Results for "E. Cucchetti"

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Towards mapping turbulence in the intra-cluster medium -- I. Sample variance in spatially-resolved X-ray line diagnosticsApr 12 2019X-ray observations of galaxy clusters provide insights on the nature of gaseous turbulent motions, their physical scales and on the fundamental processes they are related to. Spatially-resolved, high-resolution spectral measurements of X-ray emission ... More
Towards mapping the turbulence in the intra-cluster medium -- II. Measurement uncertainties in the estimation of structure functionsApr 12 2019X-ray observations of the hot gas filling the intra-cluster medium provide a wealth of information on the dynamics of clusters of galaxies. The global equilibrium of the ICM is believed to be partially ensured by non-thermal pressure support, notably ... More
Measuring turbulence and gas motions in galaxy clusters via synthetic Athena X-IFU observationsMay 07 2018Jul 18 2018The X-ray Integral Field Unit (X-IFU) that will be on board the Athena telescope will provide an unprecedented view of the intracluster medium (ICM) kinematics through the observation of gas velocity, $v$, and velocity dispersion, $w$, via centroid-shift ... More
Energy scale calibration and drift correction of the X-IFUJul 04 2018The Athena X-Ray Integral Field Unit (X-IFU) will provide spatially resolved high-resolution spectroscopy (2.5 eV FWHM up to 7 keV) over the 0.2 to 12 keV energy band. It will comprise an array of 3840 superconducting Transition Edge Sensors (TESs) operated ... More
Athena X-IFU synthetic observations of galaxy clusters to probe the chemical enrichment of the UniverseSep 24 2018Answers to the metal production of the Universe can be found in galaxy clusters, notably within their Intra-Cluster Medium (ICM). The X-ray Integral Field Unit (X-IFU) on board the next-generation European X-ray observatory Athena (2030s) will provide ... More
Testing the X-IFU calibration requirements: an example for quantum efficiency and energy resolutionJul 04 2018With its array of 3840 Transition Edge Sensors (TESs) operated at 90 mK, the X-Ray Integral Field Unit (X-IFU) on board the ESA L2 mission Athena will provide spatially resolved high-resolution spectroscopy (2.5 eV FWHM up to 7 keV) over the 0.2 to 12 ... More
Probing Macro-Scale Gas Motions and Turbulence in Diffuse Cosmic PlasmasMar 11 2019Mar 14 2019Clusters of galaxies, the largest collapsed structures in the Universe, are located at the intersection of extended filaments of baryons and dark matter. Cosmological accretion onto clusters through large scale filaments adds material at cluster outskirts. ... More
Reproducibility and monitoring of the instrumental particle background for the X-Ray Integral Field UnitJul 04 2018The X-ray Integral Field Unit (X-IFU) is the cryogenic imaging spectrometer on board the future X-ray observatory \textsl{Athena}. With a hexagonal array of 3840 AC-biased Transition Edge Sensors (TES), it will provide narrow-field observations (5$^{\prime}$ ... More
Bogoliubov sound speed in periodically modulated Bose-Einstein condensatesAug 11 2003We study the Bogoliubov excitations of a Bose-condensed gas in an optical lattice. Of primary interest is the long wavelength phonon dispersion for both current-free and current-carrying condensates. We obtain the dispersion relation by carrying out a ... More
Intergalactic Gas in Groups of Galaxies: Implications for Dwarf Spheroidal Formation and The Missing Baryons ProblemJul 05 2011Radio galaxies with bent jets are predominantly located in groups and clusters of galaxies. We use bent-double radio sources, under the assumption that their jets are bent by ram-pressure, to probe intragroup medium (IGM) gas densities in galaxy groups. ... More
Bent-Double Radio Sources as Probes of the Intragroup MediumJul 25 2007Galaxy groups likely contain a significant fraction of the total baryonic mass in the local universe within their intragroup medium (IGM). However, aside from a handful of UV absorption line and X-ray observations, almost nothing is known about the IGM. ... More
Top Quarks at Photon CollidersSep 08 2000A review of results on top quark physics expected at the Photon Linear Colliders is presented.
