Results for "D. Caprioli"

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Nonlinear shock acceleration and gamma-ray emission from Tycho and KeplerOct 01 2012We apply the non-linear diffusive shock acceleration theory in order to describe the properties of two supernova remnants, SN 1572 (Tycho) and SN 1604 (Kepler). By analyzing the multi-wavelength spectra, we infer that both Tycho's and Kepler's forward ... More
Cosmic-ray-induced filamentation instability in collisionless shocksNov 28 2012Feb 13 2013We used unprecedentedly large 2D and 3D hybrid (kinetic ions - fluid electrons) simulations of non-relativistic collisionless strong shocks in order to investigate the effects of self-consistently accelerated ions on the overall shock dynamics. The current ... More
Strong evidences of hadron acceleration in Tycho's Supernova RemnantMay 31 2011Oct 19 2011Very recent gamma-ray observations of G120.1+1.4 (Tycho's) supernova remnant (SNR) by Fermi-LAT and VERITAS provided new fundamental pieces of information for understanding particle acceleration and non-thermal emission in SNRs. We want to outline a coherent ... More
Novae as Tevatrons: Prospects for CTA and IceCubeOct 26 2015The discovery of novae as sources of ~GeV gamma-rays highlights the key role of shocks and relativistic particle acceleration in these transient systems. Although there is evidence for a spectral cut-off above energies ~1-100 GeV at particular epochs ... More
Non-linear diffusive shock acceleration with free escape boundaryDec 14 2009May 11 2010We present here a semi-analytical solution of the problem of particle acceleration at non-linear shock waves with a free escape boundary at some location upstream. This solution, besides allowing us to determine the spectrum of particles accelerated at ... More
On the escape of particles from cosmic ray modified shocksJul 26 2008Feb 02 2009Stationary solutions to the problem of particle acceleration at shock waves in the non-linear regime, when the dynamical reaction of the accelerated particles on the shock cannot be neglected, are known to show a prominent energy flux escaping from the ... More
Gamma-Rays from Heavy Nuclei Accelerated in Supernova RemnantsNov 30 2010We investigate the theoretical and observational implications of the acceleration of protons and heavier nuclei in supernova remnants (SNRs). By adopting a semi-analytical technique, we study the non-linear interplay among particle acceleration, magnetic ... More
Non-linear diffusive acceleration of heavy nuclei in supernova remnant shocksJul 12 2010Nov 09 2010We describe a semi-analytical approach to non-linear diffusive shock acceleration in the case in which nuclei other than protons are also accelerated. The structure of the shock is determined by the complex interplay of all nuclei, and in turn this shock ... More
The contribution of supernova remnants to the galactic cosmic ray spectrumDec 15 2009Jul 27 2010The supernova paradigm for the origin of galactic cosmic rays has been deeply affected by the development of the non-linear theory of particle acceleration at shock waves. Here we discuss the implications of applying such theory to the calculation of ... More
Collisionless shocks in a partially ionized medium: III. Efficient cosmic ray accelerationNov 26 2012Mar 19 2013In this paper we present the first formulation of the theory of non-linear particle acceleration in collisionless shocks in the presence of neutral hydrogen in the acceleration region. The dynamical reaction of the accelerated particles, the magnetic ... More
Dynamical Feedback of Self-generated Magnetic Fields in Cosmic Ray Modified ShocksJul 26 2008Feb 02 2009We present a semi-analytical kinetic calculation of the process of non-linear diffusive shock acceleration (NLDSA) which includes the magnetic field amplification due to cosmic ray induced streaming instability, the dynamical reaction of the amplified ... More
Collisionless shocks in a partially ionized medium: I. Neutral return flux and its effects on acceleration of test particlesFeb 14 2012Jun 19 2012A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged ... More
