
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
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.
Intriguing Trends in Nuclear Physics Articles AuthorshipNov 07 2014Nov 24 2014The increase in authorship of nuclear physics publications has been investigated using the large statistical samples. This has been accomplished with nuclear data mining of nuclear science references (NSR) and experimental nuclear reaction (EXFOR) databases. ... More
Collisional relaxation of two-dimensional self-gravitating systemsDec 05 2012May 25 2013Systems with long range interactions present generically the formation of quasi-stationary long-lived non-equilibrium states. These states relax to Boltzmann equilibrium following a dynamics which is not well understood. In this paper we study this process ... More
Hadron Spectroscopy in electrons-protons Collisions at HERAFeb 01 2006Recent results from H1 and ZEUS on searches for exotic baryons in $ep$ collisions at HERA are reviewed. Evidence for the production of the strange pentaquark $\Theta^+$ and of a narrow anti-charmed baryon decaying to $D^{*-} p$ together with negative ... More
Geometric aspects of the Maximum Principle and lifts over a bundle mapDec 04 2002A coordinate-free proof of the Maximum Principle is provided in the specific case of an optimal control problem with fixed time. Our treatment heavily relies on a special notion of variation of curves that consist of a concatenation of integral curves ... More
Phase separation in the two-dimensional electron liquid in MOSFETsMay 07 2002Jan 20 2003We show that the existence of an intermediate phase between the Fermi liquid and the Wigner crystal phases is a generic property of the two-dimensional pure electron liqd in MOSFET's at zero temperature. The physical reason for the existence of these ... More
Elliptic associatorsMar 04 2010Jul 26 2012We construct a genus one analogue of the theory of associators and the Grothendieck-Teichmueller group. The analogue of the Galois action on the profinite braid groups is an action of the arithmetic fundamental group of a moduli space of elliptic curves ... More
Quasi-reflection algebras and cyclotomic associatorsAug 03 2004Oct 17 2007We develop a cyclotomic analogue of the theory of associators. Using a trigonometric version of the universal KZ equations, we prove the formality of a morphism B_n^1 -> (ZZ/N ZZ)^n rtimes S_n, where B_n^1 is a braid group of type B. The formality isomorphism ... More
On some universal algebras associated to the category of Lie bialgebrasJan 08 2001Jan 28 2001In our previous work (math/0008128), we studied the set Quant(K) of all universal quantization functors of Lie bialgebras over a field K of characteristic zero, compatible with duals and doubles. We showed that Quant(K) is canonically isomorphic to a ... More
PBW and duality theorems for quantum groups and quantum current algebrasApr 21 1999Jul 12 1999We give proofs of the PBW and duality theorems for the quantum Kac-Moody algebras and quantum current algebras, relying on Lie bialgebra duality. We also show that the classical limit of the quantum current algebras associated with an untwisted affine ... More
Local unitary equivalence and entanglement of multipartite pure statesMay 28 2010The necessary and sufficient conditions for the equivalence of arbitrary n-qubit pure quantum states under Local Unitary (LU) operations derived in [B. Kraus Phys. Rev. Lett. 104, 020504 (2010)] are used to determine the different LU-equivalence classes ... More
Meson-nucleon scattering and vector mesons in nuclear matterAug 27 1998The properties of vector mesons in nuclear matter are discussed. I examine the constraints imposed by elementary processes on the widths of $\rho$ and $\omega$ mesons in nuclear matter. Furthermore, results for the $\rho$- and $\omega$-nucleon scattering ... More
Invariants of spectral curves and intersection theory of moduli spaces of complex curvesOct 13 2011To any spectral curve S, we associate a topological class {\Lambda}(S) in a moduli space M^b_{g,n} of "b-colored" stable Riemann surfaces of given topology (genus g, n boundaries), whose integral coincides with the topological recursion invariants W_{g,n}(S) ... More
Eigenvalue distribution of large random matrices, from one matrix to several coupled matricesJul 01 1997It has been observed that the statistical distribution of the eigenvalues of random matrices possesses universal properties, independent of the probability law of the stochastic matrix. In this article we find the correlation functions of this distribution ... More
Another algebraic variational principle for the spectral curve of matrix modelsJul 31 2014We propose an alternative variational principle whose critical point is the algebraic plane curve associated to a matrix model (the spectral curve, i.e. the large $N$ limit of the resolvent). More generally, we consider a variational principle that is ... More
The Online Calibration, Operation, and Performance of the CMS Pixel DetectorJan 10 2011The CMS pixel detector consists of approximately 66 million silicon pixels whose analog signals are read out by 15,840 programmable Readout Chips. With the recent startup of the LHC, the detector is now collecting data used for precise vertexing and track-finding. ... More
Associated production of A^0 and Z^0 bosons and Rare Pseudoscalar Higgs DecaysFeb 21 2005Feb 22 2005We study the production of a pseudoscalar Higgs boson A^0 in association with a Z^0 boson at a future international linear collider (ILC). We consider the contributions to this process at the one loop level in the Minimal Supersymmetric Standard Model ... More
What are the galaxies contributing to the Cosmic Infrared Background ?Dec 29 1997Recent optical observations have led to a significant progress in our understanding of galaxy formation and evolution. However, our view on the deep universe is currently limited to the starlight which directly escapes from high-redshift galaxies, since ... More