The circumnuclear environment of IRAS 20551-4250 a case study of AGN/Starburst connection for JWSTDec 21 2011We present a general review of the current knowledge of IRAS 20551-4250 and its circumnuclear environment. This Ultraluminous Infrared Galaxy is one of the most puzzling sources of its class in the nearby Universe: the near-IR spectrum is typical of a ... More
Type-I superconductivity in ScGa3 and LuGa3 single crystalsMay 30 2012We present evidence of type-I superconductivity in single crystals of ScGa3 and LuGa3, from magnetization, specific heat, and resistivity measurements: low critical temperatures Tc = 2.1-2.2 K; field-induced secondto first-order phase transition in the ... More
A new evolution equationMar 20 1995We propose a new evolution equation for the gluon density relevant for the region of small $x_B$. It generalizes the GLR equation and allows deeper penetration in dense parton systems than the GLR equation does. This generalization consists of taking ... More
Self-Dual Supergravity Theories in 2+2 DimensionsJun 26 1992Starting from the new minimal multiplet of supergravity in $2+2$ dimensions, we construct two types of self-dual supergravity theories. One of them involves a self-duality condition on the Riemann curvature and implies the equations of motion following ... More
Twistor-like Formulation of Super p-BranesDec 21 1993Closed super (p+2)-forms in target superspace are relevant for the construction of the usual super p-brane actions. Here we construct closed super (p+1)-forms on a {\it worldvolume superspace}. They are built out of the pull-backs of the Kalb-Ramond super ... More
Exact exponential bounds for the random field maximum distribution via the majoring measures (generic chaining)Feb 04 2008In this paper non-asymptotic exact exponential estimates are derived for the tail of maximum distribution of random field in the terms of majoring measures or, equally, generic chaining.
A Subjective Approach to Quantum ProbabilityMar 06 2005A likelihood order is defined over linear subspaces of a finite dimensional Hilbert space. It is shown that such an order that satisfies some plausible axioms can be represented by a quantum probability in two cases: pure state and uniform measure.
Gauge Invariant Classes of Feynman Diagrams and Applications for CalculationsJan 24 2001In theories like SM or MSSM with a complex gauge group structure the complete set of Feynman diagrams contributed to a particular physics process can be splited to exact gauge invariant subsets. Arguments and examples given in the review demonstrate that ... More
Off shell pi N amplitude and the p p->p p pi0 reactionMar 21 1995We have used a conventional model for the $pp \rightarrow pp \pi^{0}$ reaction consisting of the Born term plus the $s$-wave rescattering term. As a novelty we have introduced the off shell dependence of the $\pi N$ $s$-wave isoscalar amplitude. This ... More
A question in the axiomatic approach to Quantum MechanicsJul 09 2004The classical Hilbert space formulation of the axioms of Quantum Mechanics appears to leave open the question whether the Hermitian operators which are associated with the observables of a finite non-relativistic quantum system are uniquely determined. ... More
Tame division algebras of prime period over function fields of $p$-adic curvesMar 09 2010Mar 30 2012Let F be a field of transcendence degree one over a p-adic field, and let l be a prime not equal to p. Results of Merkurjev and Saltman show that H^2(F,\mu_l) is generated by Z/l-cyclic classes. We prove the "Z/l-length" in H^2(F,\mu_l) equals the l-Brauer ... More
Functional limit theorems for Levy processes and their almost-sure versionsAug 07 2009In this paper we prove a criterion of convergence in distribution in Skorokhod space. We apply this criterion to some special Levy processes and obtain almost-sure versions of limit theorems for these processes.
Topologies and all that -- A TutorialMar 03 2015This is a brief introduction to the basic concepts of topology. It includes the basic constructions, discusses separation properties, metric and pseudometric spaces, and gives some applications arising from the use of topology in computing.