Comparison of Different Methods for Nonlinear Diffusive Shock AccelerationMay 12 2010Jul 27 2010We provide a both qualitative and quantitative comparison among different approaches aimed to solve the problem of non-linear diffusive acceleration of particles at shocks. In particular, we show that state-of-the-art models (numerical, Monte Carlo and ... More
Shock acceleration in partially neutral plasmasDec 14 2010We present the non-linear theory of shock acceleration applied to SNRs expanding into partially neutral plasma. Using this theory we show how the Balmer lines detected from young SNRs can be used to test the efficiency of shocks in the production of cosmic ... More
Spatial structure of X-ray filaments in SN 1006Dec 15 2009Mar 10 2010The theory of Non-Linear Diffusive Shock Acceleration (NLDSA) predicts the formation of a precursor upstream of the shock, where accelerated particles diffuse and induce magnetic field amplification through streaming instability. The non detection of ... More
Cosmic-ray acceleration in supernova remnants: non-linear theory revisedJun 06 2012A rapidly growing amount of evidences, mostly coming from the recent gamma-ray observations of Galactic supernova remnants (SNRs), is seriously challenging our understanding of how particles are accelerated at fast shocks. The cosmic-ray (CR) spectra ... More
An Original Mechanism for the Acceleration of Ultra-High-Energy Cosmic RaysApr 28 2017We suggest that ultra-high-energy (UHE) cosmic rays (CRs) may be accelerated in ultra-relativistic flows via a one-shot mechanism, the "espresso" acceleration, in which already-energetic particles are generally boosted by a factor of $\sim\Gamma^2$ in ... More
Cosmic-ray Acceleration and PropagationOct 23 2015The origin of cosmic rays (CRs) has puzzled scientists since the pioneering discovery by Victor Hess in 1912. In the last decade, however, modern supercomputers have opened a new window on the processes regulating astrophysical collisionless plasmas, ... More
New insights on hadron acceleration at supernova remnant shocksJan 31 2013We outline the main features of nuclei acceleration at supernova remnant forward shocks, stressing the crucial role played by self-amplified magnetic fields in determining the energy spectrum observed in this class of sources. In particular, we show how ... More
From E. Fermi to Fermi-LAT: watching particle acceleration in supernova remnantsMar 10 2013Supernova remnants (SNRs) have been regarded for many decades as the sources of Galactic cosmic rays (CRs) up to a few PeV. However, only with the advent of Fermi-LAT it has been possible to detect - at least in some SNRs - \gamma-rays whose origin is ... More
Fermi acceleration at supernova remnant shocksOct 02 2012We investigate the physics of particle acceleration at non-relativistic shocks exploiting two different and complementary approaches, namely a semi-analytic modeling of cosmic-ray modified shocks and large hybrid (kinetic protons/fluid electrons) simulations. ... More
Supernova remnants as cosmic ray factoriesMar 24 2011In this work we investigate particle acceleration in supernova remnant shocks within a semi-analytical formalism which self-consistently accounts for particle acceleration, amplification of the magnetic field via streaming instability and back-reaction ... More
SN 2016coi (ASASSN-16fp): an energetic H-stripped core-collapse supernova from a massive stellar progenitor with large mass lossMay 06 2019We present comprehensive observations and analysis of the energetic H-stripped SN 2016coi (a.k.a. ASASSN-16fp), spanning the $\gamma$-ray through optical and radio wavelengths, acquired within the first hours to $\sim$420 days post explosion. Our campaign ... More
"Espresso" Acceleration of Ultra-high-energy Cosmic RaysMay 25 2015Oct 05 2015We propose that ultra-high-energy (UHE) cosmic rays (CRs) above $10^{18}$eV are produced in relativistic jets of powerful active galactic nuclei via an original mechanism, which we dub "espresso" acceleration: "seed" galactic CRs with energies $\lesssim ... More
