Results for "S. L. Tostado"

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Radiative corrections of $O(α)$ to $B^- \rightarrow V^0 \ell^- \barν_{\ell}$ decaysOct 27 2015Jul 22 2016The $O(\alpha)$ electromagnetic radiative corrections to the $B^- \rightarrow V^0 \ell^- \bar{\nu}_{\ell}$ ($V$ is a vector meson and $\ell$ a charged lepton) decay rates are evaluated using the cutoff method to regularize virtual corrections and incorporating ... More
A new long distance contribution to $B^\pm\to K^\pm/π^\pm\ell^+\ell-$ decaysMay 05 2015We have identified a missing long-distance (one-photon exchange) contribution to the $B^\pm\to K^\pm/\pi^\pm\ell^+\ell^-$ decays. Although it does not help to explain the anomaly measured by the LHCb Coll. in the ratio $R_K = \mathcal{B}(B^\pm\to K^\pm\mu^+\mu^-)/\mathcal{B}(B^\pm\to ... More
Long-distance weak annihilation contribution to the $B^{\pm}\to (π^{\pm},K^{\pm}) \ell^+\ell^-$ decaysMar 24 2015Sep 16 2015We propose an alternative evaluation of the long-distance weak annihilation (WA, also called one-photon exchange in this paper) contribution to the rare semileptonic $B^{\pm}\to (\pi^{\pm},K^{\pm})\ell^+\ell^-$ ($\ell=e,\,\mu$) decays. This hadronic description ... More
Deviations to Tri-Bi-Maximal mixing in the limit of $μ-τ$ symmetryMar 13 2019In the limit of an approximate $\mu-\tau$ symmetry in the neutrino mass matrix, we explore deviations to the Tri-Bi-Maximal mixing pattern in the neutrino sector. We consider two different ansatzes for the corrected pattern to predict the current values ... More
Remarks on the Standard Model predictions for $R(D)$ and $R(D^*)$Oct 13 2016Semileptonic $b \to c$ transitions, and in particular the ratios $R(D^{(*)}) = \frac{\Gamma(B \rightarrow D^{(*)} \tau \nu )}{\Gamma(B \rightarrow D^{(*)} \ell \nu )}$, can be used to test the universality of the weak interactions. In light of the recent ... More
Remarks on the Standard Model predictions for $R(D)$ and $R(D^*)$Oct 13 2016Jan 30 2017Semileptonic $b \to c$ transitions, and in particular the ratios $R(D^{(*)}) = \frac{\Gamma(B \rightarrow D^{(*)} \tau \nu )}{\Gamma(B \rightarrow D^{(*)} \ell \nu )}$, can be used to test the universality of the weak interactions. In light of the recent ... More
Spin-Wave Relaxation in a Quantum Hall FerromagnetDec 09 2008We study spin wave relaxation in quantum Hall ferromagnet regimes. Spin-orbit coupling is considered as a factor determining spin nonconservation, and external random potential as a cause of energy dissipation making spin-flip processes irreversible. ... More
Gorenstein algebras and Hochschild cohomologyApr 27 2007Apr 28 2009For homomorphism K-->S of commutative rings, where K is Gorenstein and S is essentially of finite type and flat as a K-module, the property that all non-trivial fiber rings of K-->S are Gorenstein is characterized in terms of properties of the cohomology ... More
Simulations of dual morphology in spiral galaxiesJul 04 2002Gas and stars in spiral galaxies are modelled with the DUAL code, using hydrodynamic and N-body techniques. The simulations reveal morphological differences mirroring the dual morphologies seen in B and K' band observations of many spiral galaxies. In ... More
Measuring the Higgs Boson Yukawa Couplings at an NLCMar 15 1999We investigate the inclusive production of the Higgs boson with a heavy quark pair, $t {\bar t}$ or $b {\bar b}$, in e^+e^- collisions at high energy. The ${\cal O}(\alpha_s)$ QCD corrections are included.