Mesonic and Binding Contributions to the Nuclear Drell-Yan ProcessDec 01 1997We have evaluated the Drell-Yan cross section in nuclei paying special attention to the meson cloud contribution from pion and rho-meson, for which an accurate calculation using the meson nuclear spectral functions is used. Similarly, the nucleonic contribution ... More
On the stationarity of linearly forced turbulence in finite domainsApr 28 2011May 08 2011A simple scheme of forcing turbulence away from decay was introduced by Lundgren some time ago, the `linear forcing', which amounts to a force term linear in the velocity field with a constant coefficient. The evolution of linearly forced turbulence towards ... More
On non-linear superfield versions of the vector-tensor multipletNov 06 1997Jan 30 1998We propose a harmonic superspace description of the non-linear vector-tensor N=2 multiplet. We show that there exist two inequivalent version: the old one in which one of the vectors is the field-strength of a gauge two-form, and a new one in which this ... More
Chiral fermion action with (8,0) worldsheet supersymmetryJun 13 1994We propose an action describing chiral fermions with an arbitrary gauge group and with manifest $(8,0)$ worldsheet supersymmetry. The form of the action is inspired by and adapted for completing the twistor-like formulation of the $D=10$ heterotic superstring. ... More
Limits on Expanding Relativistic Shells from Gamma-Ray Burst Temporal StructureMay 06 1997We calculate the expected envelope of emission for relativistic shells under the assumption of local spherical symmetry. Gamma-Ray Burst envelopes rarely conform to the expected shape, which is similar to a FRED; a fast rise and exponential decay. The ... More
Thermal radiation and inclusive production in the CGC/saturation approach at high energiesFeb 21 2019In this paper, we discuss the inclusive production of hadrons in the framework of CGC/saturation approach. We argue, that the gluon jet inclusive production stems from the vicinity of the saturation momentum, even for small values of the transverse momenta ... More
Super p-Brane Theories and New Spacetime SuperalgebrasApr 26 1995We present a geometric formulation of super $p$--brane theories in which the Wess--Zumino term is $(p+1)$--th order in the supersymmetric currents, and hence is manifestly supersymmetric. The currents are constructed using a supergroup manifold corresponding ... More
Proximity effect and self-consistent field in a normal metal-superconductor structureMar 12 2019The concept of a self-consistent field in the theory of superconductivity based on the diagram method of the time-dependent perturbation theory is presented. It is shown that the well-known Bardeen-Cooper-Schrieffer equation for the order parameter of ... More
On certain definite integrals and infinite seriesSep 23 2013A translation of Kummer`s paper On certain definite integrals and infinite series
Quasielastic Versus Inelastic and Deep Inelastic Lepton Scattering in Nuclei at x > 1Dec 12 1996Feb 14 1997We have made a thorough investigation of the nuclear structure function W_2A in the region of 0.8 < x < 1.5 and Q^2 < 20 GeV^2, separating the quasielastic and inelastic plus deep inelastic contributions. The agreement with present experimental data is ... More
Isocalar Roper excitation in the pp --> pp pi0 reaction close to thresholdAug 07 1998A new mechanism for the pp --> pp pi0 reaction close to threshold is suggested coming from the isoscalar excitation of the Roper and its decay into N(pi pi)S-wave, with one of the pi0 emitted and the other one reabsorbed on the second nucleon. The mechanism ... More
Basics of Quantum Computation (Part 1)Jul 08 2004The aim of this textbook is to bridge in regard of quantum computation what proves to be a considerable threshold even to the usual science trained readership between the level of science popularization, and on the other hand, the presently available ... More
Perturbative QCD and beyond: azimuthal angle correlations in deuteron-deuteron scattering from Bose-Einstein correlationsNov 05 2016In this paper, we found within the framework of perturbative QCD, that in deuteron-deuteron scattering the Bose-Einstein correlations due to two parton showers production, induce azimuthal angle correlations, with three correlation lengths: the size of ... More
Gamma-Ray Burst Spectra and Time Histories from 2 to 400 keVFeb 12 1998The Gamma-Ray burst detector on Ginga consisted of a proportional counter to observe the x-rays and a scintillation counter to observe the gamma-rays. It was ideally suited to study the x-rays associated with gamma-ray bursts (GRBs). Ginga detected 120 ... More
A continuous analogue of the invariance principle and its almost sure versionAug 07 2009We deal with random processes obtained from a homogeneous random process with independent increments by replacement of the time scale and by multiplication by a norming constant. We prove the convergence in distribution of these processes to Wiener process ... More
How to solve smooth nonlinear PDEs in algebras of generalized functions with dense singularitiesJun 29 2004As a significant strengthening of properties of earlier algebras of generalized functions, here are presented classes of such algebras which can deal with dense singularities. In fact, the cardinal of the set of singular points can be larger than that ... More
