Results for "G. Catelani"

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Interaction corrections: temperature and parallel field dependencies of the Lorentz number in two-dimensional disordered metalsOct 12 2006Jan 31 2007The electron-electron interaction corrections to the transport coefficients are calculated for a two-dimensional disordered metal in a parallel magnetic field via the quantum kinetic equation approach. For the thermal transport, three regimes (diffusive, ... More
Parity switching and decoherence by quasiparticles in single-junction transmonsJan 22 2014The transmon superconducting qubit is being intensely investigated as a promising approach for the physical implementation of quantum information processing, and high quality factors of order $10^6$ have been achieved both in two- and three-dimensional ... More
Tunneling anomaly of superconducting films in strong magnetic fieldsJan 17 2006We consider the tunneling Density of States (DoS) of superconducting films driven to the paramagnetic phase by the Zeeman splitting. We show that there is minimum in the DoS whose position depends on the orientation of the applied field. This dependence, ... More
Collective modes in the fluxonium qubitJun 29 2015Superconducting qubit designs vary in complexity from single- and few-junction systems, such as the transmon and flux qubits, to the many-junction fluxonium. Here we consider the question of wether the many degrees of freedom in the fluxonium circuit ... More
On the sqrt{2} puzzle in AdS_2/CFT_1Sep 25 2000Nov 07 2000In this letter we analyze the Hamiltonian formulation of the Jackiw-Teitelboim model of 2D gravity and calculate the central charge associated with the asymptotic symmetries, taking care of boundary terms. For black hole solutions, we show that there ... More
Effect of Coulomb interaction on current noise in open quantum dotsNov 13 2007We analyze the effect of Coulomb interaction on the noise of electric current through an open quantum dot. We demonstrate that the ensemble average value of the noise power acquires an interaction correction even for a dot coupled to the leads by reflectionless ... More
Temperature dependence of the superheating field for superconductors in the high-k London limitOct 26 2008Dec 08 2008We study the metastability of the superheated Meissner state in type II superconductors with k >> 1 beyond Ginzburg-Landau theory, which is applicable only in the vicinity of the critical temperature. Within Eilenberger's semiclassical approximation, ... More
Phase diagram, extended domain walls, and soft collective modes in a three component fermionic superfluidMay 23 2008Oct 03 2008We study the phase diagram of a three-component Fermi gas with weak attractive interactions, which shows three superfluid and one normal phases. At weak symmetry breaking between the components the existence of domain walls interpolating between two superfluids ... More
Interaction corrections to the thermal transport coefficients in disordered metals: quantum kinetic equation approachMay 14 2004We consider the singular electron-electron interaction corrections to the transport coefficients in disordered metals to test the validity of the Wiedemann-Franz law. We develop a local, quantum kinetic equation approach in which the charge and energy ... More
Coreless vorticity in multicomponent Bose and Fermi superfluidsSep 21 2009We consider quantized vortices in two-component Bose-Einstein condensates and three-component Fermi gases with attractive interactions. In these systems, the vortex core can be either empty (normal in the fermion case) or filled with another superfluid. ... More
Spin Related Effects in Transport Properties of "Open" Quantum DotsSep 14 2005We study the interaction corrections to the transport coefficients in open quantum dots (i.e. dots connected to leads of large conductance $G \gg e^2/\pi\hbar$), via a quantum kinetic equation approach. The effects of all the channels of the universal ... More
Action, Hamiltonian and CFT for 2D black holesAug 07 2000Aug 08 2000The boundary terms in the Hamiltonian, in the presence of horizons, are carefully analyzed in a simple 2D theory admitting AdS black holes. The agreement between the euclidean approach and Cardy's formula is obtained modulo certain assumptions on the ... More
Quantum-fluctuation effects in transport properties of superconductors above the paramagnetic limitFeb 23 2012We study the transport in ultrathin disordered film near the quantum critical point induced by the Zeeman field. We calculate corrections to the normal state conductivity due to quantum pairing fluctuations. The fluctuation-induced transport is mediated ... More