Understanding hadronic $γ$-ray emission from supernova remnantsNov 01 2011We aim to test the plausibility of a theoretical framework in which the $\gamma-$ray emission detected from supernova remnants is of hadronic origin, i.e., due to the decay of neutral pions produced in nuclear collisions involving relativistic nuclei. ... More
Understanding hadronic gamma-ray emission from supernova remnantsMar 14 2011May 06 2011We aim to test the plausibility of a theoretical framework in which the gamma-ray emission detected from supernova remnants may be of hadronic origin, i.e., due to the decay of neutral pions produced in nuclear collisions involving relativistic nuclei. ... More
Hybrid Simulations of Particle Acceleration at ShocksOct 07 2014We present the results of large hybrid (kinetic ions - fluid electrons) simulations of particle acceleration at non-relativistic collisionless shocks. Ion acceleration efficiency and magnetic field amplification are investigated in detail as a function ... More
Relativistic electrons produced by foreshock disturbancesJul 07 2016Foreshock disturbances -- large-scale (~1000 km to >30,000 km), transient (~5-10 per day - lasting ~10s of seconds to several minutes) structures [1,2] - generated by suprathermal (>100 eV to 100s of keV) ions [3,4] arise upstream of Earth's bow shock ... More
Simulations of Ion Acceleration at Non-relativistic Shocks. III. Particle DiffusionJul 08 2014Oct 07 2014We use large hybrid (kinetic protons-fluid electrons) simulations to investigate the transport of energetic particles in self-consistent electromagnetic configurations of collisionless shocks. In previous papers of this series, we showed that ion acceleration ... More
Simulations of Ion Acceleration at Non-relativistic Shocks. II. Magnetic Field AmplificationJan 29 2014Oct 07 2014We use large hybrid simulations to study ion acceleration and generation of magnetic turbulence due to the streaming of particles that are self-consistently accelerated at non-relativistic shocks. When acceleration is efficient, we find that the upstream ... More
Bottom-up Acceleration of Ultra-High-Energy Cosmic Rays in the Jets of Active Galactic NucleiApr 04 2019It has been proposed that Ultra-High-Energy Cosmic Rays (UHECRs) up to $10^{20}$eV could be produced in the relativistic jets of powerful Active Galactic Nuclei (AGNs) via a one-shot reacceleration of lower-energy CRs produced in supernova remnants (the ... More
Simulations of Ion Acceleration at Non-relativistic Shocks. I. Acceleration EfficiencyOct 10 2013Oct 07 2014We use 2D and 3D hybrid (kinetic ions - fluid electrons) simulations to investigate particle acceleration and magnetic field amplification at non-relativistic astrophysical shocks. We show that diffusive shock acceleration operates for quasi-parallel ... More
The maximum momentum of particles accelerated at cosmic ray modified shocksDec 15 2006Particle acceleration at non-relativistic shocks can be very efficient, leading to the appearance of non-linear effects due to the dynamical reaction of the accelerated particles on the shock structure and to the non-linear amplification of the magnetic ... More
Simultaneous Acceleration of Protons and Electrons at Nonrelativistic Quasiparallel Collisionless ShocksDec 01 2014Jan 29 2015We study diffusive shock acceleration (DSA) of protons and electrons at nonrelativistic, high Mach number, quasiparallel, collisionless shocks by means of self-consistent 1D particle-in-cell simulations. For the first time, both species are found to develop ... More
Simulations and Theory of Ion Injection at Non-relativistic Collisionless ShocksSep 29 2014Dec 04 2014We use kinetic hybrid simulations (kinetic ions - fluid electrons) to characterize the fraction of ions that are accelerated to non-thermal energies at non-relativistic collisionless shocks. We investigate the properties of the shock discontinuity and ... More
Chemical Enhancements in Shock-accelerated Particles: Ab-initio SimulationsApr 26 2017We study the thermalization, injection, and acceleration of ions with different mass/charge ratios, $A/Z$, in non-relativistic collisionless shocks via hybrid (kinetic ions-fluid electrons) simulations. In general, ions thermalize to a post-shock temperature ... More
