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Do cement nanoparticles exist in space ?Apr 29 2014The calcium-silicate-hydrate is used to model properties of cement on Earth. We study cementitious nanoparticles and propose these structures as components of cosmic dust grains. Quantum density functional theory methods are applied for the calculation ... More

A connected multidimensional maximum bisection problemDec 02 2015The maximum graph bisection problem is a well known graph partition problem. The problem has been proven to be NP-hard. In the maximum graph bisection problem it is required that the set of vertices is divided into two partition with equal number of vertices, ... More

A multidimensional maximum bisection problemJun 25 2015This work introduces a multidimensional generalization of the maximum bisection problem. A mixed integer linear programming formulation is proposed with the proof of its correctness. The numerical tests, made on the randomly generated graphs, indicates ... More

On the Effect of the Interplanetary Medium on Nanodust Observations by the Solar Terrestrial Relations ObservatoryJan 12 2015New measurements using radio and plasma-wave instruments in interplanetary space have shown that nanometer-scale dust, or nanodust, is a significant contributor to the total mass in interplanetary space. Better measurements of nanodust will allow us to ... More

Demonstrating Universal Scaling in Quench Dynamics of a Yukawa One-Component PlasmaOct 26 2015The Yukawa one-component plasma (OCP) is a paradigm model for describing plasmas that contain one component of interest and one or more other components that can be treated as a neutralizing, screening background. In appropriately scaled units, interactions ... More

A transonic collisionless model of the solar windFeb 15 2004Because of the semi-collisional nature of the solar wind, the collisionless or exospheric approach as well as the hydrodynamic one are both inaccurate. However, the advantage of simplicity makes them useful for enlightening some basic mechanisms of solar ... More

Acceleration of weakly collisional solar-type windsMay 16 2005One of the basic properties of the solar wind, that is the high speed of the fast wind, is still not satisfactorily explained. This is mainly due to the theoretical difficulty of treating weakly collisional plasmas. The fluid approach implies that the ... More

Coexistence of orbital and quantum critical magnetoresistance in FeSe$_{1-x}$S$_{x}$Mar 13 2019The recent discovery of a non-magnetic nematic quantum critical point (QCP) in the iron chalcogenide family FeSe$_{1-x}$S$_{x}$ has raised the prospect of investigating, in isolation, the role of nematicity on the electronic properties of correlated metals. ... More

Dust detection by the wave instrument on STEREO: nanoparticles picked up by the solar wind?Mar 24 2009Apr 04 2009The STEREO/WAVES instrument has detected a very large number of intense voltage pulses. We suggest that these events are produced by impact ionisation of nanoparticles striking the spacecraft at a velocity of the order of magnitude of the solar wind speed. ... More

Whistler mode waves and the electron heat flux in the solar wind: Cluster observationsOct 22 2014The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations ... More

Interplanetary Nanodust Detection by the Solar Terrestrial Relations Observatory/WAVES Low Frequency ReceiverMar 05 2013New measurements using radio and plasma-wave instruments in interplanetary space have shown that nanometer-scale dust, or nanodust, is a significant contributor to the total mass in interplanetary space. Better measurements of nanodust will allow us to ... More

Anisotropy in the Magnetoresistance Scaling of BaFe$_2$(As$_{1-x}$P$_{x}$)$_2$May 24 2018Theories of the strange metal, the parent state of many high temperature superconductors, invariably involve an important role for correlations in the spin and charge degrees of freedom. The most distinctive signature of this state in the charge transport ... More

Boosted objects: a probe of beyond the Standard Model physicsDec 24 2010Jul 16 2011We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the ... More

A zone of preferential ion heating extends tens of solar radii from SunAug 18 2017The extreme temperatures and non-thermal nature of the solar corona and solar wind arise from an unidentified physical mechanism that preferentially heats certain ion species relative to others. Spectroscopic indicators of unequal temperatures commence ... More

Missing Fe: hydrogenated iron nanoparticlesNov 01 2016Although it was found that the FeH lines exist in the spectra of some stars, none of the spectral features in the ISM have been assigned to this molecule. We suggest that iron atoms interact with hydrogen and produce Fe-H nanoparticles which sometimes ... More

On the mechanism of radio emission in type III Solar RadioburstsDec 26 2018Type III solar radio bursts are generated by streams of energetic electrons accelerated at the Sun during periods of the solar activity. The generation occurs in two steps. Initially, electron beams generate electrostatic Langmuir waves and then these ... More

