Results for "L. P. Cassara"

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Detailed AGB evolutionary models and near infrared colours of intermediate-age stellar populations: Tests on star clustersMar 11 2014We investigate the influence of Asymptotic Giant Branch stars on integrated colours of star clusters of ages between ~100 Myr and a few gigayears, and composition typical for the Magellanic Clouds. We use state-of-the-art stellar evolution models that ... More
GalMod: a Galactic synthesis population modelMay 01 2018We present a new Galaxy population synthesis Model (GalMod). GalMod is a star-count model featuring an asymmetric bar/bulge as well as spiral arms and related extinction. The model, initially introduced in Pasetto et al. (2016b), has been here completed ... More
A Novel Mutual Information-based Feature Selection AlgorithmJul 25 2016From a machine learning point of view to identify a subset of relevant features from a real data set can be useful to improve the results achieved by classification methods and to reduce their time and space complexity. To achieve this goal, feature selection ... More
The progeny of a Cosmic Titan: a massive multi-component proto-supercluster in formation at z=2.45 in VUDSJun 15 2018Sep 07 2018[Abridged] We unveil the complex shape of a proto-supercluster at z~2.45 in the COSMOS field using the spectroscopic redshifts of the VIMOS Ultra-Deep Survey (VUDS), complemented by the zCOSMOS-Deep sample and high-quality photometric redshifts. The method ... More
Radial distribution of dust, stars, gas, and star-formation rate in DustPedia face-on galaxiesJun 16 2017The purpose of this work is the characterization of the radial distribution of dust, stars, gas, and star-formation rate (SFR) in a sub-sample of 18 face-on spiral galaxies extracted from the DustPedia sample. This study is performed by exploiting the ... More
Old and young stellar populations in DustPedia galaxies and their role in dust heatingMar 14 2019Within the framework of the DustPedia project we investigate the properties of cosmic dust and its interaction with the stellar radiation (originating from different stellar populations) for 814 galaxies in the nearby Universe, all observed by the Herschel ... More
DustPedia: Multiwavelength Photometry and Imagery of 875 Nearby Galaxies in 42 Ultraviolet--Microwave BandsAug 17 2017The DustPedia project is capitalising on the legacy of the Herschel Space Observatory, using cutting-edge modelling techniques to study dust in the 875 DustPedia galaxies - representing the vast majority of extended galaxies within 3000 km s$^{-1}$ that ... More
Old and young stellar populations in DustPedia galaxies and their role in dust heatingMar 14 2019Apr 16 2019Within the framework of the DustPedia project we investigate the properties of cosmic dust and its interaction with the stellar radiation (originating from different stellar populations) for 814 galaxies in the nearby Universe, all observed by the Herschel ... More
DustPedia - the relationships between stars, gas and dust for galaxies residing in different environmentsApr 30 2019We use a sub-set of the DustPedia galaxy sample (461 galaxies) to investigate the effect the environment has had on galaxies. We consider Virgo cluster and field samples and also assign a density contrast parameter to each galaxy, as defined by the local ... More
A systematic metallicity study of DustPedia galaxies reveals evolution in the dust-to-metal ratiosJan 25 2019Observations of evolution in the dust-to-metal ratio allow us to constrain the dominant dust processing mechanisms. In this work, we present a study of the dust-to-metal and dust-to-gas ratios in a sub-sample of ~500 DustPedia galaxies. Using literature ... More
The stellar mass - halo mass relation from galaxy clustering in VUDS: a high star formation efficiency at z~3Dec 17 2014The relation between the galaxy stellar mass M_star and the dark matter halo mass M_h gives important information on the efficiency in forming stars and assembling stellar mass in galaxies. We present the stellar mass to halo mass ratio (SMHR) measurements ... More
The VIMOS Ultra Deep Survey First Data Release: spectra and spectroscopic redshifts of 698 objects up to z~6 in CANDELSFeb 04 2016This paper describes the first data release (DR1) of the VIMOS Ultra Deep Survey (VUDS). The DR1 includes all low-resolution spectroscopic data obtained in 276.9 arcmin2 of the CANDELS-COSMOS and CANDELS-ECFDS survey areas, including accurate spectroscopic ... More