Binary-Induced Gravitational Collapse: A Trivial ExampleOct 20 1997We present a simple model illustrating how a highly relativistic, compact object which is stable in isolation can be driven dynamically unstable by the tidal field of a binary companion. Our compact object consists of a test-particle in a relativistic ... More
Does light exert Abraham's force in a transparent medium?Aug 04 1998Abraham's force seems to have been observed in very low frequency experiments, but the existence of an Abraham's force exerted by light is still to be proved. Twenty years ago Brevik proposed an experiment for checking what forces light exert in the interior ... More
Green Function Monte Carlo with Stochastic Reconfiguration: an effective remedy for the sign problem diseaseFeb 15 1999A recent technique, proposed to alleviate the ``sign problem disease'', is discussed in details. As well known the ground state of a given Hamiltonian $H$ can be obtained by applying the imaginary time propagator $e^{-H \tau}$ to a given trial state $\psi_T$ ... More
Analytic matrix technique for boundary value problems in applied plasticityJan 02 2007An efficient matrix formalism for finding power series solutions to boundary value problems typical for technological plasticity is developed. Hyperbolic system of two first order quasilinear PDEs that models two-dimensional plastic flow of von Mises ... More
Gravitational interaction of celestial bodies and black holes with particle dark matterJan 27 2013The particles of a dark matter due to gravitational interaction deviate from straight trajectories in the vicinity of a massive body. This causes their density to become inhomogeneous. The developed density contrast causes a gravitation attraction force ... More
Numerical simulation of ejected molten metal-nanoparticles liquefied by laser irradiation: Interplay of geometry and dewettingMar 06 2013Jun 28 2013Metallic nanoparticles, liquefied by fast laser irradiation, go through a rapid change of shape attempting to minimize their surface energy. The resulting nanodrops may be ejected from the substrate when the mechanisms leading to dewetting are sufficiently ... More
Critical Hamiltonians with long range hoppingAug 12 1999Aug 13 1999Critical states are studied by a real space RG in the problem with strong diagonal disorder and long range power law hopping. The RG flow of the distribution of coupling parameters is characterized by a family of non-trivial fix points. We consider the ... More
Observational constraints on the neutron star mass distributionSep 22 1994Radio observations of neutron star binary pulsar systems have constrained strongly the masses of eight neutron stars. Assuming neutron star masses are uniformly distributed between lower and upper bounds $m_l$ and $m_u$, the observations determine with ... More
The Radiation Reaction Effects in the BMT Model of Spinning Charge and the Radiation Polarization PhenomenonDec 19 2005The effect of radiation polarization attended with the motion of spinning charge in the magnetic field could be viewed through the classical theory of self-interaction. The quantum expression for the polarization time follows from the semiclassical relation ... More
The nu=5/2 quantum Hall state revisited: spontaneous breaking of the chiral fermion parity and phase transition between abelian and non-abelian statisticsAug 23 2001Apr 08 2002We review a recent development in the theoretical understanding of the nu=5/2 quantum Hall plateau and propose a new conformal field theory, slightly different from the Moore-Read one, to describe another universality class relevant for this plateau. ... More
Computing Expectations with Continuous P-Boxes: Univariate CaseJun 06 2009Given an imprecise probabilistic model over a continuous space, computing lower/upper expectations is often computationally hard to achieve, even in simple cases. Because expectations are essential in decision making and risk analysis, tractable methods ... More
A Model for the Quark Mass and Flavor Mixing Matrices Based on Discrete Chiral Symmetry as the Origin of FamiliesNov 19 1997Dec 01 1997We construct a model for the quark mass and flavor mixing matrices, based on the hypothesis that the flavor weak eigenstates in the three families are distinguished by a spontaneously broken discrete $Z_6$ chiral symmetry. In a leading partially symmetric ... More