Spacecraft charging and ion wake formation in the near-Sun environmentJun 04 2010A three-dimensional (3-D), self-consistent code is employed to solve for the static potential structure surrounding a spacecraft in a high photoelectron environment. The numerical solutions show that, under certain conditions, a spacecraft can take on ... More

Precision Spectroscopy of Atomic Hydrogen and Variations of Fundamental ConstantsNov 26 2003Jul 27 2004In 2003 we have measured the absolute frequency of the $(1S, F=1, m_F=\pm 1) \leftrightarrow (2S, F'=1, m_F'=\pm 1)$ two-photon transition in atomic hydrogen. We observed a variation of $(-29\pm 57)$ Hz over a 44 months interval separating this measurement ... More

Formulae for the Analysis of the Flavor-Tagged Decay B^0_s --> Jpsi phiAug 25 2010Nov 29 2010Differential rates in the decay B^0_s --> Jpsi phi, with phi --> K^+K^- and Jpsi --> mu^+ mu^- are sensitive to the CP-violation phase beta_s, predicted to be very small in the standard model. The analysis of B^0_s --> Jpsi phi decays is also suitable ... More

Fluid theory of coherent magnetic vortices in high-beta space plasmasMay 08 2017Jun 11 2018In-situ observations in the Earth's and Saturn's magnetosheaths and in the solar wind reveal the presence of Alfv\'en vortices as intermittent structures in the range of scales from tens to several ion scales. These magnetic vortices appear compressible ... More

Wave fronts via Fourier series coefficientsJul 15 2014Apr 14 2015Motivated by the product of periodic distributions, we give a new description of the wave front and the Sobolev-type wave front of a distribution $f\in\mathscr{D}'(\mathbb{R}^d)$ in terms of Fourier series coefficients.

Statistical Survey of Type III Radio Bursts at Long Wavelengths Observed by the Solar TErrestrial RElations Observatory (STEREO)/Waves Instruments: Goniopolarimetric Properties and Radio Source LocationsOct 21 2014We have performed statistical analysis of a large number of Type III radio bursts observed by STEREO between May 2007 and February 2013. Only intense, simple, and isolated cases have been included in our data set. We have focused on the goniopolarimetric ... More

Gyrokinetic theory of magnetic structures in high-beta plasmas of the Earths magnetopause and of the slow solar windMay 08 2017Nonlinear effects of the trapping of resonant particles by the combined action of the electric field and the magnetic mirror force is studied using a gyrokinetic description that includes the finite Larmor radius effects. A general nonlinear solution ... More

Solar wind turbulent spectrum at plasma kinetic scalesDec 03 2012The description of the turbulent spectrum of magnetic fluctuations in the solar wind in the kinetic range of scales is not yet completely established. Here, we perform a statistical study of 100 spectra measured by the STAFF instrument on the Cluster ... More

New Limits to the Drift of Fundamental Constants from Laboratory MeasurementsDec 12 2003Jun 04 2004We have remeasured the absolute $1S$-$2S$ transition frequency $\nu_{\rm {H}}$ in atomic hydrogen. A comparison with the result of the previous measurement performed in 1999 sets a limit of $(-29\pm 57)$ Hz for the drift of $\nu_{\rm {H}}$ with respect ... More

Cold Atom Clocks, Precision Oscillators and Fundamental TestsOct 04 2003We describe two experimental tests of the Equivalence Principle that are based on frequency measurements between precision oscillators and/or highly accurate atomic frequency standards. Based on comparisons between the hyperfine frequencies of 87Rb and ... More

Asymmetry of $^{56}$Ni ejecta and polarization in type IIP supernova 2004djAug 21 2006I study a problem, whether the asymmetry of a $^{56}$Ni ejecta that results in the asymmetry of the H$\alpha$ emission line at the nebular epoch of the type IIP supernova SN 2004dj is able also to account for the recently detected polarization of the ... More

Non-Abelian Lovelock-Born-Infeld Topological Black HolesSep 02 2009Oct 24 2009We present the asymptotically AdS solutions of the Einstein gravity with hyperbolic horizons in the presence of $So(n(n-1)/2-1, 1)$ Yang-Mills fields governed by the non-Abelian Born-Infeld lagrangian. We investigate the properties of these solutions ... More