A Cross-Entropy-based Method to Perform Information-based Feature SelectionJul 25 2016May 22 2017From a machine learning point of view, identifying a subset of relevant features from a real data set can be useful to improve the results achieved by classification methods and to reduce their time and space complexity. To achieve this goal, feature ... More
The VIMOS Ultra-Deep Survey (VUDS): fast increase of the fraction of strong Lyman alpha emitters from z=2 to z=6Mar 14 2014Oct 13 2014Aims. The aim of this work is to constrain the evolution of the fraction of Lya emitters among UV selected star forming galaxies at 2<z<6, and to measure the stellar escape fraction of Lya photons over the same redshift range. Methods. We exploit the ... More
Discovery of a rich proto-cluster at z=2.9 and associated diffuse cold gas in the VIMOS Ultra-Deep Survey (VUDS)Mar 14 2014Aug 07 2014[Abridged] We characterise a massive proto-cluster at z=2.895 that we found in the COSMOS field using the spectroscopic sample of the VIMOS Ultra-Deep Survey (VUDS). This is one of the rare structures at z~3 not identified around AGNs or radio galaxies, ... More
The VIMOS Ultra-Deep Survey: ~10,000 galaxies with spectroscopic redshifts to study galaxy assembly at early epochs 2<z<~6Mar 16 2014We present the VIMOS Ultra Deep Survey (VUDS), a spectroscopic redshift survey of ~10.000 very faint galaxies to study the major phase of galaxy assembly 2<z<~6. The survey covers 1 deg^2 in 3 separate fields: COSMOS, ECDFS and VVDS-02h, with targets ... More
The evolving SFR-M_star relation and sSFR since z~5 from the VUDS spectroscopic surveyNov 20 2014We study the evolution of the star formation rate (SFR) - stellar mass (M_star) relation and specific star formation rate (sSFR) of star forming galaxies (SFGs) since a redshift z~5.5 using 2435 (4531) galaxies with highly reliable (reliable) spectroscopic ... More
The Lyman Continuum escape fraction of galaxies at z=3.3 in the VUDS-LBC/COSMOS fieldSep 03 2015The Lyman continuum (LyC) flux escaping from high-z galaxies into the IGM is a fundamental quantity to understand the physical processes involved in the reionization epoch. We have investigated a sample of star-forming galaxies at z~3.3 in order to search ... More
A numerical method for imaging of biological microstructures by VHF wavesApr 26 2013Imaging techniques give a fundamental support to medical diagnostics during the pathology discovery as well as for the characterization of biological structures. The imaging methods involve electromagnetic waves in a frequency range that spans from some ... More
DustPedia - A Definitive Study of Cosmic Dust in the Local UniverseSep 20 2016The European Space Agency has invested heavily in two cornerstones missions; Herschel and Planck. The legacy data from these missions provides us with an unprecedented opportunity to study cosmic dust in galaxies so that we can answer fundamental questions ... More
Red giant variables: OGLE--II and MACHOSep 21 2005We review the recent impact of microlensing projects on our understanding of pulsating red giant stars. Discussed are red giant stars' pulsation properties (period--luminosity relations, period changes, mode switchings), Red Giant Branch pulsations, metallicity ... More
Exact asymptotic form of the exchange interactions between shallow centers in doped semiconductorsJun 10 2003Aug 05 2003The method developed in [L. P. Gor'kov and L. P. Pitaevskii, Sov. Phys. Dokl. 8, 788 (1964); C. Herring and M. Flicker, Phys. Rev. 134, A362 (1964)] to calculate the asymptotic form of exchange interactions between hydrogen atoms in the ground state is ... More
The Stochastic Gravitational Wave Background Generated by Cosmic String Networks: the Small-Loop RegimeMar 11 2014We consider an alternative approach for the computation of the stochastic gravitational wave background generated by small loops produced throughout the cosmological evolution of cosmic string networks and use it to derive an analytical approximation ... More
Evolution of domain wall networks: the PRS algorithmJan 17 2011The Press-Ryden-Spergel (PRS) algorithm is a modification to the field theory equations of motion, parametrized by two parameters ($\alpha$ and $\beta$), implemented in numerical simulations of cosmological domain wall networks, in order to ensure a fixed ... More