Stochastic variational inference for large-scale discrete choice models using adaptive batch sizesMay 22 2014Oct 08 2015Discrete choice models describe the choices made by decision makers among alternatives and play an important role in transportation planning, marketing research and other applications. The mixed multinomial logit (MMNL) model is a popular discrete choice ... More
Elementary excitations in trapped Bose gases beyond mean field approximationJul 30 1998Using hydrodynamic theory of superfluids and the Lee-Huang-Yang equation of state for interacting Bose gases we derive the first correction to the collective frequencies of a trapped gas, due to effects beyond mean field approximation. The corresponding ... More
Uncertainty Principle and Off-Diagonal Long Range Order in the Fractional Quantum Hall EffectOct 23 1992A natural generalization of the Heisenberg uncertainty principle inequality holding for non hermitian operators is presented and applied to the fractional quantum Hall effect (FQHE). This inequality was used in a previous paper to prove the absence of ... More
On the Complex Wilson Coefficients of New Physics ScenariosNov 04 2003We draw attention on the procedure, where Standard Model predictions and experimental results are compared and certain new physics scenarios are ruled out, that requires great attention, since there is still a room for new physics, especially when contributions ... More
Fluids of platelike particles near a hard wallJul 31 2001Fluids consisting of hard platelike particles near a hard wall are investigated using density functional theory. The density and orientational profiles as well as the surface tension and the excess coverage are determined and compared with those of a ... More
Nucleon Resonance Excitation with Virtual PhotonsOct 27 2006The unitary isobar model MAID is used for a partial wave analysis of pion photoproduction and electroproduction data on the nucleon. In particular we have taken emphasis on the region of the Delta(1232) resonance and have separated the resonance and background ... More
The spatial, spectral and polarization properties of solar flare X-ray sourcesDec 28 2014Mar 06 2015X-rays are a valuable diagnostic tool for the study of high energy accelerated electrons. Bremsstrahlung X-rays produced by, and directly related to, high energy electrons accelerated during a flare, provide a powerful diagnostic tool for determining ... More
Dipolar gases in quasi one-dimensional geometriesMay 11 2007We analyze the physics of cold dipolar gases in quasi one-dimensional geometries, showing that the confinement-induced scattering resonances produced by the transversal trapping are crucially affected by the dipole-dipole interaction. As a consequence, ... More
Perturbative Renormalization of Weak-Hamiltonian Four-Fermion Operators with Overlap FermionsJul 10 2000The renormalization of the most general dimension-six four-fermion operators without power subtractions is studied at one loop in lattice perturbation theory using overlap fermions. As expected, operators with different chirality do not mix among themselves ... More
Non-ideality of quantum operations with the electron spin of a 31P donor in a Si crystal due to interaction with a nuclear spin systemDec 19 2002May 02 2003We examine a 31P donor electron spin in a Si crystal to be used for the purposes of quantum computation. The interaction with an uncontrolled system of 29Si nuclear spins influences the electron spin dynamics appreciably. The hyperfine field at the 29Si ... More
Pressure Fronts in 1D Damped Nonlinear LatticesOct 26 2009The propagation of pressure fronts (impact solutions) in 1D chains of atoms coupled by anharmonic potentials between nearest neighbor and submitted to damping forces preserving uniform motion, is investigated. Travelling fronts between two regions at ... More
Electron correlations and bond-length fluctuations in layered copper oxides: electron versus hole dopingDec 10 2005Mar 23 2006We investigate the nature of the electronic ground state and electron-lattice couplings for doped chains of CuO_4 plaquettes or CuO_6 octahedra. The undoped configuration implies here Cu 3d^9 and O 2p^6 formal valence states. The results of multiconfiguration ... More
Calibrating dipolar interaction in an atomic condensateMay 03 2004We revisit the topic of a dipolar condensate with the recently derived more rigorous pseudo-potential for dipole-dipole interaction [A. Derevianko, Phys. Rev. A {\bf 67}, 033607 (2003)]. Based on the highly successful variational technique, we find that ... More