Gaussian measures associated to the higher order conservation laws of the Benjamin-Ono equationSep 24 2011Jul 04 2012Inspired by the work of Zhidkov on the KdV equation, we perform a construction of weighted gaussian measures associated to the higher order conservation laws of the Benjamin-Ono equation. The resulting measures are supported by Sobolev spaces of increasing ... More

Stability of the Lepton-Flavor Mixing Matrix Against Quantum CorrectionsJun 24 1999Recent neutrino experiments suggest the strong evidences of tiny neutrino masses and the lepton-flavor mixing. Neutrino-oscillation solutions for the atmospheric neutrino anomaly and the solar neutrino deficit can determine the texture of neutrino mass ... More

Yukawa Interaction from a SUSY Composite ModelSep 04 1997We present a composite model that is based on non-perturbative effects of N=1 supersymmetric SU(N_C) gauge theory with N_f=N_C+1 flavors. In this model, we consider N_C=7, where all matter fields in the supersymmetric standard model, that is, quarks, ... More

Static Configurations of Dark Energy and Dark MatterSep 26 2005Dec 08 2005We study static configurations of dark matter coupled to a scalar field responsible for the dark energy of the Universe. The dark matter is modelled as a Fermi gas within the Thomas-Fermi approximation. The mass of the dark matter particles is a function ... More

An example of a 16-vertex Folkman edge (3,4)-graph without 8-cliquesFeb 12 2006In this paper we prove a new upper bouhd on an edge Folkman number. In a previous paper we have proved that this bound is exact.

Invariant measure for a three dimensional nonlinear wave equationJul 10 2007We study the long time behavior of the subcritical (subcubic) defocussing nonlinear wave equation on the three dimensional ball, for random data of low regularity. We prove that for a large set of radial initial data in $\cap_{s<1/2} H^s(B(0,1))$ the ... More

Modified Gauss-Newton method in low-rank signal estimationMar 04 2018The paper is devoted to the solution of a weighted non-linear least-squares problem for low-rank signal estimation, which is related Hankel structured low-rank approximation problems. The solution is constructed by a modified weighted Gauss-Newton method. ... More

SN 2011ht: Weak explosion in massive extended envelopeOct 21 2015Oct 29 2015A possibility is explored to account for the light curve and the low expansion velocity of the supernova SN~2011ht, a member of group of three objects showing signatures of both IIn and IIP supernovae. It is argued that the radiated energy and the expansion ... More

Affine metrics and algebroid structures: Application to general relativity and unificationAug 14 2011Affine metrics and its associated algebroid bundle are developed. Theses structures are applied to the general relativity and provide an structure for unification of gravity and electromagnetism. The final result is a field equation on the associated ... More

$ΔS = 1$ Hadronic Weak Decays of Hyperons in a Soliton ModelSep 23 1997We study the parity violating hyperon non-leptonic weak decays in the three flavor Skyrme model. We follow the approach in which the symmetry breaking terms in the action are diagonalized exactly within the collective coordinate approximation. We show ... More

Fate of k_perp-factorization for hard processes in nuclear environmentDec 15 2004Large thickness of heavy nuclei brings in a new scale into the pQCD description of hard processes in nuclear environment. The familiar linear $k_{\perp}$-factorization breaks down and must be replaced by a new concept of the nonlinear $k_{\perp}$-factorization ... More

The Electron Temperature and Anisotropy in the Solar Wind. I. Comparison of the Core and Halo PopulationsFeb 26 2016Estimating the temperature of the solar wind particles and their anisotropies is particularly important for understanding the origin of these deviations from thermal equilibrium as well as their effects. In the absence of energetic events the velocity ... More

Identifying boosted new physics with non-isolated leptonsOct 01 2014Jan 25 2015We demonstrate the utility of leptons which fail standard isolation criteria in searches for new physics at the LHC. Such leptons can arise in any event containing a highly boosted particle which decays to both leptons and quarks. We begin by considering ... More

Henon-Heiles Hamiltonian for Coupled Upper-Hybrid and Magnetoacoutic Waves in Magnetized PlasmasJul 24 1995We show that the coupled mode equations for the stationary propagation of upper--hybrid and magnetoacoustic waves in magnetized electron--ion plasmas with negative group dispersion can be exactly derived from the generalized \Henon--Heiles Hamiltonian. ... More

Circumstellar Na I and Ca II lines of type Ia supernovae in symbiotic scenarioJan 29 2008Formation of circumstellar lines of Na I and Ca II in type Ia supernovae is studied for the case, when supernova explodes in a binary system with a red giant. The model suggests a spherically-symmetric wind and takes into account ionization and heating ... More