Exact Results for Kinetics of Catalytic ReactionsAug 25 1995The kinetics of an irreversible catalytic reaction on substrate of arbitrary dimension is examined. In the limit of infinitesimal reaction rate (reaction-controlled limit), we solve the dimer-dimer surface reaction model (or voter model) exactly in arbitrary ... More
On particle creation/decay in nonminimally coupled models of gravityJan 18 2019In extended models of gravity a nonminimal coupling to matter has been assumed to lead to irreversible particle creation. In this paper we challenge this assumption. We argue that a non-minimal coupling of the matter and gravitational sectors results ... More
p-brane dynamics in (N+1)-dimensional FRW universes: a unified frameworkMar 07 2011We develop a velocity-dependent one-scale model describing p-brane dynamics in flat homogeneous and isotropic backgrounds in a unified framework. We find the corresponding scaling laws in frictionless and friction dominated regimes considering both expanding ... More
Thermodynamics of Cosmic Defect Network EvolutionNov 02 2015We show that simple thermodynamic conditions determine, to a great extent, the equation of state and dynamics of cosmic defects of arbitrary dimensionality. We use these conditions to provide a more direct derivation of the Velocity-dependent One-Scale ... More
Cosmic Microwave Background anisotropies generated by domain wall networksJul 04 2015We develop a numerical tool for the fast computation of the temperature and polarization power spectra generated by domain wall networks, by extending the publicly available CMBACT code --- that calculates the CMB signatures generated by active sources ... More
The cosmological evolution of p-brane networksJul 22 2011In this paper we derive, directly from the Nambu-Goto action, the relevant components of the acceleration of cosmological featureless $p$-branes, extending previous analysis based on the field theory equations in the thin-brane limit. The component of ... More
Observational Constraints on Varying-alpha Domain WallsApr 13 2014May 05 2015We consider the possibility that current hints of spatial variations of the fine structure constant at high redshift, based on VLT/UVES and Keck/HIRES observations, could be caused by a biased domain wall network described by a scalar field non-minimally ... More
Transversality of CR mappingsOct 20 2004Jun 09 2005We prove here new results about transversality and related geometric properties of a holomorphic, formal, or CR mapping, sending one generic submanifold of $\bC^N$ into another. One of our main results is that a finite mapping is transversal to the target ... More
Reaction-Diffusion Processes with Nonlinear DiffusionJul 25 2012Oct 29 2012We study reaction-diffusion processes with concentration-dependent diffusivity. First, we determine the decay of the concentration in the single-species and two-species diffusion-controlled annihilation processes. We then consider two natural inhomogeneous ... More
Limiting Shapes of Ising Droplets, Ising Fingers, and Ising SolitonsNov 27 2011Mar 08 2012We examine the evolution of an Ising ferromagnet endowed with zero-temperature single spin-flip dynamics. A large droplet of one phase in the sea of the opposite phase eventually disappears. An interesting behavior occurs in the intermediate regime when ... More
Critical conductance of the chiral 2d random flux modelAug 27 2007Aug 29 2007The two-terminal conductance of a random flux model defined on a square lattice is investigated numerically at the band center using a transfer matrix method. Due to the chiral symmetry, there exists a critical point where the ensemble averaged mean conductance ... More
The trivial Higgs boson: first evidences from LHCJun 21 2011We further elaborate on the triviality and spontaneous symmetry breaking scenario where the Higgs boson without self-interaction coexists with spontaneous symmetry breaking. The trivial Higgs boson is rather heavy with mass m_H = 754 +/- 20 (stat) +/- ... More
Abelian chromomagnetic background field at finite temperature on the latticeJan 30 2001The vacuum dynamics of SU(2) and SU(3) lattice gauge theories is studied by means of a gauge-invariant effective action defined using the lattice Schr\"odinger functional at finite temperature. In the case of the SU(3) gauge theory numerical simulations ... More
Unstable Modes in Three-Dimensional SU(2) Gauge TheoryMar 09 1993We investigate SU(2) gauge theory in a constant chromomagnetic field in three dimensions both in the continuum and on the lattice. Using a variational method to stabilize the unstable modes, we evaluate the vacuum energy density in the one-loop approximation. ... More