Dissipation in a superconducting artificial atom due to a single non-equilibrium quasiparticleSep 01 2017We study a superconducting artificial atom which is represented by a single Josephson junction or a Josephson junction chain, capacitively coupled to a coherently driven transmission line, and which contains exactly one residual quasiparticle (or up to ... More
Effect of Quasiparticles Injection on the AC Response of a SuperconductorJul 08 2010We calculate the AC linear response of a superconductor in a nonequilibrium electronic state. The nonequilibrium state is produced by injecting quasiparticles into the superconductor from normal leads through asymmetric tunnel contacts. The dissipative ... More
Fermi-liquid effects in the gapless state of marginally thin superconducting filmsSep 24 2008We present low temperature tunneling density-of-states measurements in Al films in high parallel magnetic fields. The thickness range of the films, t=6-9 nm, was chosen so that the orbital and Zeeman contributions to their parallel critical fields were ... More
Orbital Response of Evanescent Cooper Pairs in Paramagnetically Limited Al FilmsJan 17 2006We report a detailed study of the pairing resonance via tunneling density of states in ultra-thin superconducting Al films in supercritical magnetic fields. Particular emphasis is placed on effects of the perpendicular component of the magnetic field ... More
Density of States, Entropy, and the Superconducting Pomeranchuk Effect in Pauli-Limited Al FilmsSep 09 2006We present low temperature tunneling density of states measurements of Pauli-limited Al films in which the Zeeman and orbital contributions to the critical field are comparable. We show that films in the thickness range of 6-7 nm exhibit a reentrant parallel ... More
Spin-Resolved Tunneling Studies of the Exchange Field in EuS/Al BilayersMay 18 2011We use spin-resolved electron tunneling to study the exchange field in the Al component of EuS/Al bilayers, in both the superconducting and normal-state phases of the Al. Contrary to expectation, we show that the exchange field, Hex, is a non-linear function ... More
Saturation of the Anomalous Hall Effect in Critically Disordered Ultra-thin CNi3 FilmsJan 31 2010We demonstrate that a distinct high-disorder anomalous Hall effect phase emerges at the correlated insulator threshold of ultra-thin, amorphous, ferromagnetic CNi3 films. In the weak localization regime, where the sheet conductance G >> e^2/h, the anomalous ... More
Measurement of Conduction Electron Polarization Via the Pairing ResonanceJul 10 2009We show that the pairing resonance in the Pauli-limited normal state of ultra-thin superconducting Al films provides a spin-resolved probe of conduction electron polarization in thin magnetic films. A superconductor-insulator-ferromagnet tunneling junction ... More
Atomic-scale tailoring of spin susceptibility via non-magnetic spin-orbit impuritiesNov 13 2018Following the discovery of topological insulators, there has been a renewed interest in superconducting systems that have strong spin-orbit (SO) coupling. Here we address the fundamental question of how the spin properties of a otherwise spin-singlet ... More
Photon-assisted charge-parity jumps in a superconducting qubitApr 12 2019We evaluate the rates of energy and phase relaxation of a superconducting qubit caused by stray photons with energy exceeding the threshold for breaking a Cooper pair. All channels of relaxation within this mechanism are associated with the change in ... More
Pairing resonance as a normal-state spin probe in ultra-thin Al filmsMay 14 2009Aug 24 2009We present a quantitative analysis of the low-temperature, high parallel field pairing resonance in ultra-thin superconducting Al films with dimensionless conductance g>>1. In this regime we derive an analytical expression for the tunneling density-of-states ... More
Decoherence of superconducting qubits caused by quasiparticle tunnelingJul 30 2012In superconducting qubits, the interaction of the qubit degree of freedom with quasiparticles defines a fundamental limitation for the qubit coherence. We develop a theory of the pure dephasing rate \Gamma_{\phi} caused by quasiparticles tunneling through ... More