Broad emission lines from opaque electron-scattering environment of SN 1998SJun 13 2001I propose that broad narrow-topped emission lines with full width at zero intensity >20000 km/s, seen in early-time spectra of SN 1998S, originate from a dense circumstellar gas and not from the supernova ejecta. The tremendous line width is the result ... More

Circumstellar interaction in type Ibn supernovae and SN 2006jcAug 05 2009I analyse peculiar properties of light curve and continua of enigmatic Ibn supernovae, including SN 2006jc, and argue in favour of the early strong circumstellar interaction. This interaction explains the high luminosity and fast flux rise of SN 1999cq, ... More

Light Scalar Mesons as Manifestation of Spontaneously Broken Chiral SymmetryJan 20 2010Attention is paid to the production mechanisms of light scalars that reveal their nature. We reveal the chiral shielding of the \sigma(600) meson. We show that the kaon loop mechanism of the \phi radiative decays, ratified by experiment, points to the ... More

Strong decays of P wave baryons in the $1/N_c$ expansionApr 18 2005The hadronic decays of non-strange negative parity baryons are analyzed in the framework of the 1/Nc expansion. A complete basis of spin-flavor operators for the pseudoscalar meson S and D partial wave amplitudes is established to order 1/Nc and the unknown ... More

Two and Three parametric regular generalizations of spherically symmetric and axially symmetric metricsNov 22 2002Regular generalizations of spherically and axially symmetric metrics and their properties are considered. Newton gravity law generalizations are reduced for null geodesic.

Stripes ordering in self-stratification experiments of binary and ternary granular mixturesApr 25 2000The self-stratification of binary and ternary granular mixtures has been experimentally investigated. Ternary mixtures lead to a particular ordering of the strates which was not accounted for in former explanations. Bouncing grains are found to have an ... More

Spin Dependence of Diffractive Vector Meson ProductionAug 24 1999Aug 26 1999I review the recent progress in the theory of s-channel helicity nonconservation (SCHNC) effects in diffractive DIS. SCHNC in diffractive vector meson production is an unique probe of the spin-orbit coupling and Fermi motion of quarks in vector mesons. ... More

Helicity Flip in Diffractive DISAug 26 1999I review new results on s-channel helicity nonconservation (SCHNC) in diffractive DIS. I discuss how by virtue of unitarity diffractive DIS gives rise to spin structure functions which were believed to vanish at x << 1. These include tensor polarization ... More

Asymptotic behaviour of the total cross section of p-p scattering and the Akeno cosmic ray dataApr 21 1993I present a new determination of the total cross section for proton-proton collisions from the recent Akeno results on absorption of the cosmic ray protons in the p-Air collisions. Extrapolation to the SSC energy suggests $\sigma_{tot}(p-p) \approx (160-170) ... More

POLAR Investigation of the Sun - POLARISMay 28 2008Jun 23 2008The POLAR Investigation of the Sun (POLARIS) mission uses a combination of a gravity assist and solar sail propulsion to place a spacecraft in a 0.48 AU circular orbit around the Sun with an inclination of 75 degrees with respect to solar equator. This ... More

Effective quantum number for axially symmetric problemsAug 15 2014We generalize the universal effective quantum number introduced earlier for centrally symmetric problems. The proposed number determines the semiclassical quantization condition for axially symmetric potentials.

Propagation of a Dark Soliton in a Disordered Bose-Einstein CondensateJun 01 2005Sep 26 2005We consider the propagation of a dark soliton in a quasi 1D Bose-Einstein condensate in presence of a random potential. This configuration involves nonlinear effects and disorder, and we argue that, contrarily to the study of stationary transmission coefficients ... More

Unnatural Oscillon Lifetimes in an Expanding BackgroundApr 19 2006Jul 11 2006We consider a classical toy model of a massive scalar field in 1+1 dimensions with a constant exponential expansion rate of space. The nonlinear theory under consideration supports approximate oscillon solutions, but they eventually decay due to their ... More

Non-linear Matter Spectrum for a Variable Equation of StateFeb 17 2010Apr 10 2014We study the growth of matter perturbations beyond the linear level in cosmologies in which the dark energy has a variable equation of state. The non-linear corrections result in shifts in the positions of the maximum, minima and nodes of the spectrum ... More