Consistency of the Shannon entropy in quantum experimentsFeb 06 2003Jul 19 2004The consistency of the Shannon entropy, when applied to outcomes of quantum experiments, is analysed. It is shown that the Shannon entropy is fully consistent and its properties are never violated in quantum settings, but attention must be paid to logical ... More
Quantum Charge Transport and Conformational Dynamics of MacromoleculesFeb 14 2012We study the dynamics of quantum excitations inside macromolecules which can undergo conformational transitions. In the first part of the paper, we use the path integral formalism to rigorously derive a set of coupled equations of motion which simultaneously ... More
Study of Macroscopic Coherence and Decoherence in the SQUID by Adiabatic InversionApr 27 2000We suggest a procedure for demonstrating quantum coherence and measuring decoherence times between different fluxoid states of a SQUID by using ``adiabatic inversion'', where one macroscopic fluxoid state is smoothly transferred into the other, like a ... More
Hypercomplex quantum mechanicsFeb 01 1996The fundamental axioms of the quantum theory do not explicitly identify the algebraic structure of the linear space for which orthogonal subspaces correspond to the propositions (equivalence classes of physical questions). The projective geometry of the ... More
Warped generalized geometry compactifications, effective theories and non-perturbative effectsMar 21 2008Summarizing the results of arXiv:0707.1038, we discuss the four-dimensional effective approach to type II N=1 supersymmetric flux compactifications with general SU(3)x SU(3)-structure. In particular, we study the effect of a non-trivial warp factor, which ... More
Correlation energy of fractional-quantum-Hall-effect systems of composite fermionsNov 16 1994We find the RPA correlation energy and collective modes of the systems of composite fermions corresponding to the fillings of $1/3$, $1/5$, $2/5$ in the fractional quantum Hall effect. It is verified that transmutations to composite fermions do not change ... More
Non-equilibrium beta processes in superfluid neutron star coresApr 26 2005Dec 05 2005The influence of nucleons superfluidity on the beta relaxation time of degenerate neutron star cores, composed of neutrons, protons and electrons, is investigated. We numerically calculate the implied reduction factors for both direct and modified Urca ... More
Sphere-plate Casimir interaction in (D+1)-dimensional spacetimeDec 06 2013In this paper, we derive the formula for the Casimir interaction energy between a sphere and a plate in $(D+1)$-dimensional Minkowski spacetime. It is assumed that the scalar field satisfies the Dirichlet or Neumann boundary conditions on the sphere and ... More
Finite temperature Casimir effect on spherical shells in (D+1)-dimensional spacetime and its high temperature limitMay 10 2013We consider the finite temperature Casimir free energy acting on a spherical shell in (D+1)-dimensional Minkowski spacetime due to the vacuum fluctuations of scalar and electromagnetic fields. Dirichlet, Neumann, perfectly conducting and infinitely permeable ... More
Mode summation approach to Casimir effect between two objectsMay 11 2012Jul 17 2012In this paper, we explore the TGTG formula from the perspective of mode summation approach. Both scalar fields and electromagnetic fields are considered. In this approach, one has to first solve the equation of motion to find a wave basis for each object. ... More
Casimir interaction between a cylinder and a plate at finite temperature: Exact results and comparison to proximity force approximationJun 07 2011We study the finite temperature Casimir interaction between a cylinder and a plate using the exact formula derived from the Matsubara representation and the functional determinant representation. We consider the scalar field with Dirichlet and Neumann ... More
Finite temperature Casimir pistons for electromagnetic field with mixed boundary conditions and its classical limitJan 23 2009In this paper, the finite temperature Casimir force acting on a two-dimensional Casimir piston due to electromagnetic field is computed. It was found that if mixed boundary conditions are assumed on the piston and its opposite wall, then the Casimir force ... More