Relation between concurrence and Berry phase of an entangled state of two spin 1/2 particlesFeb 10 2006We have studied here the influence of the Berry phase generated due to a cyclic evolution of an entangled state of two spin 1/2 particles. It is shown that the measure of formation of entanglement is related to the cyclic geometric phase of the individual ... More
Luscher's mu-term and finite volume bootstrap principle for scattering states and form factorsMar 31 2008We study the leading order finite size correction (Luscher's mu-term) associated to moving one-particle states, arbitrary scattering states and finite volume form factors in 1+1 dimensional integrable models. Our method is based on the idea that the mu-term ... More
Nucleosynthesis in Advective Accretion Disks Around Galactic and Extra-Galactic Black HolesJul 10 1998We compute the nucleosynthesis of materials inside advective disks around black holes. We show that composition of incoming matter can change significantly depending on the accretion rate and accretion disks. These works are improvements on the earlier ... More
On the precise connection between the GRW master-equation and master-equations for the description of decoherenceJan 29 2007We point out that the celebrated GRW master-equation is invariant under translations, reflecting the homogeneity of space, thus providing a particular realization of a general class of translation-covariant Markovian master-equations. Such master-equations ... More
Dephasing in an atomApr 10 2011When an atom in vacuum is near a surface of a dielectric the energy of a fluctuating electromagnetic field depends on a distance between them resulting, as known, in the force called van der Waals one. Besides this fluctuation phenomenon there is one ... More
Underbarrier interferenceMar 29 2009Nov 03 2009Quantum tunneling through a two-dimensional static barrier becomes unusual when a momentum of an electron has a tangent component with respect to a border of the prebarrier region. If the barrier is not homogeneous in the direction perpendicular to tunneling ... More
Tunneling in a magnetic fieldNov 07 2005Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. An oscillatory structure ... More
Loop Variables and Gauge Invariant Exact Renormalization Group Equations for (Open) String Theory -IISep 07 2012Nov 28 2012In arXiv:1202.4298 gauge invariant interacting equations were writ- ten down for the spin 2 and spin 3 massive modes using the exact renor- malization group of a world sheet theory. This is generalized to all the higher levels in this paper. An interacting ... More
Holomorphic Factorization and Renormalization Group in Closed String TheoryApr 27 2004The prescription of Kawai, Lewellen and Tye for writing the closed string tree amplitudes as sums of products of open string tree amplitudes, is applied to the world sheet renormalization group equation. The main point is that regularization of the Minkowski ... More
Loop Variables with Chan-Paton FactorsOct 14 2003Oct 27 2003The Loop Variable method that has been developed for the U(1) bosonic open string is generalized to include non-Abelian gauge invariance by incorporating "Chan-Paton" gauge group indices. The scale transformation symmetry $k(s) \to k(s) \lambda (s)$ that ... More
The Proper Time Equation and the Zamolodchikov MetricSep 16 1995Nov 30 1995The connection between the proper time equation and the Zamolodchikov metric is discussed. The connection is two-fold: First, as already known, the proper time equation is the product of the Zamolodchikov metric and the renormalization group beta function. ... More
Background Independence, Gauge Invariance and Equations of Motion for Closed String ModesDec 05 2014Dec 08 2014In an earlier paper [arXiv:1408.0484] gauge invariant and background covariant equations for closed string modes were obtained from the exact renormalization group equation of the world sheet theory. The background metric (but not the physical metric) ... More
Loop Variables and Gauge Invariant Exact Renormalization Group Equations for Closed String TheoryJun 28 2013Aug 05 2013We formulate the Exact Renormalization Group on the string world sheet for closed string backgrounds. The same techniques that were used for open strings is used here. There are some subtleties. One is that holomorphic factorization of the closed string ... More
Loop Variables and the (Free) Open String in a Curved BackgroundDec 03 2004Dec 13 2004Using the loop variable formalism as applied to a sigma model in curved target space, we give a systematic method for writing down gauge and generally covariant equations of motion for the modes of the free open string in curved space. The equations are ... More
Leptoproduction of Polarized Vector MesonsOct 19 2001We present a status report on a study of vector meson leptoproduction for the HERA energy range on the basis of the generalized handbag approach. In contrast to the leading twist approach transverse degrees of freedom as well as Sudakov suppressions are ... More
Boxing with KonishiDec 20 2007The spin chain formulation of the operator spectrum of the N=4 super Yang-Mills theory is haunted by the problem of ``wrapping'', i.e. the inapplicability of the formalism for short spin chain length at high loop-order. The first instance of wrapping ... More
A Modification of the Social Force Model by ForesightDec 03 2009The motion of pedestrian crowds (e.g. for simulation of an evacuation situation) can be modeled as a multi-body system of self driven particles with repulsive interaction. We use a few simple situations to determine the simplest allowed functional form ... More
Klein-Gordon Equation for Quark Pairs in Color SuperconductorJul 26 2004Sep 23 2004The wave equation is derived for quark pairs in color superconductor in the regime of low density / strong coupling.