Chern invariants of some flat bundles in the arithmetic Deligne cohomologyApr 09 2006In this note, we investigate the Chern classes of flat bundles in the arithmetic Deligne Cohomology, introduced by Green-Griffiths, Asakura-Saito. We show nontriviality of the Chern classes in some cases and the proof also indicates that generic flat ... More

Unifying aspects of polarization of vector mesons from hard production in DIS and at TevatronAug 08 2001Virtual photons have both the transverse and longitudinal polarization. In the inclusive DIS the impact of longitudinal photons, quantified by R=sigmaL/\igmaT sim 0.2, is marginal, but in diffractive DIS with excitation of small mass hadronic states or ... More

Stability of tangent bundle on the moduli space of stable bundles on a curveNov 01 2011Feb 12 2014In this paper, we prove that the tangent bundle of the moduli space $\cSU_C(r,d)$ of stable bundles of rank $r>2$ and of fixed determinant of degree $d$ (such that $(r,d)=1$), on a smooth projective curve $C$ is always stable, in the sense of Mumford-Takemoto. ... More

Cohomological invariants of a variation of flat connectionApr 20 2015Sep 23 2015In this paper, we apply the theory of Chern-Cheeger-Simons to construct canonical invariants associated to a $r$-simplex whose points parametrize flat connections on a smooth manifold $X$. These invariants lie in degrees $(2p-r-1)$-cohomology with $C/Z$-coefficients, ... More

Bosonic stimulation of cold 1s excitons into a harmonic potential minimum in Cu$_2$OFeb 07 2003Density distribution of cold exciton clouds generated into a strain-induced potential well by two-photon excitation in Cu$_2$O is studied at 2 K. We find that an anomalous spike, which can be interpreted as accumulation of the excitons into the ground ... More

The Universal Equation of State near the Critical Point of QCDJan 12 2004Jun 18 2004We study the universal properties of the phase diagram of QCD near the critical point using the exact renormalization group. For two-flavour QCD and zero quark masses we derive the universal equation of state in the vicinity of the tricritical point. ... More

Analytical Estimate of the Effect of Spherical Inhomogeneities on Luminosity Distance and RedshiftFeb 06 2008Jun 25 2008We provide an analytical estimate of the effect of a spherical inhomogeneity on light beams that travel through it. We model the interior of the inhomogeneity in terms of the Lemaitre-Tolman-Bondi metric. We assume that the beam source is located outside ... More

Heavy quark skyrmionsMay 18 2009The description of the heavy baryons as heavy-meson--soliton bound systems is reviewed. We outline how such bound systems arise from effective lagrangians that respect both chiral symmetry and heavy quark symmetry. Effects due to finite heavy quark masses ... More

Wind of presupernova IIn SN~1997egJan 15 2019Spectra and phototometry of type IIn supernova SN 1997eg are used to determine properties of the circumstellar gas lost by the presupernova during the latest 200 years before the explosion. The analysis of narrow H$\alpha$ and [Fe X] 6374 \AA\ results ... More

Upgrading the Local Ergodic Theorem for planar semi-dispersing billiardsMay 29 2007Jun 04 2009The Local Ergodic Theorem (also known as the `Fundamental Theorem') gives sufficient conditions under which a phase point has an open neighborhood that belongs (mod 0) to one ergodic component. This theorem is a key ingredient of many proofs of ergodicity ... More

Connection between Diffraction and Small-$x$Nov 30 2001A brief review of the modern QCD theory of diffractive DIS is given.

Diffractive DIS: Where Are We?Nov 12 2001Nov 20 2001A brief review of the modern QCD theory of diffractive DIS is given. The recent progress has been remarkably rapid, all the principal predictions from the color dipole approach to diffraction - the $(Q^2+m_V^2)$ scaling, the pattern of SCHNC, shrinkage ... More

Diffractive Vector Mesons in DIS: Meson Structure and QCDSep 15 2000I review the modern status of QCD theory of diffractive vector meson production with the focus on shrinkage of photons with Q2 and (Q2+mV2)$scaling, j-plane properties of the QCD pomeron and Regge shrinkage of diffraction cone, $s$-channel helicity non-conservation ... More

Spin dependence of diffractive DISMay 31 1999I review the recent progress in the theory of s-channel helicity nonconservation (SCHNC) effects in diffractive DIS including the unitarity driven demise of the Burkhardt-Cottingham sum rule and strong scaling departure from the Wandzura-Wilczek relation. ... More

Flow-invariant hypersurfaces in semi-dispersing billiardsMar 15 2006This work results from our attempts to solve Boltzmann-Sinai's hypothesis about the ergodicity of hard ball gases. A crucial element in the studies of the dynamics of hard balls is the analysis of special hypersurfaces in the phase space consisting of ... More

New upper bound for a class of vertex Folkman numbersJan 11 2006We improve the previuosly known bound for some vertex Folkman numbers.