Finite temperature Casimir interaction between spheres in $(D+1)$-dimensional spacetime: Exact computations and asymptotic expansionsJun 05 2014We consider the finite temperature Casimir interaction between two Dirichlet spheres in $(D+1)$-dimensional Minkowski spacetime. The Casimir interaction free energy is derived from the zero temperature Casimir interaction energy via the Matsubara formalism. ... More
Casimir interaction between a sphere and a cylinderDec 13 2012Feb 07 2013We study the Casimir interaction between a sphere and a cylinder both subjected to Dirichlet, Neumann or perfectly conducting boundary conditions. Generalizing the operator approach developed by Wittman [IEEE Trans. Antennas Propag. 36, 1078 (1988)], ... More
Casimir interaction of concentric spheres at finite temperatureMay 12 2011Jun 23 2011We consider the finite temperature Casimir effect between two concentric spheres due to the vacuum fluctuations of the electromagnetic field in the $(D+1)$-dimensional Minkowski spacetime. Different combinations of perfectly conducting and infinitely ... More
Casimir Piston of Real Materials and its Application to Multi-Layer ModelsAug 27 2009Feb 28 2010In this article, we derive the formula for the Casimir force acting on a piston made of real material moving inside a perfectly conducting rectangular box. It is shown that by taking suitable limits, one recovers the formula for the Casimir force acting ... More
Some Uncomfortable Thoughts on the Nature of Gravity, Cosmology, and the Early UniverseMar 25 2009Apr 12 2009A specific theoretical framework is important for designing and conducting an experiment, and for interpretation of its results. The field of gravitational physics is expanding, and more clarity is needed. It appears that some popular notions, such as ... More
Statistics of the Microwave Background Anisotropies Caused by Cosmological Perturbations of Quantum-Mechanical OriginNov 27 1995The genuine quantum gravity effects can already be around us. It is likely that the observed large-angular-scale anisotropies in the microwave background radiation are induced by cosmological perturbations of quantum-mechanical origin. Such perturbations ... More
Electromagnetic Generators and Detectors of Gravitational WavesJun 03 2003The renewed serious interest to possible practical applications of gravitational waves is encouraging. Building on previous work, I am arguing that the strong variable electromagnetic fields are appropriate systems for the generation and detection of ... More
Relic Gravitational Waves and Their DetectionFeb 08 2000The range of expected amplitudes and spectral slopes of relic (squeezed) gravitational waves, predicted by theory and partially supported by observations, is within the reach of sensitive gravity-wave detectors. In the most favorable case, the detection ... More
Comment on the "Influence of Cosmological Transitions on the Evolution of Density Perturbations"Jan 06 1998Sep 17 1999A recent paper by Martin and Schwarz [1] argues that the ``standard inflationary result" has been finally proven. The result itself is formulated as: ``the closer the inflationary epoch is to the de Sitter space-time, the less important are large-scale ... More
Some properties of operator-valued framesApr 24 2015Operator-valued frames (or g-frames) are generalizations of frames and fusion frames and have been used in packets encoding, quantum computing, theory of coherent states and more. In this paper, we give a new formula for operator-valued frames for finite ... More
Thermal Lifshitz Force between Atom and Conductor with Small Density of CarriersJan 04 2008Sep 08 2008A new theory describing the interaction between atoms and a conductor with small densities of current carriers is presented. The theory takes into account the penetration of the static component of the thermally fluctuating field in the conductor and ... More
EGRET Observations of Gamma Rays from Point Sources with Galactic Latitude +10(degrees) < b < +40(degrees)Sep 05 1995The EGRET instrument aboard the Compton Gamma Ray Observatory (CGRO) has completed the first all-sky survey in high-energy gamma rays and has repeatedly viewed selected portions of the sky. Analysis of the region with galactic latitude $+10\arcdeg < b ... More
Creator-annihilator domains and the number operatorApr 03 2012We show that for the bosonic Fock representation in infinite dimensions, the maximal common domain of all creators and annihilators properly contains the domain of the square-root of the number operator.