A forgotten argument by Gordon uniquely selects Abraham's tensor as the energy-momentum tensor for the electromagnetic field in homogeneous, isotropic matterApr 21 1997Given the present status of the problem of the electromagnetic energy tensor in matter, there is perhaps use in recalling a forgotten argument given in 1923 by W. Gordon. Let us consider a material medium which is homogeneous and isotropic when viewed ... More
Existence of solutions for nonlinear p-Laplacian diference equationsJun 24 2016The aim of this paper is the study of existence of solutions for non- linear p-Laplacian difference equations. In the first part, the existence of a nontrivial homoclinic solution for a discrete p-Laplacian problem is proved. The proof is based on the ... More
Phillips symmetric operators and their extensionsJan 12 2018Jan 21 2018Let $S$ be a symmetric operator with equal defect numbers and let $\mathfrak{U}$ be a set of unitary operators in a Hilbert space $\mathfrak{H}$. The operator $S$ is called $\mathfrak{U}$-invariant if $US=SU$ for all $U\in\mathfrak{U}$. Phillips \cite{PH} ... More
On complex perturbations of infinite band Schrodinger operatorsFeb 20 2015We study a complex perturbation of a self-adjoint infinite band Schrodinger operator (defined in the form sense), and obtain the Lieb--Thirring type inequalities for the rate of convergence of the discrete spectrum of the perturbed operator to the joint ... More
On non-selfadjoint perturbations of infinite band Schrödinger operators and Kato methodOct 13 2015Let $ H_0=-\dd+V_0 $ be a multidimensional Schr\"odinger ope\-rator with a real-valued potential and infinite band spectrum, and $H=H_0+V$ be its non-selfadjoint perturbation defined with the help of Kato approach. We prove Lieb--Thirring type inequalities ... More
On continuity properties for option prices in exponential Lévy modelsApr 21 2009For a converging sequence of exponential L\'evy models, we give conditions under which the associated sequence of option prices converges. We also study the behaviour of the prices when no such convergence holds. We then consider two special cases, first ... More
Blaschke-type conditions in unbounded domains, generalized convexity and applications in perturbation theoryApr 19 2012Sep 03 2012We introduce a new geometric characteristic of compact sets on the plane called $r$-convexity, which fits nicely into the concept of generalized convexity and extends essentially the conventional convexity. For a class of subharmonic functions on unbounded ... More
Twisted Poincare duality for some quadratic Poisson algebrasSep 14 2006Nov 23 2006We exhibit a Poisson module restoring a twisted Poincare duality between Poisson homology and cohomology for the polynomial algebra R=C[X_1,...,X_n] endowed with Poisson bracket arising from a uniparametrised quantum affine space. This Poisson module ... More
Cotangent Bundles with General Natural Kahler StructuresOct 08 2008We study the conditions under which an almost Hermitian structure $(G,J)$ of general natural lift type on the cotangent bundle $T^*M$ of a Riemannian manifold $(M,g)$ is K\" ahlerian. First, we obtain the algebraic conditions under which the manifold ... More
Duality from Topological SymmetryNov 23 1998Dec 17 1998We describe topological gauge theories for which duality properties are encoded by construction. We study them for compact manifolds of dimensions four, eight and two. The fields and their duals are treated symmetrically, within the context of field--antifield ... More
Abundance determination in HII regions from spectra without the [OII]3727+3729 lineNov 05 2010We suggest an empirical calibration for determination of oxygen and nitrogen abundances and electron temperature in HII regions where the [OII]3727+3729 line (R_2) is not available. The calibration is based on the strong emission lines of OIII, NII, and ... More
Entanglement of spin-1/2 Heisenberg Antiferromagnetic quantum spin chainsMay 14 2016The quantum entanglement measure is determined, for the first time, for a collection of spin-1/2 arranged in a infinite chain with finite temperature and applied to a single-crystal \beta-\mathrm{T_eVO_4}. The physical quantity proposed here to measure ... More