Relaxation and frequency shifts induced by quasiparticles in superconducting qubitsJun 04 2011As low-loss non-linear elements, Josephson junctions are the building blocks of superconducting qubits. The interaction of the qubit degree of freedom with the quasiparticles tunneling through the junction represent an intrinsic relaxation mechanism. ... More
Quasiparticle relaxation of superconducting qubits in the presence of fluxJan 07 2011Jan 21 2011Quasiparticle tunneling across a Josephson junction sets a limit for the lifetime of a superconducting qubit state. We develop a general theory of the corresponding decay rate in a qubit controlled by a magnetic flux. The flux affects quasiparticles tunneling ... More
Mystery of Excess Low Energy States in a Disordered Superconductor in a Zeeman FieldFeb 18 2011Aug 21 2011Tunneling density of states measurements of disordered superconducting (SC) Al films in high Zeeman fields reveal a significant population of subgap states which cannot be explained by standard BCS theory. We provide a natural explanation of these excess ... More
Normal-metal quasiparticle traps for superconducting qubitsJun 14 2016The presence of quasiparticles in superconducting qubits emerges as an intrinsic constraint on their coherence. While it is difficult to prevent the generation of quasiparticles, keeping them away from active elements of the qubit provides a viable way ... More
Photon Shot Noise Dephasing in the Strong-Dispersive Limit of Circuit QEDJun 06 2012We study the photon shot noise dephasing of a superconducting transmon qubit in the strong-dispersive limit, due to the coupling of the qubit to its readout cavity. As each random arrival or departure of a photon is expected to completely dephase the ... More
Biotransformation and biological impact of graphene and graphene oxide during simulated oral ingestionMar 21 2019Graphene is an innovative nanomaterial, made of two-dimensional honeycomb-like carbon lattice, with potential in many different applications. Studying the behaviour of graphene-related materials (GRMs) in biological systems is, therefore, crucial to assess ... More
Exchange-interaction of two spin qubits mediated by a superconductorSep 21 2015Entangling two quantum bits by letting them interact is the crucial requirements for building a quantum processor. For qubits based on the spin of the electron, these two-qubit gates are typically performed by exchange interaction of the electrons captured ... More
Observation of high coherence in Josephson junction qubits measured in a three-dimensional circuit QED architectureMay 23 2011Nov 02 2011Superconducting quantum circuits based on Josephson junctions have made rapid progress in demonstrating quantum behavior and scalability. However, the future prospects ultimately depend upon the intrinsic coherence of Josephson junctions, and whether ... More
Reaching 10 ms single photon lifetimes for superconducting aluminum cavitiesFeb 18 2013May 22 2013Three-dimensional microwave cavities have recently been combined with superconducting qubits in the circuit quantum electrodynamics (cQED) architecture. These cavities should have less sensitivity to dielectric and conductor losses at surfaces and interfaces, ... More
Measurements of Quasiparticle Tunneling Dynamics in a Bandgap-Engineered Transmon QubitDec 12 2011We have engineered the bandgap profile of transmon qubits by combining oxygen-doped Al for tunnel junction electrodes and clean Al as quasiparticle traps to investigate energy relaxation due to quasiparticle tunneling. The relaxation time $T_1$ of the ... More
Superheating field of superconductors within Ginzburg-Landau theoryAug 26 2010We study the superheating field of a bulk superconductor within Ginzburg-Landau theory, which is valid near the critical temperature. We calculate, as functions of the Ginzburg-Landau parameter $\kappa$, the superheating field $\Hsh$ and the critical ... More
Zeeman-limited Superconductivity in Crystalline Al FilmsMar 10 2017We report the evolution of the Zeeman-mediated superconducting phase diagram (PD) in ultra-thin crystalline Al films. Parallel critical field measurements, down to 50 mK, were made across the superconducting tricritical point of films ranging in thickness ... More
Shielding superconductors with thin filmsJun 28 2015Determining the optimal arrangement of superconducting layers to withstand large amplitude AC magnetic fields is important for certain applications such as superconducting radiofrequency cavities. In this paper, we evaluate the shielding potential of ... More