On the speed and acceleration of electron beams triggering interplanetary type III radio burstsJul 24 2015Type III radio bursts are intense radio emissions triggered by beams of energetic electrons often associated with solar flares. These exciter beams propagate outwards from the Sun along an open magnetic field line in the corona and in the interplanetary ... More

Equivalence of magnetic field and particle dilution in the strange metal state of CeCoIn$_5$Oct 19 2018The Bardeen-Cooper-Schrieffer mechanism for superconductivity is a triumph of the theory of many-body systems. Implicit in its formulation is the existence of long-lived (quasi)particles, originating from the electronic building blocks of the materials, ... More

In-flight calibration of STEREO-B/WAVES antenna systemAug 26 2015The STEREO/WAVES (SWAVES) experiment on board the two STEREO spacecraft (Solar Terrestrial Relations Observatory) launched on 25 October 2006 is dedicated to the measurement of the radio spectrum at frequencies between a few kilohertz and 16 MHz. The ... More

On spectral properties and statistical analysis of Fisher-Snedecor diffusionJul 28 2010We consider the problem of parameter estimation for an ergodic diffusion with Fisher-Snedecor invariant distribution, to be called Fisher-Snedecor diffusion. We compute the spectral representation of its transition density, which involves a finite number ... More

Calibration of Advanced Virgo and Reconstruction of the Gravitational Wave Signal h(t) during the Observing Run O2Jul 09 2018Sep 03 2018In August 2017, Advanced Virgo joined Advanced LIGO for the end of the O2 run, leading to the first gravitational waves detections with the three-detector network. This paper describes the Advanced Virgo calibration and the gravitational wave strain h(t) ... More

The $ρ^{\pm}-ρ^0$ Mass Splitting ProblemJan 04 1999Jan 05 1999It is discussed the problem of the $\rho^\pm-\rho^0$ mass splitting. It is suggested to use the $\phi\to\rho\pi\to 3\pi$ decay to measure the $\rho^{\pm}-\rho^0$ mass splitting.

An Overview of STAR Experimental ResultsAug 15 2014With large acceptance and excellent particle identification, STAR is one of the best mid-rapidity collider experiments for studying high-energy nuclear collisions. The STAR experiment provides full information on initial conditions, properties of the ... More

A Particle In Cell code development for high current ion beam transport and plasma simulationsJun 20 2016A simulation package employing a Particle in Cell (PIC) method is developed to study the high current beam transport and the dynamics of plasmas. This package includes subroutines those are suited for various planned projects at University of Frankfurt. ... More

Comment on "Pygmy dipole response of proton-rich argon nuclei in random-phase approximation and no-core shell model"Mar 03 2008Sep 03 2008In a recent article by C. Barbieri, E. Caurier, K. Langanke, and G. Mart\'inez-Pinedo \cite{Bar.08}, low-energy dipole excitations were studied in proton-rich $^{32,34}$Ar with random-phase approximation (RPA) and no-core shell model (NCSM) using correlated ... More

Nilpotent, algebraic and quasi-regular elements in rings and algebrasJul 15 2015We prove that an integral Jacobson radical ring is always nil, which extends a well known result from algebras over fields to rings. As a consequence we show that if every element x of a ring R is a zero of some polynomial p_x with integer coefficients, ... More

SINGINT: Automatic numerical integration of singular integrandsOct 30 2002We explore the combination of deterministic and Monte Carlo methods to facilitate efficient automatic numerical computation of multidimensional integrals with singular integrands. Two adaptive algorithms are presented that employ recursion and are runtime ... More

A threshold-improved narrow-width approximation for BSM physicsAug 08 2007Apr 14 2008A modified narrow-width approximation that allows for O(Gamma/M)-accurate predictions for resonant particle decay with similar intermediate masses is proposed and applied to MSSM processes to demonstrate its importance for searches for particle physics ... More