Electron energy partition across interplanetary shocks: I. Methodology and Data ProductFeb 04 2019Mar 01 2019Analysis of 15314 electron velocity distribution functions (VDFs) within $\pm$2 hours of 52 interplanetary (IP) shocks observed by the \emph{Wind} spacecraft near 1 AU are introduced. The electron VDFs are fit to the sum of three model functions for the ... More
Electron energy partition across interplanetary shocks: I. Methodology and Data ProductFeb 04 2019Analysis of 15314 electron velocity distribution functions (VDFs) within $\pm$2 hours of 52 interplanetary (IP) shocks observed by the \emph{Wind} spacecraft near 1 AU are introduced. The electron VDFs are fit to the sum of three model functions for the ... More
Electron energy partition across interplanetary shocks: I. Methodology and Data ProductFeb 04 2019Apr 09 2019Analysis of 15314 electron velocity distribution functions (VDFs) within $\pm$2 hours of 52 interplanetary (IP) shocks observed by the \emph{Wind} spacecraft near 1 AU are introduced. The electron VDFs are fit to the sum of three model functions for the ... More
Electron energy partition across interplanetary shocks: I. Methodology and Data ProductFeb 04 2019May 02 2019Analysis of 15314 electron velocity distribution functions (VDFs) within $\pm$2 hours of 52 interplanetary (IP) shocks observed by the \emph{Wind} spacecraft near 1 AU are introduced. The electron VDFs are fit to the sum of three model functions for the ... More
Speeding up complex multivariate data analysis in Borexino with parallel computing based on Graphics Processing UnitMay 28 2018A spectral fitter based on the graphics processor unit (GPU) has been developed for Borexino solar neutrino analysis. It is able to shorten the fitting time to a superior level compared to the CPU fitting procedure. In Borexino solar neutrino spectral ... More
Improved measurement of 8B solar neutrinos with 1.5 kt y of Borexino exposureSep 03 2017We report on an improved measurement of the $^8$B solar neutrino interaction rate with the Borexino detector at the Laboratori Nazionali del Gran Sasso. Neutrinos are detected via their elastic scattering on electrons in a large, radio-pure liquid scintillator ... More
Limiting neutrino magnetic moments with Borexino Phase-II solar neutrino dataJul 28 2017Aug 10 2017A search for the solar neutrino effective magnetic moment has been performed using data from 1291.5 days exposure during the second phase of the Borexino experiment. No significant deviations from the expected shape of the electron recoil spectrum from ... More
Magnetohydrodynamic-Particle-in-Cell Method for Coupling Cosmic Rays with a Thermal Plasma: Application to Non-relativistic ShocksDec 02 2014Jun 24 2015We formulate a magnetohydrodynamic-particle-in-cell (MHD-PIC) method for describing the interaction between collisionless cosmic ray (CR) particles and a thermal plasma. The thermal plasma is treated as a fluid, obeying equations of ideal MHD, while CRs ... More
Seasonal Modulation of the $^7$Be Solar Neutrino Rate in BorexinoJan 27 2017May 24 2017We detected the seasonal modulation of the $^7$Be neutrino interaction rate with the Borexino detector at the Laboratori Nazionali del Gran Sasso in Italy. The period, amplitude, and phase of the observed time evolution of the signal are consistent with ... More
Modulations of the Cosmic Muon Signal in Ten Years of Borexino DataAug 13 2018Jan 28 2019We have measured the flux of cosmic muons in the Laboratori Nazionali del Gran Sasso at 3800\,m\,w.e. to be $(3.432 \pm 0.003)\cdot 10^{-4}\,\mathrm{{m^{-2}s^{-1}}}$ based on ten years of Borexino data acquired between May 2007 and May 2017. A seasonal ... More
The Monte Carlo simulation of the Borexino detectorApr 07 2017We describe the Monte Carlo (MC) simulation package of the Borexino detector and discuss the agreement of its output with data. The Borexino MC 'ab initio' simulates the energy loss of particles in all detector components and generates the resulting scintillation ... More