Response to comment on theoretical RF field limits of multilayer coating structures of superconducting resonator cavitiesOct 16 2013A comment to the authors' SRF Conference pre-print [1] was submitted by A. Gurevich to the arXiv [2]. In this response, we show that the arguments used in the comment are not valid. [1] arXiv:1309.3239 [2] arXiv:1309.5626
Flux Qubits with Long Coherence Times for Hybrid Quantum CircuitsMar 16 2014Jul 04 2014We present measurements of superconducting flux qubits embedded in a three dimensional copper cavity. The qubits are fabricated on a sapphire substrate and are measured by coupling them inductively to an on-chip superconducting resonator located in the ... More
Theoretical estimates of maximum fields in superconducting resonant radio frequency cavities: Stability theory, disorder, and laminatesJul 31 2016Oct 26 2016Theoretical limits to the performance of superconductors in high magnetic fields parallel to their surfaces are of key relevance to current and future accelerating cavities, especially those made of new higher-Tc materials such as Nb$_3$Sn, NbN, and MgB$_2$. ... More
Theoretical Field Limits for Multi-Layer SuperconductorsSep 12 2013Sep 16 2013The SIS structure---a thin superconducting film on a bulk superconductor separated by a thin insulating film---was propsed as a method to protect alternative SRF materials from flux penetration by enhancing the first critical field $B_{c1}$. In this work, ... More
Theoretical estimates of maximum fields in superconducting resonant radio frequency cavities: Stability theory, disorder, and laminatesJul 31 2016Aug 03 2016We review our work on theoretical limits to the performance of superconductors in high magnetic fields parallel to their surfaces. These limits are of key relevance to current and future accelerating cavities, especially those made of new higher-$T_c$ ... More
Tunable superconducting nanoinductorsJul 23 2010Sep 27 2010We characterize inductors fabricated from ultra-thin, approximately 100 nm wide strips of niobium (Nb) and niobium nitride (NbN). These nanowires have a large kinetic inductance in the superconducting state. The kinetic inductance scales linearly with ... More
Quasiparticle dynamics in granular aluminum close to the superconductor to insulator transitionFeb 06 2018Feb 07 2018Superconducting high kinetic inductance elements constitute a valuable resource for quantum circuit design and millimeter-wave detection. Granular aluminum (GrAl) in the superconducting regime is a particularly interesting material since it has already ... More
Hierarchical microplates as drug depots with controlled geometry, rigidity and therapeutic efficacyMar 08 2019A variety of microparticles have been proposed for the sustained and localized delivery of drugs whit the objective of increasing therapeutic indexes by circumventing filtering organs and biological barriers. Yet, the geometrical, mechanical and therapeutic ... More
Non-Poissonian Quantum Jumps of a Fluxonium Qubit due to Quasiparticle ExcitationsJun 06 2014Dec 09 2014As the energy relaxation time of superconducting qubits steadily improves, non-equilibrium quasiparticle excitations above the superconducting gap emerge as an increasingly relevant limit for qubit coherence. We measure fluctuations in the number of quasiparticle ... More
Interplay between kinetic inductance, non-linearity and quasiparticle dynamics in granular aluminum MKIDsOct 29 2018Nov 10 2018Microwave kinetic inductance detectors (MKIDs) are thin film, cryogenic, superconducting resonators. Incident Cooper pair-breaking radiation increases their kinetic inductance, thereby measurably lowering their resonant frequency. For a given resonant ... More
Measurement and Control of Quasiparticle Dynamics in a Superconducting QubitJun 27 2014Oct 24 2014Superconducting circuits have attracted growing interest in recent years as a promising candidate for fault-tolerant quantum information processing. Extensive efforts have always been taken to completely shield these circuits from external magnetic field ... More
Self-induced decoherence in dense neutrino gasesJan 22 2007Dense neutrino gases exhibit collective oscillations where "self-maintained coherence" is a characteristic feature, i.e., neutrinos of different energies oscillate with the same frequency. In a non-isotropic gas, however, the flux term of the neutrino-neutrino ... More
Spin-Rotation Coupling in Muon g-2 ExperimentsJun 21 2001Spin-rotation coupling, or Mashhoon effect, is a phenomenon associated with rotating observers. We show that the effect exists and plays a fundamental role in the determination of the anomalous magnetic moment of the muon.