QCD Sum Rules and the Determination of Leading Twist Non-Singlet Operator Matrix ElementsDec 25 1996Dec 26 1996We use QCD sum rules to determine directly the leading-twist non-singlet operator matrix elements based on calculations of three-point correlator functions in configuration space. We find a different result from that obtained by integrating the structure ... More

Are Graphene Sheets Stable?Mar 20 2007The answer to the title question is yes and the sheets exhibit diffraction peaks but may not have long range crystalline order. This is not a trivial question and answer and is immersing in the very active field now days of the study of properties of ... More

Open Descendants at c = 1May 11 2005The algebraic construction of open descendants is reviewed and extended. The procedure is applied to c=1 models. Chiral data for the case of extended free boson orbifolds is presented, in the form of fusing and brading matrices for the untwisted sector. ... More

Effect of dissipative forces on the theory of a single-atom microlaserNov 30 1998We describe a one-atom microlaser involving Poissonian input of atoms with a fixed flight time through an optical resonator. The influence of the cavity reservoir during the interactions of successive individual atoms with the cavity field is included ... More

Capacity of shrinking condensers in the planeAug 26 2011We show that the capacity of a class of plane condensers is comparable to the capacity of corresponding "dyadic condensers". As an application, we show that for plane condensers in that class the capacity blows up as the distance between the plates shrinks, ... More

Anomalous dimensions of four-quark operators in the large N_f limitOct 28 1997The anomalous dimensions of four-quark operators $(\bar q_i q_j)_{V-A} (\bar q_k q_l)_{V-A}$ are calculated in the large $N_f$ limit. As expected, the result is a convergent series without renormalon ambiguities. Using the approximation of "Naive Nonabelianization", ... More

Dive into the heart of red giant stars to better understand our GalaxyDec 16 2013The availability of asteroseismic constrains for of large sample of stars observed with CoRoT and Kepler paves the way for statistical studies of the seismic properties of stellar populations, and becomes a powerful tool to better understand stellar structure ... More

On Pauli's invention of non-abelian Kaluza-Klein Theory in 1953Dec 15 2000There are documents which show that Wolfgang Pauli developed in 1953 the first consistent generalization of the five-dimensional theory of Kaluza, Klein, Fock and others to a higher dimensional internal space. Because he saw no way to give masses to the ... More

The mystery of the cosmic vacuum energy density and the accelerated expansion of the UniverseAug 31 1999After a short history of the $\Lambda$-term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance-physics, corresponding to an energy scale of at least 100 GeV. The actual tiny value of the cosmological ... More

Comment on "Microscopic Theory of Periodic Conductances in Narrow Channels"Sep 24 1993In a recent letter Johnson and Payne (JP) have studied the effect of the electron interaction on the periodic conductance oscillations in narrow channels based on an exactly solvable model. In this Comment we discuss the exchange-correlation effect on ... More

Infrared behavior of interacting bosons at zero temperatureJun 24 2011We review the infrared behavior of interacting bosons at zero temperature. After a brief discussion of the Bogoliubov approximation and the breakdown of perturbation theory due to infrared divergences, we show how the non-perturbative renormalization ... More

Infrared behavior and spectral function of a Bose superfluid at zero temperatureJul 16 2009Oct 28 2009In a Bose superfluid, the coupling between transverse (phase) and longitudinal fluctuations leads to a divergence of the longitudinal correlation function, which is responsible for the occurrence of infrared divergences in the perturbation theory and ... More

Comment on ``Universal Spin-Flip Transition in Itinerant Antiferromagnets"May 25 2006In a recent paper [Phys. Rev. Lett. 91, 117201 (2003)], it is argued that an itinerant antiferromagnet in an external magnetic field undergoes a spin-flip transition, in marked contrast with the behavior of a localized antiferromagnet: for a weak magnetic ... More

Renormalization group approach to interacting fermion systems in the two-particle-irreducible formalismJun 21 2005Nov 11 2005We describe a new formulation of the functional renormalization group (RG) for interacting fermions within a Wilsonian momentum-shell approach. We show that the Luttinger-Ward functional is a fixed point of the RG, and derive the infinite hierarchy of ... More

Spin fluctuations and pseudogap in the two-dimensional half-filled Hubbard model at weak couplingOct 08 2001Jul 04 2002Starting from the Hubbard model in the weak-coupling limit, we derive a spin-fermion model where the collective spin excitations are described by a non-linear sigma model. This result is used to compute the fermion spectral function $A({\bf k},\omega)$ ... More