Andre-Quillen homology of algebra retractsOct 02 2002Given a homomorphism of commutative noetherian rings $\phi: R \to S$, Daniel Quillen conjectured in 1970 that if the Andre-Quillen homology functors $D_n(S|R,-)$ vanish for all $n \gg 0$, then they vanish for all $n \ge 3$. We prove the conjecture under ... More
Bar mode instability in relativistic rotating stars: a post Newtonian treatmentNov 17 1997We construct analytic models of incompressible, rigidly rotating stars in PN gravity and study their stability against nonaxisymmetric Jacobi-like bar modes. PN configurations are modeled by homogeneous triaxial ellipsoids and the metric is obtained as ... More
Insights into the Second Law of Thermodynamics from Anisotropic Gas-Surface InteractionsSep 16 2006Thermodynamic implications of anisotropic gas-surface interactions in a closed molecular flow cavity are examined. Anisotropy at the microscopic scale, such as might be caused by reduced-dimensionality surfaces, is shown to lead to reversibility at the ... More
Understanding critical behavior in the framework of the extended equilibrium fluctuation theoremJan 17 2012Recently (arXiv:0910.2870), we have derived a fluctuation theorem for systems in thermodynamic equilibrium compatible with anomalous response functions, e.g. the existence of states with \textit{negative heat capacities} $C<0$. In this work, we show that ... More
Equilibrium fluctuation theorems compatible with anomalous responseOct 15 2009Jan 17 2012Previously, we have derived a generalization of the canonical fluctuation relation between heat capacity and energy fluctuations $C=\beta^{2}<\delta U^{2}>$, which is able to describe the existence of macrostates with negative heat capacities $C<0$. In ... More
Uncertainty relations of Statistical MechanicsOct 15 2009Recently, we have presented some simple arguments supporting the existence of certain complementarity between thermodynamic quantities of temperature and energy, an idea suggested by Bohr and Heinsenberg in the early days of Quantum Mechanics. Such a ... More
Spectral Anomaly and High Temperature SuperconductorsNov 17 1995Spectral anomaly for interacting Fermions is characterized by the spectral function $A([k-k_F],\omega)$ satisfying the scaling relation $A(\Lambda^{y_1} [k-k_F],\Lambda^{y_2}\omega)= \Lambda^{y_A}A([k-k_F],\omega)$, where $y_1$, $y_2$, and $y_A$ are the ... More
Weyl transformations and trace anomalies in N=1, D=4 supergravitiesMay 30 2013Jul 07 2013We identify the supersymmetric extension of Weyl transformations in various types of supergravities, the minimal, nonminimal and new minimal N=1 SUGRA in 4D, formulated in terms of superfields. Based also on previous results we conclude that there are ... More
Equisingularity, Multiplicity, and DependenceMay 13 1998This is a report on some recent work by Gaffney, Massey, and the author, characterizing the conditions A_f and W_f for a family of ICIS germs equipped with a function. First we introduce the work informally. Then we review the formal definitions of A_f ... More
Phases of massive gravitySep 13 2004Nov 18 2004We systematically study the most general Lorentz-violating graviton mass invariant under three-dimensional Eucledian group using the explicitly covariant language. We find that at general values of mass parameters the massive graviton has six propagating ... More
Star tracks in the ghost condensateMar 31 2004Jul 30 2004We consider the infrared modification of gravity by ghost condensate. Naively, in this scenario one expects sizeable modification of gravity at distances of order 1000 km, provided that the characteristic time scale of the theory is of the order of the ... More
First evidence for Casimir scaling in G(2) lattice gauge theoryNov 21 2008Potentials between static quarks and antiquarks from a few lowest representations were evaluated in numerical simulations of 4-dimensional pure G$_2$ lattice gauge theory at various couplings. The obtained potentials are linearly rising at intermediate ... More
Fast Condensation in a tunable Backgammon modelJan 24 2006We present a Monte Carlo study of the Backgammon model, at zero temperature, in which a departure box is chosen at random with a probability proportional to $(2\omega - 1)k + (1 - \omega)N$, where $k$ is the number of particles in the departure box and ... More