Baryogenesis in $f(R)$-Theories of GravityOct 12 2006$f(R)$-theories of gravity are reviewed in the context of the so called gravitational baryogenesis. The latter is a mechanism for generating the baryon asymmetry in the Universe, and relies on the coupling between the Ricci scalar curvature $R$ and the ... More
Comment on "Dynamics of Weak First Order Phase Transitions"Nov 08 1995We comment on an earlier paper of M. Gleiser, regarding mechanisms of first-order phase transitions.
A multi-frequency study of the spectral index distribution in the SNR CTB 80Jul 29 2005We have conducted a study at radio wavelengths of the spectral behaviour of the supernova remnant (SNR) CTB 80. Based on an homogenised data set of integrated flux densities, we calculated for the whole SNR a radio index -0.36 +/- 0.02. The shape of the ... More
The Sato Grassmannian and the CH hierarchyFeb 29 2008We discuss how the Camassa-Holm hierarchy can be framed within the geometry of the Sato Grassmannian.
Simple Fluids with Complex Phase BehaviorMay 12 2000We find that a system of particles interacting through a simple isotropic potential with a softened core is able to exhibit a rich phase behavior including: a liquid-liquid phase transition in the supercooled phase, as has been suggested for water; a ... More
Local Magnetic Turbulence and TeV-PeV Cosmic Ray AnisotropiesNov 10 2011Aug 22 2012In the energy range from ~ 10^12 eV to ~ 10^15 eV, the Galactic cosmic ray flux has anisotropies both on large scales, with an amplitude of the order of 0.1%, and on scales between ~ 10 and ~ 30 degrees, with amplitudes smaller by a factor of a few. With ... More
Stationary Axisymmetric Solutions and their Energy Contents in Teleparallel Equivalent of Einstein TheoryMar 03 2015We apply the energy-momentum tensor which is coordinate independent to calculate the energy content of the axisymmetric solutions. Our results are compared with what have been obtained before within the framework of Einstein general relativity and M{\o}ler's ... More
Schwarzschild solution in extended teleparallel gravityJan 05 2015Tetrad field, with two unknown functions of radial coordinate and an angle $\Phi$ which is the polar angle $\phi$ times a function of the redial coordinate, is applied to the field equation of modified theory of gravity. Exact vacuum solution is derived ... More
Regularization of Kerr-NUT spacetimes and their thermodynamical quantitiesApr 27 2015In the context of the teleparallel equivalent of general relativity (TEGR) theory, continues calculations of the total energy and momentum for Kerr-NUT spacetimes using three different methods, the gravitational energy-momentum, the Riemannian connection ... More
Sulfur-bearing species in molecular cloudsOct 30 2014We study several molecules that could help in the solution of the missing sulfur problem in dense clouds and circumstellar regions, as well as in the clarification of the sulfur chemistry in comets. These sulfur molecules are: the trimer (CH2S)3 and the ... More
Neutrino Masses in Astrophysics and CosmologyDec 08 1997Cosmology yields the most restrictive limits on neutrino masses and conversely, massive neutrinos would contribute to the cosmic dark-matter density and would play an important role for the formation of structure in the universe. Neutrino oscillations ... More
Quick View on Jet Tomography at RHIC EnergiesDec 31 2003A strong suppression of Pi production in Au+Au collision was discovered at RHIC energies in the high-p_T region. The lack of this suppression in d+Au collision proved, this effect can be connected to final state effects, namely medium induced jet energy ... More
GRB 060218 and the outliers with respect to the Ep-Eiso correlationJan 31 2007GRB 031203 and GRB 980425 are the two outliers with respect to the Ep-Eiso correlation of long GRBs. Recently Swift discovered a nearby extremely long GRB 060218 associated with a SN event. The spectral properties of this bursts are striking: on the one ... More