Kinetic simulations of mildly relativistic shocks I: particle acceleration in high Mach number shocksSep 28 2018We use fully kinetic particle-in-cell simulations with unprecedentedly large transverse box sizes to study particle acceleration in weakly-magnetized mildly relativistic shocks traveling at a velocity $\approx 0.75c$ and a Mach number of 15. We examine ... More
Dynamical effects of self-generated magnetic fields in cosmic ray modified shocksApr 17 2008Apr 17 2008Recent observations of greatly amplified magnetic fields ($\delta B/B\sim 100$) around supernova shocks are consistent with the predictions of the non-linear theory of particle acceleration (NLT), if the field is generated upstream of the shock by cosmic ... More
[Plasma 2020 Decadal] Multipoint Measurements of the Solar Wind: A Proposed Advance for Studying Magnetized TurbulenceMar 13 2019A multi-institutional, multi-national science team will soon submit a NASA proposal to build a constellation of spacecraft to fly into the near-Earth solar wind in a swarm spanning a multitude of scales in order to obtain critically needed measurements ... More
Supernova Remnants in the Local Group I: A model for the radio luminosity function and visibility times of supernova remnantsMay 16 2016Oct 07 2016Supernova remnants (SNRs) in Local Group galaxies offer unique insights into the origin of different types of supernovae. In order to take full advantage of these insights, one must understand the intrinsic and environmental diversity of SNRs in the context ... More
Plasma 2020 - Intracluster Medium PlasmasMar 20 2019Galaxy clusters are the largest and most massive bound objects resulting from cosmic hierarchical structure formation. Baryons account for somewhat more than 10% of that mass, with roughly 90% of the baryonic matter distributed throughout the clusters ... More
[Plasma 2020 Decadal] The essential role of multi-point measurements in turbulence investigations: the solar wind beyond single scale and beyond the Taylor HypothesisMar 16 2019This paper briefly reviews a number of fundamental measurements that need to be made in order to characterize turbulence in space plasmas such as the solar wind. It has long been known that many of these quantities require simultaneous multipoint measurements ... More
The STRIP instrument of the Large Scale Polarization Explorer: microwave eyes to map the Galactic polarized foregroundsDec 10 2018In this paper we discuss the latest developments of the STRIP instrument of the "Large Scale Polarization Explorer" (LSPE) experiment. LSPE is a novel project that combines ground-based (STRIP) and balloon-borne (SWIPE) polarization measurements of the ... More
A search for low-energy neutrinos correlated with gravitational wave events GW150914, GW151226 and GW170104 with the Borexino detectorJun 30 2017We present the results of a low-energy neutrino search using the Borexino detector in coincidence with the gravitational wave (GW) events GW150914, GW151226 and GW170104. We searched for correlated neutrino events with energies greater than 250 keV within ... More
First Simultaneous Precision Spectroscopy of $pp$, $^7$Be, and $pep$ Solar Neutrinos with Borexino Phase-IIJul 28 2017Dec 01 2017We present the first simultaneous measurement of the interaction rates of $pp$, $^7$Be, and $pep$ solar neutrinos performed with a global fit to the Borexino data in an extended energy range (0.19-2.93)$\,$MeV. This result was obtained by analyzing 1291.51$\,$days ... More
Inconsistence of super-luminal Cern-Opera neutrino speed with observed SN1987A burst and neutrino mixing for any imaginary neutrino massSep 25 2011Mar 05 2012We tried to fit in any way the recent Opera-Cern claims of a neutrino super-luminal speed with observed Supernova SN1987A neutrino burst and all (or most) neutrino flavor oscillation. We considered three main frame-works: (1) A tachyon imaginary neutrino ... More
Some surface subgroups survive surgeryApr 07 2001It is shown that with finitely many exceptions, the fundamental group obtained by Dehn surgery on a one cusped hyperbolic 3-manifold contains the fundamental group of a closed surface.