Binary neutron star inspiral, LIGO, and cosmologyFeb 06 1995Recent work on the expected event rate of neutron star inspiral signals in the LIGO detector is summarized. The observed signals will be from inspirals at cosmological distances, and the important cosmological effects on the event rate and spectrum are ... More
Testing GRBs as Standard CandlesMay 07 2008Sep 02 2008Several correlations among Gamma Ray Burst (GRB) observables with available redshifts have been recently identified. Proper evaluation and calibration of these correlations may facilitate the use of GRBs as standard candles constraining the expansion ... More
Measuring the Higgs Yukawa Couplings at a Next Linear ColliderOct 04 1999We investigate the inclusive production of a Higgs boson with a pair of heavy quarks (t-tbar b-bbar), in e^+e^- collisions at high energies, sqrt(s)=500 GeV and sqrt(s)=1 TeV. We consider both the Standard Model and the supersymmetric case. In both cases ... More
Next-to-Leading Order Results for t-tbar-h Production at the TevatronJul 09 2001We compute the O(alpha_s^3) total cross section for the process (p pbar -> t tbar h) in the Standard Model, at \sqrt{s}=2 TeV. The next-to-leading order corrections drastically reduce the renormalization and factorization scale dependence of the Born ... More
One thing that general relativity says about photons in matterJun 19 2001Jul 26 2001Let us abandon for a moment the strict epistemological standpoint of quantum field theory, that eventually comes to declare nonsensical any question about the photon posed outside the quantum theoretical framework. We can then avail of the works by Whittaker ... More
Notes on parafermionic QFT's with boundary interactionJun 16 2006The main result of these notes is an analytical expression for the partition function of the circular brane model for arbitrary values of the topological angle. The model has important applications in condensed matter physics. It is related to the dissipative ... More
Comment on "Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system" (A. P. Drozdov et al., Nature 525, 73 (2015))Oct 01 2015It is demonstrated that resistive transition at 203 K observed in metallic sulfur hydride system at high pressure can be magnetic (rather than superconducting (SC)) in nature. The onset temperature of genuine superconducting transition in these compounds ... More
Properties of ferroelectric nanodots embedded in a polarizable medium: Atomistic simulationsSep 28 2006An atomistic approach is used to investigate finite-temperature properties of ferroelectric nanodots that are embedded in a polarizable medium. Different phases are predicted, depending on the ferroelectric strengths of the material constituting the dot ... More
Blaschke-type conditions for analytic functions in the unit disk: inverse problems and local analogsJul 18 2010We continue the study of analytic functions in the unit disk of finite order with arbitrary set of singular points on the unit circle, introduced in \cite{FG}. The main focus here is made upon the inverse problem: the existence of a function from this ... More
Sandage versus Hubble on the reality of the expanding universeMay 11 2006Jul 03 2006A critical reading of Lubin & Sandage's 2001 paper on the Tolman effect for the reality of the expansion of the universe clearly reveals that Sandage is far from winning the dispute with Hubble on the issue. After all the years, Hubble's doubt about the ... More
Newtonian gravitational deflection of light revisitedAug 03 2005Apr 17 2009The angle of deflection of a light ray by the gravitational field of the Sun, at grazing incidence, is calculated by strict and straightforward classical Newtonian means using the corpuscular model of light. The calculation is presented in the historical ... More
Analysis of the DeltaI=1/2 Rule and e'/e with Overlap FermionsNov 16 2000Apr 04 2001We study the renormalization of the DeltaS=1 effective weak Hamiltonian with overlap fermions. The mixing coefficients among dimension-six operators are computed at one loop in perturbation theory. As a consequence of the chiral symmetry at finite lattice ... More
Virtual and real processes, the Källén function, and the relation to dilogarithmsApr 30 2014Jul 14 2015We enlighten relations between the K\"all\'en function, allowing in a simple way to distinguish between virtual and real processes involving massive particles, and the dilogarithms occurring as results of loop calculations for such kind of processes.