A set-indexed fractional Brownian motionMar 11 2005Feb 06 2006We define and prove the existence of a fractional Brownian motion indexed by a collection of closed subsets of a measure space. This process is a generalization of the set-indexed Brownian motion, when the condition of independance is relaxed. Relations ... More
Temporal Evolution of the Pulse Width in GRBsDec 23 1998Many cosmological models of GRBs envision the energy source to be a cataclysmic stellar event leading to a relativistically expanding fireball. Particles are thought to be accelerated at shocks and produce nonthermal radiation. The highly variable temporal ... More
The Observational Basis for Central Engines in Gamma Ray BurstsJun 08 1999We review the observational differences between gamma-ray bursts occurring on a single shell (such as in the external shock model) and multiple shells (such as in the internal shock model). We do not argue against external shocks or for internal shocks, ... More
Couplings of self-dual tensor multiplet in six dimensionsMay 13 1996The (1,0) supersymmetry in six dimensions admits a tensor multiplet which contains a second-rank antisymmetric tensor field with a self-dual field strength and a dilaton. We describe the fully supersymmetric coupling of this multiplet to Yang-Mills multiplet, ... More
Pulse Width Evolution in GRBs: Evidence for Internal ShocksOct 14 1999Aug 17 2000Many cosmological models of GRBs envision the energy source to be a cataclysmic stellar event leading to a relativistically expanding fireball. Particles are thought to be accelerated at shocks and produce nonthermal radiation. The highly variable temporal ... More
Gamma-Ray Bursts as Internal Shocks Caused By DecelerationSep 17 1999Gamma-ray bursts (GRBs) have been thought to originate from internal shocks that occur about 10^{15} cm from a central site. The shells responsible for these shocks merge together and undergo an external shock at about 10^{17} cm, producing the afterglows. ... More
The Dispersal of Young Stars and the Greater Sco-Cen AssociationMay 16 2001We review topics related to the dispersal of young stars from their birth-sites, and focus in particular on the entourage of young stars related to the ongoing star-formation event in the Sco-Cen OB association. We conduct a follow-up kinematic study ... More
The conformal transformation of the night skyJun 24 2016We give a simple differential geometric proof of the conformal transformation of the night sky under change of observer. The proof does not rely on the four dimensionality of spacetime or on spinor methods. Furthermore, it really shows that the result ... More
Spectral properties of weighted line digraphsJun 09 2015In this paper, we treat some weighted line digraphs which are induced by a connected and undirected graph. For a given graph $G$, the adjacency matrix of the weighted line digraph $W$ is determined by a boundary operator from an arc-based space to a vertex-based ... More
A Hardware Implementation of Artificial Neural Network Using Field Programmable Gate ArraysMar 05 2007An artificial neural network algorithm is implemented using a field programmable gate array hardware. One hidden layer is used in the feed-forward neural network structure in order to discriminate one class of patterns from the other class in real time. ... More
Semileptonic b to u transitionFeb 12 2007Experimental studies of charmless semileptonic B decays can be broadly categorized into inclusive and exclusive measurements depending on how the final states are treated. The inclusive method measures the decay rate $\Gamma(B \to X_u \ell \nu)$, where ... More
Reply to the comment by D. Gorokhov cond-mat/0502083Feb 09 2005We show that the recent comment by D. Gorokhov, is based on physically obvious errors and misunderstandings of the content of the criticized papers and is readily refuted. We show that 1) In our paper [1] there were considered situations of both strong ... More
Supersymmetric radiative corrections to neutrino indices of refractionJun 02 1995We compute the one-loop effects on the neutrino propagation through matter induced by virtual supersymmetric particles. We show that, in the minimal version of the supersymmetric standard model, a non-degeneracy between sleptons of the second and third ... More
Spiralicity and Motion on Cosmic ScaleJun 25 2014We hypothesize a simple scenario to associate spiral-shaped trajectories and asymptotic tangential velocities according to observations found on deep space scales. As a difference with alternative Modified Newton Dynamics (MoND), in our scenario the dynamics ... More
Special relativity as the limit of an Aristotelian universal friction theory under Reye's assumptionNov 28 2014This work explores a classical mechanical theory under two further assumptions: (a) there is a universal dry friction force (Aristotelian mechanics), and (b) the variation of the mass of a body due to wear is proportional to the work done by the friction ... More
Interactions between hadrons are strongly modified near the QCD (tri)critical pointApr 06 2005The QCD (tri)critical point, a genuine second-order phase transition, implies existence of a massless scalar mode, and singular behavior near it. In this work we however focus on the finite region around it, defined by a condition $m_\sigma=2m_\pi$. We ... More