Neutrino oscillations along the Earth to probe flavor parameters: a NeuWorldJan 11 2013Mar 12 2013On 2010 MINOS experiment was showing an hint of possible different mass splitting and mixing angles for neutrinos and anti-neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector; last year 2012 a second result from MINOS showed ... More
Beaming Selection and SN-GRB-Jets EvolutionFeb 19 2009After a decade of Fireball reign there is a hope for thin collimated Jet to solve the Supernova-GRB mystery
Cen A persistence and Virgo absence versus updated maps to understand UHECR natureDec 31 2010Ultra High Cosmic Rays (UHECR) should be tracing their sources, making a new astronomy. Their events counting are finally growing, by Auger experiment, into cosmic sky. Their map should follow the mass distribution in a narrow cosmic volume (the GZK cut ... More
Deep Core muon neutrino rate and anisotropy by mixing and CPT violationDec 23 2010Neutrinos are allowed to mix and to oscillate among their flavor. Muon and tau in particular oscillate at largest values.Last Minos experiment claimed possible difference among their matter and anti-matter masses, leading to a first violation of the most ... More
Achievements and Mirages in Uhecr and Neutrino AstronomyMay 11 2009Photon Astronomy ruled the last four centuries while wider photon band ruled last radio-X-Gamma century of discovery. Present decade may see the rise and competition of UHECR and UHE Neutrino Astronomy. Tau Neutrino may win and be the first flavor revealed. ... More
An apparent GRBs evolution around us or a sampling of thin GRB beaming jets?Oct 13 2009Oct 14 2009The gamma ray burst apparent average isotropic power versus their red-shift of all known GRB (Sept.2009) is reported. It calls for an unrealistic Gamma Ray Burst Evolution around us or it just probe the need of a very thin gamma precession-jet model. ... More
Anisotropies of Cosmic Rays and Search for Intergalactic Cascades from the direction of the Highest Energetic Cosmic Ray Events with the HEGRA Scintillator ArraySep 07 1999Data taken with the HEGRA Scintillator Array have been used to search for spatial anisotropies in the arrival directions of cosmic rays above 20 TeV. In this paper results on the search for TeV gamma-ray emission from the Galactic plane and the Gould ... More
Perturbative BPS-algebras in superstring theoryFeb 27 1997This paper investigates the algebraic structure that exists on perturbative BPS-states in the superstring, compactified on the product of a circle and a Calabi-Yau fourfold. This structure was defined in a recent article by Harvey and Moore. It shown ... More
Solid State Quantum BitsMay 27 2005We present the solid-state quantum circuits that have been developed in order to implement quantum bits suitable for a quantum processor. These qubits are either based on the quantum state of a single particle (semiconductor qubits), or on the quantum ... More
Applying MVC and PAC patterns in mobile applicationsJan 20 2010Additional requirements are set for mobile applications in relation to applications for desktop computers. These requirements primarily concern the support to different platforms on which such applications are performed, as well as the requirement for ... More
Bound States and Superconductivity in Dense Fermi SystemsDec 02 2008A quantum field theoretical approach to the thermodynamics of dense Fermi systems is developed for the description of the formation and dissolution of quantum condensates and bound states in dependence of temperature and density. As a model system we ... More
Gravity as an effective theoryOct 21 2009Using as inspiration the well known chiral effective lagrangian describing the interactions of pions at low energies, in these lectures we review the quantization procedure of Einstein gravity in the spirit of effective field theories. As has been emphasized ... More
Superconductivity in the 2D Hubbard model: Electron doping is differentAug 04 2008A variational Monte Carlo calculation is used for studying the ground state of the two-dimensional Hubbard model, including hopping between both nearest and next-nearest neighbor sites. Superconductivity with d-wave symmetry is found to be restricted ... More
Classical Functional Bethe Ansatz for $SL(N)$: separation of variables for the magnetic chainMar 04 1994The Functional Bethe Ansatz (FBA) proposed by Sklyanin is a method which gives separation variables for systems for which an $R$-matrix is known. Previously the FBA was only known for $SL(2)$ and $SL(3)$ (and associated) $R$-matrices. In this paper I ... More
A new class of magnetic materials: Sr2FeMoO6 and related compoundsFeb 27 2001Ordered double perovskite oxides of the general formula, A2BB'O6, have been known for several decades to have interesting electronic and magnetic properties. However, a recent report of a spectacular negative magnetoresistance effect in a specific member ... More