Slopes of 2-adic overconvergent modular forms with small levelFeb 13 2003Let $\tau$ be the primitive Dirichlet character of conductor 4, let $\chi$ be the primitive even Dirichlet character of conductor 8 and let $k$ be an integer. Then the $U_2$ operator acting on cuspidal overconvergent modular forms of weight $2k+1$ and ... More
A generalisation of a congruence due to Vantieghem only holding for primesFeb 08 2004In this note we present a family of congruences which hold if and only if a natural number $n$ is prime.
A tangential approach to trigonometryFeb 07 2019We construct the complex tangent as a meromorphic function in the plane, using an approach developed by Weierstrass in his characterization of analytic functions that satisfy algebraic addition theorems.
A Grätzer-Schmidt theorem for the Lindenbaum-Tarski algebra of IPCJan 21 2016We prove a version of the Gr\"atzer-Schmidt theorem for the Lindenbaum-Tarski algebra associated to the Implicational Propositional Calculus.
Automorphisms of Liouville StructuresMar 02 2015By a Liouville structure on a symplectic manifold $(M, \omega)$ we mean a choice of symplectic potential: that is, a choice of one-form $\theta$ on $M$ such that ${\rm d} \theta = \omega$. We determine precisely all the automorphisms of a Liouville structure ... More
Automorphisms of Quadratic Liouville StructuresMar 04 2015We examine the diffeomorphisms of a symplectic vector space that preserve a chosen symplectic potential. Our examination yields an explicit description of these diffeomorphisms when the chosen potential differs from the canonical potential by the differential ... More
Bosonic PairingsOct 10 2017We extend the inner product from bosonic Fock space to a pairing between suitable antifunctionals on the symmetric algebra. Our account is illustrated by the (Gaussian) half-form pairing between positive polarizations in the form needed for geometric ... More
Three-dimensional quasi-Tonks gas in a harmonic trapApr 07 2003Jun 23 2003We analyze the macroscopic dynamics of a Bose gas in a harmonic trap with a superimposed two-dimensional optical lattice, assuming a weak coupling between different lattice sites. We consider the situation in which the local chemical potential at each ... More
Dark solitons in a two-component Bose-Einstein condensateOct 17 2000The creation and interaction of dark solitons in a two-component Bose-Einstein condensate is investigated. For a miscible case, the interaction of dark solitons in different components is studied. Various possible scenarios are presented, including the ... More
Partial Inner Products on AntidualsJun 21 2017We discuss extensions of an inner product from a vector space to its full antidual. None of these extensions is weakly continuous, but partial extensions recapture some familiar structure including the Hilbert space completion and the antiduality pairing. ... More
Bosonic kernelsApr 17 2012We show that the bosonic Fock representation of a complex Hilbert space admits a purely algebraic kernel calculus; as an illustration, we use it to reproduce the standard integral kernel formulae for metaplectic operators within the complex-wave representation. ... More
A class of solvable Lie algebras and their Casimir InvariantsNov 04 2004A nilpotent Lie algebra n_{n,1} with an (n-1) dimensional Abelian ideal is studied. All indecomposable solvable Lie algebras with n_{n,1} as their nilradical are obtained. Their dimension is at most n+2. The generalized Casimir invariants of n_{n,1} and ... More
Q-tableaux for Implicational Propositional CalculusDec 11 2015We study $Q$-tableaux and axiom systems that they engender, producing a new proof that the Implicational Propositional Calculus is complete.