Convexity and quasi-uniformizability of closed preordered spacesDec 16 2012Mar 17 2013In many applications it is important to establish if a given topological preordered space has a topology and a preorder which can be recovered from the set of continuous isotone functions. Under antisymmetry this property, also known as quasi-uniformizability, ... More
Functional spaces and operators connected with some Lévy noisesAug 15 2006We review some recent developments in white noise analysis and quantum probability. We pay a special attention to spaces of test and generalized functionals of some L\'evy white noises, as well as as to the structure of quantum white noise on these spaces. ... More
The Associated Metric for a Particle in a Quantum Energy LevelMar 24 1997Jul 04 1997We show that the probabilistic distribution over the space in the spectator world, can be associated via noncommutative geometry (with some modifications) to a metric in which the particle lives. According to this geometrical view, the metric in the particle ... More
On the Possibility of an Astronomical Perspective in the Study of Human EvolutionDec 05 2013The Sapient Paradox is the apparently unexplainable time delay of several ten thousand years following the arrival of Homo sapiens in Asia and Europe and before the introduction of impressive innovations with the agricultural revolution. Renfrew (2007) ... More
Bonaparte and the astronomers of Brera ObservatoryMay 27 2014In Northern Italy, between 1796 and 1814, Napoleon Bonaparte formed a Republic, and then a Kingdom, controlled by France. Milan was the capital of the State, and the Brera Palace was the main cultural centre, as regards both the arts and the sciences. ... More
Fractional transport equations for Levy stable processesOct 21 2000The influence functional method of Feynman and Vernon is used to obtain a quantum master equation for a Brownian system subjected to a Levy stable random force. The corresponding classical transport equations for the Wigner function are then derived, ... More
Effect of initial correlations on short-time decoherenceAug 27 2002We study the effect of initial correlations on the short-time decoherence of a particle linearly coupled to a bath of harmonic oscillators. We analytically evaluate the attenuation coefficient of a Schroedinger cat state both for a free and a harmonically ... More
Non-Bilocal Measurement via Entangled StateJan 03 2005Sep 27 2005Two observers, who share a pair of particles in an entangled mixed state, can use it to perform some non-bilocal measurement over another bipartite system. In particular, one can construct a specific game played by the observers against a coordinator, ... More
Bethe vectors of gl(3)-invariant integrable models, their scalar products and form factorsJan 17 2014This short note corresponds to a talk given at "Lie Theory and Its Applications in Physics", (Varna, Bulgaria, June 2013) and is based on joint works with S. Belliard, S. Pakuliak and N. Slavnov, see arXiv:1206.4931, arXiv:1207.0956, arXiv:1210.0768, ... More
W-strings from N=2 Hamiltonian reduction and classification of N=2 super W-algebrasDec 06 1996We present an algebraic approach to string theory, using a Hamiltonian reduction of N=2 WZW models. An embedding of sl(1|2) in a Lie superalgebra determines a niltopent subalgebra. Chirally gauging this subalgebra in the corresponding WZW action leads ... More
Detecting population III galaxies with HST and JWSTJun 25 2012A small fraction of the atomic-cooling halos assembling at z<15 may form out of minihalos that never experienced any prior star formation, and could in principle host small galaxies of chemically unenriched stars. Since the prospects of detecting isolated ... More
Probing the Mass Distribution with IRAS GalaxiesOct 29 2001We present the results of three independent analyses in which we show that IRAS galaxies faithfully trace the underlying distribution the mass in the local universe. In the first analysis we compare the mass and the galaxy density fields and show that ... More
Vertical Shearing Instabilities in Radially Shearing Disks: The Dustiest Layers of the Protoplanetary NebulaNov 28 2007Gravitational instability of a vertically thin, dusty sheet near the midplane of a protoplanetary disk has long been proposed as a way of forming planetesimals. Before Roche densities can be achieved, however, the dust-rich layer, sandwiched from above ... More
Electroweak Corrections to t-channel single top production at the LHCNov 13 2008We describe the computation of the $\mathcal{O}(\alpha^3)$ corrections for single top (and single anti-top) production in the $t$-channel at hadron colliders. We show also The genuine one loop SUSY contribution to these processes. Such contributions are ... More
Fixing the fixed-point system - Applying Dynamic Renormalization Group to systems with long-range interactionsOct 25 2007Nov 04 2012In this paper a mode of using the Dynamic Renormalization Group (DRG) method is suggested in order to cope with inconsistent results obtained when applying it to a continuous family of one-dimensional nonlocal models. The key observation is that the correct ... More
p-Brane and D-Brane ActionsJul 31 1996We consider the actions for ten--dimensional $p$--branes and $D$--branes in an arbitrary curved background and discuss some of their properties. We comment on how the $SL(2,R)$ duality symmetry acts on the five--brane actions.