Prediction of the Proton-to-Total Turbulent Heating in the Solar WindJun 21 2011This paper employs a recent turbulent heating prescription to predict the ratio of proton-to-total heating due to the kinetic dissipation of Alfvenic turbulence as a function of heliocentric distance. Comparing to a recent empirical estimate for this ... More
A Dynamical Model of Plasma Turbulence in the Solar WindFeb 13 2015A dynamical approach, rather than the usual statistical approach, is taken to explore the physical mechanisms underlying the nonlinear transfer of energy, the damping of the turbulent fluctuations, and the development of coherent structures in kinetic ... More
Thermal stability of self-gravitating, optically thin accretion disksFeb 09 2001In the dynamics of accretion disks, the presence of collective effects associated with the self-gravity of the disk is expected to affect not only the momentum transport, but also the relevant energy balance equations, which could differ substantially ... More
The Correlated Lloyd model: exact solutionFeb 24 2014Exactly solvable model of disordered system representing the generalized Lloyd model with correlated random potential is described. It is shown, that for the model under consideration, the averaged Green's function does not depend on random potential ... More
Exactly solvable spin dynamics of an electron coupled to large number of nuclei and the electron-nuclear spin echo in a quantum dotApr 03 2007Apr 10 2007The model considered in the paper is used nowadays to describe spin dynamics of quantum dots after optical excitation. Based on the exact diagonalization of a model Hamiltonian, we solve the problems of the electron spin polarization decay and magnetic ... More
Noise spectroscopy of optical microcavityMar 21 2012The intensity noise spectrum of the light passed through an optical microcavity is calculated with allowance for thermal fluctuations of its thickness. The spectrum thus obtained reveals a peak at the frequency of acoustic mode localized inside the microcavity ... More
PyECLOUD and build-up simulations at CERNSep 26 2013PyECLOUD is a newly developed code for the simulation of the electron cloud (EC) build-up in particle accelerators. Almost entirely written in Python, it is mostly based on the physical models already used in the ECLOUD code but, thanks to the implementation ... More
Cocycle conjugacy of quasifree endomorphisms semigroups on the CAR algebraOct 18 2000Oct 20 2000W. Arveson has described a cocycle conjugacy class $U(\alpha)$ of $E_0$-semigroup $\alpha$ on B(H) which is a factor of type $\rm I$. Under some conditions on $\alpha$, there is a $E_0$-semigroup $\beta \in U(\alpha)$ being a flow of shifts in the sence ... More
NANOTCAD2D: Two-dimensional code for the simulation of nanoelectronic devices and structuresDec 22 2003In this paper we present NANOTCAD2D, a code for the simulation of the electrical properties of semiconductor-based nanoelectronic devices and structures in two-dimensional domains. Such code is based on the solution of the Poisson/Schr\"odinger equation ... More
Metastable states in the planar 2d XY model and dissipation in superfluid flowJun 11 2004We use the Metropolis algorithm to study the stability of superfluid flow in a model system, namely the two-dimensional planar XY model. Flow properties are examined by studying the behaviour of the system in meta-stable ``twisted'' states. We demonstrate ... More
Renormalization group approach to the one-dimensional 1/4-filled Hubbard model with alternating on-site interactionsAug 30 1999The one-dimensional Hubbard model with different on-site interactions is investigated by renormalization group technique. In the case of a 1/4-filled band the dynamical nonequivalence of sites leads to the appearance of Umklapp processes in the system ... More