Existence, multiplicity and stability of endemic states for an age-structured S-I epidemic modelJun 20 2008Feb 25 2010We study an S--I type epidemic model in an age-structured population, with mortality due to the disease. A threshold quantity is found that controls the stability of the disease-free equilibrium and guarantees the existence of an endemic equilibrium. ... More
A locally symmetric Kaehler Einstein structure on the cotangent bundle of a space formAug 25 2003We obtain a locally symmetric Kaehler Einstein structure on the cotangent bundle of a Riemannian manifold of negative constant sectional curvature. Similar results are obtained on a tube around zero section in the cotangent bundle, in the case of a Riemannian ... More
Deformation effects on the coexistence between neutron-proton and particle like pairing in N=Z medium mass nucleiNov 07 2014A model combining self-consistent mean-field and shell-model techniques is used to study the competition between particle like and proton-neutron pairing correlations in fp-shell even-even self-conjugate nuclei. Results obtained using constant two-body ... More
The accretion-diffusion scenario for metals in cool white dwarfsMar 08 2006We calculated diffusion timescales for Ca, Mg, Fe in hydrogen atmosphere white dwarfs with temperatures between 5000 and 25000 K. With these timescales we determined accretion rates for a sample of 38 DAZ white dwarfs from the recent studies of Zuckerman ... More
The elliptic genus of Calabi-Yau 3- and 4-folds, product formulae and generalized Kac-Moody algebrasJul 03 1996In this paper the elliptic genus for a general Calabi-Yau fourfold is derived. The recent work of Kawai calculating N=2 heterotic string one-loop threshold corrections with a Wilson line turned on is extended to a similar computation where K3 is replaced ... More
Spherical varieties and Langlands dualityNov 10 2006Aug 07 2007Let G be a connected reductive complex algebraic group. This paper is devoted to the space Z of meromorphic quasimaps from a curve into an affine spherical G-variety X. The space Z may be thought of as an algebraic model for the loop space of X. In this ... More
Chemical evolution of turbulent protoplanetary disks and the Solar nebulaApr 21 2011Aug 23 2011This is the second paper in a series where we study the influence of transport processes on the chemical evolution of protoplanetary disks. Our analysis is based on a flared alpha-model of the DM Tau system, coupled to a large gas-grain chemical network. ... More
A locally symmetric Kaehler Einstein structure on a tube in the nonzero cotangent bundle of a space formAug 29 2003We obtain a locally symmetric Kaehler Einstein structure on a tube in the nonzero cotangent bundle of a Riemannian manifold of positive constant sectional curvature. The obtained Kaehler Einstein structure cannot have constant holomorphic sectional curvature. ... More
Uniform Kazhdan groupsJun 01 2006We construct first examples of infinite groups having property (T) whose Kazhdan constants admit a lower bound independent of the choice of a finite generating set.
Intrinsic Properties of the <z>=2.7 Lyman Alpha Forest from Keck Spectra of QSO HS 1946+7658Jan 27 1997Feb 20 1997We present the highest quality Lyman Alpha forest spectra published to date, from the QSO HS 1946+7658. The distribution of H I column densities is a power law of slope -1.5 from Log N = 12.1 - 14. This power law can extend to N = 0, because lines weaker ... More
Possible flakes of molecular hydrogen in the early UniverseNov 18 2002The thermochemistry of H2 and HD in non-collapsed, non-reionized primordial gas up to the end of the dark age is investigated with recent radiation-matter and chemical reaction rates taking into account the efficient coolant HD, and the possibility of ... More
The category of singularities as a crystal and global Springer fibersDec 14 2014May 12 2015We prove the "Gluing Conjecture" on the spectral side of the categorical geometric Langlands correspondence. The key tool is the structure of crystal on the category of singularities, which allows to reduce the conjecture to the question of homological ... More
The spin-1 ladder : A bosonization studyAug 16 1999We construct a field-theoretic description of two coupled spin-1 Heisenberg chains, starting with the known representation of a single spin-1 chain in terms of Majorana fermions (or Ising models). After reexamining the bosonization rules for two Ising ... More
Ginzburg-Landau equations for superconducting quark matter in neutron starsJun 19 2000May 18 2002We investigate magnetic properties of color superconducting quark matter within a Ginzburg-Landau approach. The simultaneous coupling of the quark fields to gluonic and electromagnetic gauge fields leads to rotated electromagnetism with a massive (Higgsed) ... More