Electron-phonon effects on the Raman spectrum in MgB$_2$Dec 09 2005Apr 29 2006The anomalous features of the Raman spectroscopy measurement in MgB$_2$ represent a still unresolved puzzle. In particular highly debated are the origin of the huge $E_{2g}$ phonon linewidth, the nature of the low energy ($\omega < \omega_{E_{2g}}$) background ... More
Contribution of pulsars to the gamma-ray background and their observation with the space telescopes GLAST and AGILEMar 24 2005Luminosities and uxes of the expected population of galactic gamma-ray pulsars become foreseeable if physical distributions at birth and evolutive history are assigned. In this work we estimate the contribution of pulsar uxes to the gamma-ray background, ... More
Rotating Black Hole Solutions with Axion Dilaton and Two Vector Fields and Solutions with Metric and Fields of the Same FormMay 15 2009We present two rotating black hole solutions with axion $\xi$, dilaton $\phi$ and two U(1) vector fields. By applying the "Newman-Janis trick" to a metric with 3 arbitrary parameters we find a rotating metric $g_{\mu\nu}$ with 4 such parameters $(M, a, ... More
Brane Inflation from Mirage CosmologyNov 08 2000We study the cosmological evolution of a D3-brane universe in a type 0 string background. We follow the brane-universe along the radial coordinate of the background and we calculate the energy density which is induced on the brane because of its motion ... More
Flaring Up All Over -- Radio Activity in Rapidly-Rotating Late-Type M and L DwarfsNov 16 2001Mar 01 2002We present Very Large Array observations of twelve late M and L dwarfs in the Solar neighborhood. The observed sources were chosen to cover a wide range of physical characteristics - spectral type, rotation, age, binarity, and X-ray and H\alpha activity ... More
Transport properties of fermionic systemsFeb 01 1999Feb 14 1999We extend the method discovered by A Y Alekseev et al to the case of fermions in external fields. A general formula for conductance G is proved. In the (1+1)-D case with symmetry at time reflection, it is shown that: G=e^2/h+o(a^), where a is the strength ... More
Transfer matrices for scalar fields on curved spacesJan 12 1999Jan 20 1999We apply Nelson's technique of constructing Euclidean fields to the case of classical scalar fields on curved spaces. It is shown how to construct a transfer matrix and, for a class of metrics, the basic spectral properties of its generator are investigated. ... More
Nearsightedness of Electronic Matter in One DimensionJun 27 2005Dec 01 2005The concept of nearsightedeness of electronic matter (NEM) was introduced by W. Kohn in 1996 as the physical principal underlining Yang's electronic structure alghoritm of divide and conquer. It describes the fact that, for fixed chemical potential, local ... More
Symmetry breaking in the self-consistent Kohn-Sham equationsFeb 02 2005Jun 08 2005The Kohn-Sham (KS) equations determine, in a self-consistent way, the particle density of an interacting fermion system at thermal equilibrium. We consider a situation when the KS equations are known to have a unique solution at high temperatures and ... More
The phase diagram for the $(λφ^{4}+σφ^{2})_{2}$ modelApr 16 2002The two parameter model is reduced to a one parameter model by using simple transformations. Because the separation between different phase regions for a one parameter model is just a point, the equivalence between the two models leads to the exact equation ... More
Gaussian, Mean Field and Variational Approximation: the EquivalenceMay 26 1999We show the equivalence between the three approximation schemes for self-interacting (1+1)-D scalar field theories. Based on rigorous results of [1, 2], we are able to prove that the Gaussian approximation is very precise for certain limits of coupling ... More
Spontaneous Transitions in Quantum MechanicsFeb 01 1999May 14 1999The problem of spontaneous pair creation in static external fields is reconsidered. A weak version of the conjecture proposed by G Nenciu (1980) is seated and proved. The method reduces the proof of the general conjecture to the study of the evolution, ... More
On Geometric Infinite Divisibility p-thinning and Cox ProcessesSep 21 2014We discuss the connections among geometric infinite divisibility, thinning of renewal processes and Cox processes in this paper.