EChO spectra and stellar activity II. The case of dM starsJan 27 2014EChO is a dedicated mission to investigate exoplanetary atmospheres. When extracting the planetary signal, one has to take care of the variability of the hosting star, which introduces spectral distortion that can be mistaken as planetary signal. Magnetic ... More
Anisotropic illumination of AGN's accretion disk by a non thermal source : I General theory and application to the Newtonian geometryMay 29 1997We present a model of accretion disk where the disk luminosity is entirely due to the reprocessing of hard radiation impinging on the disk. The hard radiation itself is emitted by a hot point source above the disk, that could be physically realized by ... More
FRW in quadratic form of $f(T)$ gravitational theoriesJun 26 2015We derive asymptote solution of a homogeneous and isotropic universe governed by the quadratic form of the field equation of $f(T)$ gravity. We explain how the higher order of the torsion can provide an origin for late accelerated phase of the universe ... More
The Phenomenologically symmetric geometry of two sets of rank (3,2)Jun 09 2014A geometry of two sets (GTS) is given on manifolds $\mathfrak{M}$ and $\mathfrak{N}$ by a metric (two-point) function $f:\mathfrak{M\times N}\to R$. Its phenomenological symmetry (PS) means that for some numbers of points from each manifold all the reciprocal ... More
Z Flux-Line Lattices and Self-Dual Equations in the Standard ModelMar 22 1994We derive gauge covariant self-dual equations for the $SU(2) \times U(1)_Y$ theory of electro-weak interactions and show that they admit solutions describing a periodic lattice of Z-strings.} \newpage
Vortex Solutions in Two-Higgs-Doublet SystemsJan 24 1994We analyze the existence of string-like defects in a two-Higgs-doublet system having $SU(2) \times U(1)_Y \times U(1)_{Y^{\prime}}$ as gauge group. We are able to show that, when certain relations among the parameters hold, these configurations satisfy ... More
Determination of the orbit spaces of non-coregular compact linear groups with one relation among the basic polynomial invariants in the $\hat P$-matrix approachAug 02 2000Invariant functions under the transformations of a compact linear group $G$ acting in $\real^n$ can be expressed in terms of functions defined in the orbit space of $G$. We develop a method to determine the isotropy classes of the orbit spaces of all ... More
Split dimensional regularization for the Coulomb gauge at two loopsNov 25 1999Nov 29 1999We evaluate the coefficients of the leading poles of the complete two-loop quark self-energy \Sigma(p) in the Coulomb gauge. Working in the framework of split dimensional regularization, with complex regulating parameters \sigma and n/2-\sigma for the ... More
Application of stochastic resonance in gravitational-wave interferometerJan 30 2006We investigate novel approach, which improves the sensitivity of gravitational wave (GW) interferometer due to stochastic resonance (SR) phenomenon, performing in additional nonlinear cavity (NC). The NC is installed in the output of interferometer before ... More
Advanced configuration of gravitational-wave interferometer on the base of "sensitive mode" in "white-light cavity"Nov 07 2002A novel conception of "sensitive mode" (SM) is proposed to apply in gravitational-wave advanced interferometer configuration. The SM is resonant oscillation of electromagnetic field in "white-light cavity", where the resonance line is broadened without ... More
The Loop-Tree Duality: Progress ReportSep 08 2017We review the recent developments of the Loop-Tree Duality method, focussing our discussion on the first numerical implementation and its use in the direct numerical computation of multi-leg Feynman integrals. Non-trivial examples are presented.
