Results for "C. E. Cappa"

total 192998took 0.14s
Multifrequency study of the ring nebula SG13Nov 20 2008We investigate the morphology and kinematics of the interstellar medium in the environs of the open cluster Mrk50, which includes the Wolf-Rayet star WR157 and a number of early B-type stars. The analysis was performed using radio continuum images at ... More
Sh2-205: I. The surrounding interstellar mediumFeb 15 2008Feb 20 2008We present a study of the HII region Sh2-205 and its environs, based on data obtained from the CGPS, 12CO observations, and MSX data. We find that Sh2-205 can be separated in three independent optical structures: SH 149.25-0.0, SH 148.83-0.67, and LBN ... More
Sh2-205: II. Its quiescent stellar formation activityFeb 11 2009We present a study of active stellar forming regions in the environs of the HII region Sh2-205. The analysis is based on data obtained from point source catalogues and images extracted from 2MASS, MSX, and IRAS surveys. Complementary data are taken from ... More
Large HI structures linked to southern O-type starsOct 01 2008In our search for interstellar bubbles around massive stars we analyze the environs of the O-type stars HD 38666, HD 124979, HD 163758, and HD 171589. The location of the stars, which are placed far from the galactic plane, favors the formation of large ... More
Mass loss rate determinations of southern OB starsMay 03 2001A sample of OB stars (eleven Of, one O and one B supergiant) has been surveyed with the Australia Telescope Compact Array at 4.8 and 8.64 GHz with a resolution of 2'' -- 4''. Five stars were detected; three of them have negative spectral indices, consistent ... More
Molecular gas towards G18.8+1.8Apr 17 2012This work aims at investigating the characteristics of the molecular gas associated with the nebula G18.8+1.8, linked to the Wolf-Rayet star HD168206 (WR 113), and its relation to other components of its local interstellar medium. We carried out molecular ... More
Ionized gas, molecules, and dust in Sh2-132Feb 24 2010We analyze the various interstellar components of the HII region Sh2-132. The main stellar source is the double binary system that includes the Wolf-Rayet star WR153ab. We use radio continuum images at 408 and 1420 MHz, and HI 21cm line data taken from ... More
NGC 3503 and its molecular environmentNov 16 2011We present a study of the molecular gas and interstellar dust distribution in the environs of the HII region NGC 3503 associated with the open cluster Pis 17 with the aim of investigating the spatial distribution of the molecular gas linked to the nebula ... More
Unveiling the molecular environment of the ring nebula RCW 78Oct 16 2009We present a study of the ionized, neutral atomic, and molecular gas associated with the ring nebula RCW 78 around the WR star HD 117688 (= WR 55). We based our study on CO observations carried out with the SEST and NANTEN telescopes. We report the detection ... More
Unveiling the birth and evolution of the HII region Sh2-173Dec 19 2008Based on a multiwavelength study, the ISM around the HII region Sh2-173 has been analyzed. The ionized region is clearly detected in the optical and in the radio continuum images. The analysis of the HI data shows a region of low emissivity that has an ... More
Molecular gas associated with IRAS 10361-5830Jul 03 2014We analyze the distribution of the molecular gas and the dust in the molecular clump linked to IRAS 10361-5830, located in the environs of the bubble-shaped HII region Gum 31 in the Carina region, with the aim of determining the main parameters of the ... More
Molecules, dust, and protostars in NGC 3503Feb 20 2014We are presenting here a follow-up study of the molecular gas and dust in the environs of the star forming region NGC 3503. This study aims at dealing with the interaction of NGC 3503 with its parental molecular cloud, and also with the star formation ... More
The IRAS 08589-4714 star-forming regionSep 04 2016We present an analysis of the IRAS 08589-4714 star-forming region. This region harbors candidate young stellar objects identified in the WISE and Herschel images using color index criteria and spectral energy distributions (SEDs). The SEDs of some of ... More
Star forming regions linked to RCW78 and the discovery of a new IR bubbleOct 31 2013With the aim of investigating the presence of molecular and dust clumps linked to two star forming regions identified in the expanding molecular envelope of the stellar wind bubble RCW78, we analyzed the distribution of the molecular gas and cold dust. ... More
Molecular gas in the star-forming region IRAS 08589-4714Sep 05 2016We present an analysis of the region IRAS 08589-4714 with the aim of characterizing the molecular environment. We observed the CO(3-2), ^{13}CO(3-2), C^{18}O(3-2), HCO+(3-2), and HCN(3-2) molecular lines in a region of 150" x 150", centered on the IRAS ... More
Molecular gas and star formation towards the IR dust bubble S24 and its environsSep 11 2015We present a multi-wavelength analysis of the infrared dust bubble S24, and its environs, with the aim of investigating the characteristics of the molecular gas and the interstellar dust linked to them, and analyzing the evolutionary status of the young ... More
870 micron continuum observations of the bubble-shaped nebula Gum 31Jun 26 2015Jun 29 2015We are presenting here a study of the cold dust in the infrared ring nebula Gum 31. We aim at deriving the physical properties of the molecular gas and dust associated with the nebula, and investigating its correlation with the star formation in the region, ... More