Predictions for Gromov-Witten invariants of noncommutative resolutionsDec 21 2012Apr 23 2013In this paper, we apply recent methods of localized GLSMs to make predictions for Gromov-Witten invariants of noncommutative resolutions, as defined by e.g. Kontsevich, and use those predictions to examine the connectivity of the SCFT moduli space. Noncommutative ... More
GLSM's, gerbes, and Kuznetsov's homological projective dualityApr 29 2010In this short note we give an overview of recent work on string propagation on stacks and applications to gauged linear sigma models. We begin by outlining noneffective orbifolds (orbifolds in which a subgroup acts trivially) and related phenomena in ... More
Extremal Transitions in Heterotic String TheoryMay 27 1997Jun 05 1997In this paper we study extremal transitions between heterotic string compactifications, i.e., transitions between pairs (M,V) where M is a Calabi-Yau manifold and V a gauge bundle. Bundle transitions are described using language recently espoused by Friedman, ... More
Notes on correlation functions in (0,2) theoriesFeb 05 2005In this note we shall review recent work on generalizing rational curve counting to perturbative heterotic theories.
Notes on Bundles on K3sJun 02 1998In this technical note we describe a new (to the physics literature) construction of bundles on Calabi-Yaus. We primarily study this construction in the special case of K3 surfaces, for which interesting results can be obtained. For example, we use this ... More
Geometric zero mode for the Kraichnan's problem of passive scalar advectionSep 12 1996We find explicitly a zero mode of the Kraichnan operator at two dimensions.
An action for N=4 supersymmetric self-dual Yang-Mills theorySep 18 1995The $N=4$ supersymmetric self-dual Yang-Mills theory in a four- dimensional space with signature $(2,2)$ is formulated in harmonic superspace. The on-shell constraints of the theory are reformulated in the equivalent form of vanishing curvature conditions ... More
NNLO Analysis Of Semileptonic Rare B DecaysMay 14 2002We update the standard model predictions for the branching ratios of the decays B -> (K,K*,Xs) l^+ l^-, with l=e,mu. Using the measurements of BR(B -> Xs gamma) and BR(B -> K l^+ l^-) as well as the upper limits on BR(B -> (K*,Xs) l^+ l^-)$, we work out ... More
Extended Minimal Flavour Violating MSSMAug 07 2001The recently reported measurements of the CP asymmetry a(psi K) by the BABAR and BELLE collaborations are in good agreement with the standard model prediction. With the anticipated precision in a(psi K) at the B factories and hadron colliders, one hopes ... More
The scientific use and productivity of the Telescopio Nazionale Galileo (TNG)Dec 11 2008This paper reviews the scientific use of the TNG from the beginning of regular observations till the end of 2007. Statistics are given for the time request, use and productivity of the telescope and its focal plane instruments. Information on the down-times ... More
The AMANDA Neutrino Telescope: Principle of Operation and First ResultsJun 11 1999AMANDA is a high-energy neutrino telescope presently under construction at the geographical South Pole. In the Antarctic summer 1995/96, an array of 80 optical modules (OMs) arranged on 4 strings (AMANDA-B4) was deployed at depths between 1.5 and 2 km. ... More
Critical generalized inverse participation ratio distributionsApr 09 2002Dec 11 2002The system size dependence of the fluctuations in generalized inverse participation ratios (IPR's) $I_{\alpha}(q)$ at criticality is investigated numerically. The variances of the IPR logarithms are found to be scale-invariant at the macroscopic limit. ... More
Giant Molecular Clouds in M31: I - Molecular Cloud PropertiesSep 14 2006We present Berkeley Illinois Maryland Association (BIMA) millimeter interferometer observations of giant molecular clouds (GMCs) along a spiral arm in M31. The observations consist of a survey using the compact configuration of the interferometer and ... More
On the Existence of Spacetime StructureMar 11 2015I examine the debate between substantivalists and relationalists about the ontological character of spacetime and conclude it is not well posed. I argue that the so-called Hole Argument does not bear on the debate, because it provides no clear criterion ... More