Probing dipolar effects with condensate shape oscillationNov 14 2001Mar 26 2002We discuss the low energy shape oscillations of a magnetic trapped atomic condensate including the spin dipole interaction. When the nominal isotropic s-wave interaction strength becomes tunable through a Feshbach resonance (e.g. as for $^{85}$Rb atoms), ... More
A Blaschke-type condition for analytic functions on finitely connected domains. Applications to complex perturbations of a finite-band selfadjoint operatorJun 04 2011This is a sequel of a recent article by Borichev-Golinskii-Kupin, where the authors obtain Blaschke-type conditions for special classes of analytic functions in the unit disk which satisfy certain growth hypotheses. These results were applied to get Lieb-Thirring ... More
A Blaschke-type condition for analytic and subharmonic functions and application to contraction operatorsApr 20 2008Jun 27 2009Let $E$ be a closed set on the unit circle. We find a Blaschke-type condition, optimal in a sense of the order, on the Riesz measure of a subharmonic function $v$ in the unit disk with a certain growth at the direction of $E$. In particular case when ... More
Centralizing automorphisms and Jordan left derivations on $σ$-prime ringsFeb 04 2009Let $R$ be a 2-torsion free $\sigma$-prime ring. It is shown here that if $U\not\subset Z(R)$ is a $\sigma$-Lie ideal of $R$ and $a, b$ in $R$ such that $aUb=\sigma(a)Ub=0,$ then either $a=0$ or $b=0.$ This result is then applied to study the relationship ... More
Conformally flat tangent bundles with general natural lifted metricsOct 09 2008We study the conditions under which the tangent bundle $(TM,G)$ of an $n$-dimensional Riemannian manifold $(M,g)$ is conformally flat, where $G$ is a general natural lifted metric of $g$. We prove that the base manifold must have constant sectional curvature ... More
On a Blaschke-type condition for subharmonic functions with two sets of singularities on the boundaryJan 09 2019Given two compact sets, $E$ and $F$, on the unit circle, we study the class of subharmonic functions on the unit disk which can grow at the direction of $E$ and $F$ (sets of singularities) at different rate. The main result concerns the Blaschke-type ... More
A note on the complete rotational invariance of biradial solutions to semilinear elliptic equationsJul 19 2010We investigate symmetry properties of solutions to equations of the form $$ -\Delta u = \frac{a}{|x|^2} u + f(|x|, u)$$ in R^N for $N \geq 4$, with at most critical nonlinearities. By using geometric arguments, we prove that solutions with low Morse index ... More
Strong commutativity preserving maps on Lie ideals of semiprime ringsFeb 04 2009Let $R$ be a 2-torsion free semiprime ring and $U$ a nonzero square closed Lie ideal of $R$. In this paper it is shown that if $f$ is either an endomorphism or an antihomomorphism of $R$ such that $f(U)=U,$ then $f$ is strong commutativity preserving ... More
Locally linear embedding: dimension reduction of massive protostellar spectraJun 22 2016We present the results of the application of locally linear embedding (LLE) to reduce the dimensionality of dereddened and continuum subtracted near-infrared spectra using a combination of models and real spectra of massive protostars selected from the ... More
The Discovery of 8.7s Pulsations from the Ultrasoft X-Ray Source 4u0142+614Jul 28 1994We discovered a periodicity at about 8.7s from the X--ray sources 4U0142+61, previously considered a possible black hole candidate on the basis of its ultrasoft spectrum. The pulsations are visible only in the 1--4 keV energy range, during an observation ... More
Theory of gravity admitting arbitrary choice of the energy density reference levelSep 03 2016Jan 08 2019Five-vectors theory of gravity is proposed, which admits an arbitrary choice of the energy density reference level. This theory is formulated as the constraint theory, where the Lagrange multipliers turn out to be restricted to some class of vector fields ... More
Experiments in Principle for the Artscience (AS) Interpretation: Paper IISep 27 2005Sep 28 2005The physics of wavefunction collapse from Hilbert space to a classically real spacetime, accompanied by wave-particle duality, is, fundamentally, reduction of the complex psi to reality. We introduce new terminology for new physics. The superposition ... More
Algebra of the observables in the Calogero model and in the Chern-Simons matrix modelMar 26 2002Oct 18 2002The algebra of observables of an N-body Calogero model is represented on the S_N-symmetric subspace of the positive definite Fock space. We discuss some general properties of the algebra and construct four different realizations of the dynamical symmetry ... More