Exact Gravitational Gauge Structures and the Dirac EquationApr 27 1998Exact gauge structures arise in the evolution of spin-1/2 particles in conformally flat space-times. The corresponding Berry potentials can be Abelian or non-Abelian depending on the mass degeneracy of the system considered. Examples include de Sitter ... More
RSOS revisitedMar 08 2002We investigate the issues of unitarity and reality of the spectrum for the imaginary coupled affine Toda field theories based on a_1(1) and a_2(2) and the perturbed minimal models that arise from their various RSOS restrictions. We show that while all ... More
Non-integrable aspects of the multi-frequency Sine-Gordon modelSep 03 1997We consider the two-dimensional quantum field theory of a scalar field self-interacting via two periodic terms of frequencies $\alpha$ and $\beta$. Looking at the theory as a perturbed Sine-Gordon model, we use Form Factor Perturbation Theory to analyse ... More
Symplectic Structures and Quantum MechanicsMay 28 1996Canonical coordinates for the Schr\"odinger equation are introduced, making more transparent its Hamiltonian structure. It is shown that the Schr\"odinger equation, considered as a classical field theory, shares with Liouville completely integrable field ... More
Regularization of $f(T)$ gravity theories and local Lorentz transformationMar 27 2014Jul 18 2015We regularized the field equations of $f(T)$ gravity theories such that the effect of Local Lorentz Transformation (LLT), in the case of spherical symmetry, is removed. A "general tetrad field", with an arbitrary function of radial coordinate preserving ... More
Mu- and Tau-Neutrino Spectra Formation in SupernovaeMay 15 2001Jul 12 2001The mu- and tau-neutrinos emitted from a proto-neutron star are produced by nucleonic bremsstrahlung N + N -> N + N + nu + nu-bar and pair annihilation e^+ + e^- -> nu + nu-bar, reactions which freeze out at the "energy sphere." Before escaping from there ... More
Introduction to the Theory of Stellar EvolutionJun 13 2014In this chapter we briefly review the basics of the theory of stellar evolution.
Anisotropic inverse Compton scattering in radio galaxies and particle energy distributionOct 31 2000In this talk we briefly review the inverse Compton (IC) scattering of nuclear photons in the lobes of radio galaxies and quasars. We concentrate on the possibility to test this model with the Chandra observatory and to constrain the electron energy distribution ... More
The present and the future of cosmology with Gamma Ray BurstsFeb 22 2006Gamma Ray Bursts are among the most powerful astrophysical sources and they release up to 1.e54 erg, if isotropic, in less than few hundred seconds. Their detection in the hard X/gamma ray band (at energies >10 keV) and out to very high redshift (z~6.3) ... More
The narrow peak on the frequency dependance of the susceptibility of the harmonical oscillator in contact with thermostat with bosonic excitations. Exactly-solvable modelNov 22 2001The relaxation of the harmonical oscillator, being in contact with the thermostat whose excitations can be treated as bosons is studied. An exact temporary behavior of the inverse oscillator's temperature is obtained. In low interaction limit the temperature ... More
Spectrum and eigen functions of the operator $H_U f(x)\equiv f(U-1/x)/x^2$ and strange attractor's density for the mapping $x_{n+1}=1/(U-x_n)$Mar 13 2008We solve exactly the spectral problem for the non-Hermitian operator $H_U f(x)\equiv f(U-1/x)/x^2$. Despite the absence of orthogonality, the eigen functions of this operator allow one to construct in a simple way the expansion of an arbitrary function ... More
The limiting nuclear polarization in a quantum dot under optical electron-spin orientation and applicability of the box-model of the electron-nuclear dynamicsJan 09 2008For the model Hamiltonian describing the electron-nuclear dynamics of a quantum dot, we obtained an exact expression for the limiting nuclear polarization as a function of the number of groups of equivalent nuclei. It is shown that the refinement of the ... More
To the possibility of the "slow light" in the waveguidesDec 22 2005The atoms moving within the waveguide with a critical frequency higher than the resonant frequency of atoms are suggested for obtaining the "slow light". Due to the absence of the resonant mode in the guide the atoms conserves excitation and coherence. ... More
Backscattering of light by a finite two-dimensional plate in the region of excitonic absorptionJun 29 2004It is shown that the light scattered by a finite 2D crystal strip in the region of an exciton resonance should display strong backscattering. This phenomenon is related to the exciton reflection from the edge of the strip.