Projective Space: Points and PlanesNov 12 2016We take points and planes as fundamental, lines as derived, in an axiomatic formulation of three-dimensional projective space, the self-dual nature of which formulation renders automatic the principle of duality.
Correctness of depiction in planar diagrams of spatial figuresMar 12 2014We show that it is possible to decide whether a given planar diagram correctly depicts the spatial figure consisting of a planar quadrangle together with its shadow in another plane.
Projective Space: Harmonicity and ProjectivityDec 26 2016For an axiomatization of three-dimensional projective space based on points and planes, we discuss appropriate versions of the harmonicity axiom and the projectivity axiom, showing that each axiom is equivalent to its spatial dual.
Painlevé IV and a third-order viewpointSep 27 2016We take a third-order approach to the fourth Painlev\'e equation and indicate the value of such an approach to other second-order ODEs in the Painlev\'e-Gambier list of 50.
Neville's primitive elliptic functions: the case ${\bf g_3 = 0}$Mar 22 2016The vanishing of the invariant $g_3$ attached to a lattice $\Lambda$ singles out a midpoint lattice and yields a square-root of the associated Weierstrass function $\wp_{\Lambda}$.
The Dixonian elliptic functionsJan 08 2019We offer a careful development of the Dixonian elliptic functions with parameter $\alpha = 0$ from the initial value problem of which they are solutions.
'Twisted duality' in the ${\rm C^*}$ Clifford algebraJul 12 2014Let $V$ be a real inner product space and $C[V]$ its ${\rm C}^*$ Clifford algebra. We prove that if $Z$ is a subspace of $V$ then $C[Z^{\perp}]$ coincides with the supercommutant of $C[Z]$ in $C[V]$.
Phragmén-Lindelöf theorems and p-harmonic measures for sets near low-dimensional hyperplanesMar 18 2015Dec 03 2015We prove estimates of a $p$-harmonic measure, $p \in (n-m, \infty]$, for sets in $\mathbf{R}^n$ which are close to an $m$-dimensional hyperplane $\Lambda \subset \mathbf{R}^n$, $m \in [0,n-1]$. Using these estimates, we derive results of Phragm\'en-Lindel\"of ... More
Fixation in a cyclic Lotka-Volterra modelJan 05 1998We study a cyclic Lotka-Volterra model of N interacting species populating a d-dimensional lattice. In the realm of a Kirkwood approximation, a critical number of species N_c(d) above which the system fixates is determined analytically. We find N_c=5,14,23 ... More
Spin relaxation and antisymmetric exchange in n-doped III-V semiconductorSep 05 2002Nov 07 2002Recently K. Kavokin [Phys. Rev. B 64, 075305 (2001)] suggested that the Dzyaloshinskii-Moriya interaction between localized electrons governs slow spin relaxation in $n$-doped GaAs in the regime close to the metal-insulator transition. We derive the correct ... More
Scanning Gate Spectroscopy on NanoclustersDec 09 1999A gated probe for scanning tunnelling microscopy (STM) has been developed. The probe extends normal STM operations by means of an additional electrode fabricated next to the tunnelling tip. The extra electrode does not make contact with the sample and ... More
Algebraic combinatorics on trace monoids: extending number theory to walks on graphsJan 08 2016Oct 20 2016Partially commutative monoids provide a powerful tool to study graphs, viewingwalks as words whose letters, the edges of the graph, obey a specific commutation rule. A particularclass of traces emerges from this framework, the hikes, whose alphabet is ... More
Stochastic Gravitational Wave Background generated by Cosmic String Networks: Velocity-Dependent One-Scale model versus Scale-Invariant EvolutionApr 09 2013We compute the power spectrum of the stochastic gravitational wave background generated by cosmic string networks described by the Velocity-Dependent One-Scale (VOS) model, for a wide range of macroscopic and microscopic parameters. The VOS model --- ... More