Electrodynamic forces in elastic matterDec 03 1999A macroscopic theory for the dynamics of elastic, isotropic matter in presence of electromagnetic fields is proposed here. We avail of Gordon's general relativistic derivation of Abraham's electromagnetic energy tensor as starting point. The necessary ... More
Functional kernel estimators of conditional extreme quantilesDec 05 2012We address the estimation of "extreme" conditional quantiles i.e. when their order converges to one as the sample size increases. Conditions on the rate of convergence of their order to one are provided to obtain asymptotically Gaussian distributed kernel ... More
An exhaustive list of isotropic apocalyptic scenariosSep 26 2016We study the possible types of future singularities in the isotropic homogeneous cosmological models for the arbitrary equation of state of the contents of the Universe. We obtain all known types of these singularities as well as two new types using a ... More
Vacuum Energy and Casimir Force in a Presence of Skin-depth Dependent Boundary ConditionMar 25 2000The vacuum energy-momentum tensor (EMT) and the vacuum energy corresponding to massive scalar field on $\Re_{t}\times [0,l] \times \Re^{D-2}$ space-time with boundary condition involving a dimensional parameter ($\delta$) are found. The dependent on the ... More
Planck scale effects and the suppression of power on the large scales in the primordial spectrumOct 07 2004The enormous red-shifting of the modes during the inflationary epoch suggests that physics at the very high energy scales may modify the primordial perturbation spectrum. Therefore, the measurements of the anisotropies in the Cosmic Microwave Background ... More
Path integral duality and Planck scale corrections to the primordial spectrum in exponential inflationAug 31 2006The enormous red-shifting of the modes during the inflationary epoch suggests that physics at the Planck scale may modify the standard, nearly, scale-invariant, primordial, density perturbation spectrum. Under the principle of path-integral duality, the ... More
Hardy's inequality for fractional powers of the sublaplacian on the Heisenberg groupAug 04 2015Jul 14 2016We prove Hardy inequalities for the conformally invariant fractional powers of the sublaplacian on the Heisenberg group $\mathbb{H}^n$. We prove two versions of such inequalities depending on whether the weights involved are non-homogeneous or homogeneous. ... More
A linear algorithm for the identification of a weakly singular relaxation kernel using two boundary measurementsSep 26 2016We consider a distributed system of a type which is encountered in the study of diffusion processes with memory and in viscoelasticity. The key feature of such system is the persistence in the future of the past actions due the memory described via a ... More
Observations of the Galactic Center Region with Beppo-SaxDec 18 1998We are performing a survey of the Galactic Center region with the BeppoSAX satellite. Several known point sources are visible (including one at the position of SgrA*), as well as newly discovered sources and diffuse emission. Here we report the preliminary ... More
Effective dynamics for particles coupled to a quantized scalar fieldFeb 19 2007Oct 01 2007We consider a system of N non-relativistic spinless quantum particles (``electrons'') interacting with a quantized scalar Bose field (whose excitations we call ``photons''). We examine the case when the velocity v of the electrons is small with respect ... More
Interference of Bose-Einstein condensates in momentum spaceMay 27 1999We suggest an experiment to investigate the linear superposition of two spatially separated Bose-Einstein condensates. Due to the coherent combination of the two wave functions, the dynamic structure factor, measurable through inelastic photon scattering ... More
On number of hypersurfaces containing projective curvesApr 04 1995Generalizing a classical lemma of Castelnuovo, we characterize rational normal curves (resp. linearly normal elliptic curves) as curves $C\subset \PP^n$ such that the number of linearly independent hypersurfaces $Z\supset C$ of given degree~$m$ is maximal ... More
The power spectrum of the Lyman--$α$ cloudsSep 16 1997We estimate the 1--D power spectrum and the integral density of neighbors in 14 QSO lines of sight. We discuss their variation with respect to redshift and column density and compare the results with standard CDM models.
Bouncing Brane Cosmologies from Warped String CompactificationsMay 21 2002May 30 2002We study the cosmology induced on a brane probing a warped throat region in a Calabi-Yau compactification of type IIB string theory. For the case of a BPS D3-brane probing the Klebanov-Strassler warped deformed conifold, the cosmology described by a suitable ... More