Existence of fixed points for a particular multifunctionJan 25 2010We prove a fixed point theorem for a particular multifunction from the unit sphere of a reflexive Banach space with the Kadec-Klee property into itself.
Low-x PhysicsAug 28 2000Low-x physics is reviewed, with particular emphasis on searches for deviations from GLAP evolution of the parton densities. Although there are several intriguing indications, both in HERA and Tevatron data, as yet there is no unambiguous evidence for ... More
Modular Localization and the Bootstrap-Formfactor ProgramFeb 19 1997We extend the ''modular localization'' principle from free to interacting theories and test its power for the special class of d=1+1 factorizing models.
QCD Corrections to Spin Dependent Drell-Yan and a Global Subtraction SchemeNov 02 1995We present QCD corrections to the Drell-Yan process in the transversely polarized, longitudinally polarized and unpolarized cases. The analytical results are presented in a form valid for all $n$-dimensional regularization schemes. A universal mass factorization ... More
KAM for KG on $\mathbb S^2$ and for the quantum harmonic oscillator on $\mathbb R^2$Oct 29 2014In this paper we prove an abstract KAM theorem adapted to the Klein Gordon equation on the sphere $\mathbb S^2$ and for the quantum harmonic oscillator on $\mathbb R^2$ with regularizing nonlinearity.
More on quantum groups from the the quantization point of viewJan 22 1993Star products on the classical double group of a simple Lie group and on corresponding symplectic grupoids are given so that the quantum double and the "quantized tangent bundle" are obtained in the deformation description. "Complex" quantum groups and ... More
Tangent and normal bundles in almost complex geometryApr 14 2003Jun 10 2005In this paper we define and study pseudoholomorphic vector bundles structures, particular cases of which are tangent and normal bundle almost complex structures. These are intrinsically related to the Gromov D-operator. As an application we deduce normal ... More
General Solution of the WZNW System and 2D Induced Gravity in Curved Space-timeSep 21 1998We find the general solution of the equations of motion for the WZNW system in curved space-time for arbitrary external gauge fields. Using the connection between the WZNW system for $SL(2,R)$ group and 2D induced gravity we obtain the general solution ... More
Geometric gauge potentials and forces in low-dimensional scattering systemsFeb 14 2012Oct 23 2012We introduce and analyze several low-dimensional scattering systems that exhibit geometric phase phenomena. The systems are fully solvable and we compare exact solutions of them with those obtained in a Born-Oppenheimer projection approximation. We illustrate ... More
Density waves in the shearing sheet III. Disc heatingApr 25 2001The problem of dynamical heating of galactic discs by spiral density waves is discussed using the shearing sheet model. The secular evolution of the disc is described quantitatively by a diffusion equation for the distribution function of stars in the ... More
Dim Matter in the Disks of Low Surface Brightness GalaxiesApr 23 2002An attempt is made to set constraints on the otherwise ambiguous decomposition of the rotation curves of low surface brightness galaxies into contributions due to the various components of the galaxies. For this purpose galaxies are selected which show ... More
Implications of modes of star formation for the overall dynamics of galactic disksMar 22 2001One of the present concepts for the onset of massive star formation is the Kennicutt criterion. This relates the onset of massive star formation to a general gravitational instability of the gas disks of spiral galaxies. It is often overlooked, however ... More
Trans-Planckian Tail in a Theory with a CutoffJun 28 1996Trans-planckian frequencies can be mimicked outside a black-hole horizon as a tail of an exponentially large amplitude wave that is mostly hidden behind the horizon. The present proposal requires implementing a final state condition. This condition involves ... More
Unitary Evolution Between Pure and Mixed StatesApr 26 1995Dec 19 1995We propose an extended quantum mechanical formalism that is based on a wave operator $\vr$, which is related to the ordinary density matrix via $\rho=\vr\vr^\dagger$. This formalism allows a (generalized) unitary evolution between pure and mixed states. ... More