13CO(1-0) and 12CO(2-1) in the center of the barred galaxy NGC 1530Apr 26 1999We present 13CO(1-0) and 12CO(2-1) aperture synthesis maps of the barred spiral galaxy NGC1530. The angular resolutions are respectively 3''.1 and 1''.6. Both transitions show features similar to the 12CO(1-0) map, with a nuclear feature (a ring or unresolved ... More
Production of complex particles in low energy spallation and in fragmentation reactions by in-medium random clusterizationMay 18 2005Rules for in-medium complex particle production in nuclear reactions are proposed. These rules have been implemented in two models to simulate nucleon-nucleus and nucleus-nucleus reactions around the Fermi energy. Our work emphasizes the effect of randomness ... More
Quantitative determination of the level of cooperation in the presence of punishment in three public good experimentsOct 25 2006Nov 21 2007Strong reciprocity is a fundamental human characteristic associated with our extraordinary sociality and cooperation. Laboratory experiments on social dilemma games and many field studies have quantified well-defined levels of cooperation and propensity ... More
Representations of algebraic groups over a 2-dimensional local fieldFeb 14 2003Jun 14 2004We introduce a categorical framework for the study of representations of $G_F$, where $G$ is a reductive group, and $\bF$ is a 2-dimensional local field, i.e. $F=K((t))$, where $K$ is a local field. Our main result says that the space of functions on ... More
Hecke operators on quasimaps into horospherical varietiesNov 11 2004Nov 10 2006Let $G$ be a connected reductive complex algebraic group. This paper is part of a project devoted to the space $Z$ of meromorphic quasimaps from a curve into an affine spherical $G$-variety $X$. The space $Z$ may be thought of as an algebraic model for ... More
Controlled dynamics of qubits in the presence of decoherenceJun 19 2007An exactly solvable model for the decoherence of one and two-qubit states interacting with a spin-bath, in the presence of a time-dependent magnetic field is studied. The magnetic field is static along $\hat{z}$ direction and oscillatory in the transverse ... More
Morphological Annotations for Groups in the FIRST DatabaseApr 19 2011The morphology of selected groups of sources in the FIRST (Faint Images of the Radio Sky at Twenty Centimeters) survey and catalog is examined. Sources in the FIRST catalog (April 2003 release, 811117 entries) were sorted into singles, doubles, triples ... More
Superconductivity and antiferromagnetism in the two-dimensional Hubbard model: a variational studyAug 21 2007A variational ground state of the repulsive Hubbard model on a square lattice is investigated numerically for an intermediate coupling strength (U = 8t) and for moderate sizes (from 6 x 6 to 10 x 10). Our ansatz is clearly superior to other widely used ... More
Relaxation measurements in the regime of the second magnetization peak in Nb filmsNov 05 2004We report on magnetic measurements as a function of field, temperature and time (relaxation) in superconducting Nb films of critical temperature Tc = 9.25 K. The magnetic measurements as a function of field exhibited a second magnetization peak (SMP) ... More
Microscopic description of pair transfer between two superfluid systems (II): a quantum mixing of Time-Dependent Hartree-Fock Bogolyubov trajectoriesFeb 18 2019While superfluidity is accurately grasped with a state that explicitly breaks the particle number symmetry, a precise description of phenomena like the particle transfer during heavy-ion reactions can only be achieved by considering systems with good ... More
Hadronic resonances, strange and multi-strange particle production in Xe-Xe and Pb-Pb collisions with ALICE at the LHCJul 23 2018We present measurements of hadronic resonance, strange and multi-strange particle production in collisions of Xe-Xe and Pb-Pb at the center-of-mass energies of $\sqrt{s_{NN}}=5.44$ and $5.02$ TeV, respectively, by the ALICE collaboration at the LHC. Particle ... More
A class of locally symmetric Kaehler Einstein structures on the nonzero cotangent bundle of a space formJul 21 2004We obtain a class of locally symetric Kaehler Einstein structures on the nonzero cotangent bundle of a Riemannian manifold of positive constant sectional curvature. The obtained class of Kaehler Einstein structures depends on one essential parameter and ... More
A Kaehler Einstein structure on the nonzero cotangent bundle of a space formMay 07 2004We obtain a Kaehler Einstein structure on the nonzero cotangent bundle of a Riemannian manifold of positive constant sectional curvature. The obtained Kaehler Einstein structure cannot have constant holomorphic sectional curvature and is not locally symmetric. ... More