Domain wall network evolution in (N+1)-dimensional FRW universesJan 18 2011We develop a velocity-dependent one-scale model for the evolution of domain wall networks in flat expanding or collapsing homogeneous and isotropic universes with an arbitrary number of spatial dimensions, finding the corresponding scaling laws in frictionless ... More
Deterministic Soluble Model of CoarseningJul 23 1996We investigate a 3-phase deterministic one-dimensional phase ordering model in which interfaces move ballistically and annihilate upon colliding. We determine analytically the autocorrelation function A(t). This is done by computing generalized first-passage ... More
Big-bang nucleosynthesis and cosmic microwave background constraints on non-minimally coupled theories of gravityJul 02 2018In this paper we show that the baryon-to-photon ratio $\eta$ is in general not conserved before decoupling in non-minimally coupled theories of gravity. We use big-bang nucleosynthesis and cosmic microwave background limits on the baryon-to-photon ratio ... More
Impact of string and monopole-type junctions on domain wall dynamics: implications for dark energyNov 19 2009Nov 22 2009We investigate the potential role of string and monopole-type junctions in the frustration of domain wall networks using a velocity-dependent one-scale model for the characteristic velocity, $v$, and the characteristic length, $L$, of the network. We ... More
Scaling laws for weakly interacting cosmic (super)string and p-brane networksFeb 28 2012In this paper we find new scaling laws for the evolution of $p$-brane networks in $N+1$-dimensional Friedmann-Robertson-Walker universes in the weakly-interacting limit, giving particular emphasis to the case of cosmic superstrings ($p=1$) living in a ... More
Cosmological Sakharov Oscillations and Quantum Mechanics of the Early UniverseJun 26 2011May 17 2012This is a brief summary of a talk delivered at the Special Session of the Physical Sciences Division of the Russian Academy of Sciences, Moscow, 25 May 2011. The meeting was devoted to the 90-th anniversary of A. D. Sakharov. The focus of this contribution ... More
Update on gravitational-wave researchMay 13 2003Nov 04 2003The recently assembled laser-beam detectors of gravitational waves are approaching the planned level of sensitivity. In the coming 1 - 2 years, we may be observing the rare but powerful events of inspiral and merger of binary stellar-mass black holes. ... More
Vacuum Fluctuations and CosmologyMar 10 1996The notion of vacuum fluctuations of the gravitational field plays important role in cosmology. The strong variable gravitational field of the very early Universe amplifies these fluctuations and transforms them into macroscopical cosmological perturbations. ... More
The Detectability of Relic (Squeezed) Gravitational Waves by Laser InterferometersOct 17 1998Jan 15 1999It is shown that the expected amplitudes and specific correlation properties of the relic (squeezed) gravitational wave background may allow the registration of the relic gravitational waves by the first generation of sensitive gravity-wave detectors. ... More
Uncertainties and robustness of the ignition process in type Ia supernovaeJan 13 2010It is widely accepted that the onset of the explosive carbon burning in the core of a CO WD triggers the ignition of a SN Ia. The features of the ignition are among the few free parameters of the SN Ia explosion theory. We explore the role for the ignition ... More
Belief propagation for graph partitioningDec 18 2009We study the belief propagation algorithm for the graph bi-partitioning problem, i.e. the ground state of the ferromagnetic Ising model at a fixed magnetization. Application of a message passing scheme to a model with a fixed global parameter is not banal ... More