A multifrequency study of the active star forming complex NGC6357. I. Interstellar structures linked to the open cluster Pis24Apr 13 2011We investigate the distribution of the gas (ionized, neutral atomic and molecular), and interstellar dust in the complex star forming region NGC6357 with the goal of studying the interplay between the massive stars in the open cluster Pis24 and the surrounding ... More
Millimeter and far-IR study of the IRCD SDC 341.232-0.268Jul 10 2019We analyze the molecular gas and dust associated with the infrared dark cloud SDC 341.232-0.268 in order to investigate the characteristics and parameters of the gas, determine the evolutionary status of four embedded EGO candidates and establish possible ... More
An HI interstellar bubble surrounding WR85 and RCW118Jul 20 2005We analyze the distribution of the interstellar matter in the environs of the Wolf-Rayet star LSS3982 (= WR85, WN6+OB?) linked to the optical ring nebula RCW118. Our study is based on neutral hydrogen 21cm-line data belonging to the Southern Galactic ... More
A submillimeter study of the IR dust bubble S 21 and its environsNov 08 2016Based on the molecular emission in the $^{12}$CO(2-1) and $^{13}$CO(2-1) lines, and the continuum emission in the MIR and FIR towards the S21 IR dust bubble, we analyze the physical characteristics of the gas and dust linked to the nebula and the presence ... More
The radio and IR counterparts of the ring nebula around HD211564Dec 04 2009We report the detection of the radio and infrared counterparts of the ring nebula around the WN3(h) star HD211564 (WR152), located to the southwest of the HII region Sh2132. Using radio continuum data from the Canadian Galactic Plane Survey, we identified ... More
A Very Large Array 3.6cm continuum survey of Galactic Wolf-Rayet starsJan 27 2004We report the results of a survey of radio continuum emission of Galactic Wolf-Rayet stars north of declination -46 degrees. The observations were obtained at 8.46 GHz (3.6cm) using the Very Large Array (VLA), with an angular resolution of about 6 x 9 ... More
The environs of the HII region Gum31Nov 15 2007We analyze the distribution of the interstellar matter in the environs of the HII region Gum31, excited by the open cluster NGC3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surrounding ... More
The environs of the HII region Gum31Jul 13 2007We analyze the distribution of the interstellar matter in the environs of the \hii region Gum 31, excited by the open cluster NGC 3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surrounding ... More
On the Ornstein-Uhlenbeck operator in convex sets of Banach spacesMar 10 2015Jun 22 2016We study the Ornstein-Uhlenbeck operator and the Ornstein-Uhlenbeck semigroup in an open convex subset of an infinite dimensional separable Banach space $X$. This is done by finite dimensional approximation. In particular we prove Logarithmic-Sobolev ... More
Maximal $L^2$ regularity for Ornstein-Uhlenbeck equation in convex sets of Banach spacesOct 22 2015We study the elliptic equation $\lambda u-L^{\Omega}u=f$ in an open convex subset $\Omega$ of an infinite dimensional separable Banach space $X$ endowed with a centered non-degenerate Gaussian measure $\gamma$, where $L^\Omega$ is the Ornstein-Uhlenbeck ... More
On the Ornstein-Uhlenbeck operator in convex sets of Banach spacesMar 10 2015Sep 11 2017We study the Ornstein-Uhlenbeck operator and the Ornstein-Uhlenbeck semigroup in an open convex subset of an infinite dimensional separable Banach space $X$. This is done by finite dimensional approximation. In particular we prove Logarithmic-Sobolev ... More
Clumpy molecular structures revolving the B[e] supergiant MWC 137Oct 17 2016The peculiar emission-line star MWC 137 with its extended optical nebula was recently classified as B[e] supergiant. To study the spatial distribution of its circumstellar molecular gas on small and large scales, we obtained near-infrared and radio observations ... More
Maximal Sobolev regularity for solutions of elliptic equations in Banach spaces endowed with a weighted Gaussian measure: the convex subset caseSep 23 2016Nov 07 2016Let $X$ be a separable Banach space endowed with a non-degenerate centered Gaussian measure $\mu$. The associated Cameron--Martin space is denoted by $H$. Consider two sufficiently regular convex functions $U:X\rightarrow\mathbb{R}$ and $G:X\rightarrow ... More
Maximal Sobolev regularity for solutions of elliptic equations in infinite dimensional Banach spaces endowed with a weighted Gaussian measureMar 31 2016Aug 29 2016Let $X$ be a separable Banach space endowed with a non-degenerate centered Gaussian measure $\mu$. The associated Cameron-Martin space is denoted by $H$. Let $\nu=e^{-U}\mu$, where $e^{-U}$ is a sufficiently regular weight and $U:X\rightarrow\mathbb{R}$ ... More
Maximal Sobolev regularity for solutions of elliptic equations in Banach spaces endowed with a weighted Gaussian measure: the convex subset caseSep 23 2016Let $X$ be a separable Banach space endowed with a non-degenerate centered Gaussian measure $\mu$. The associated Cameron--Martin space is denoted by $H$. Consider two sufficiently regular convex functions $U:X\rightarrow\mathbb{R}$ and $G:X\rightarrow ... More
Non radial solutions for non homogeneous Hénon equationApr 03 2014In this paper we study a H\'enon-like equation (see equations (1) below), where the nonlinearity f(t) is not homogeneous (i.e., it is not a power). By minimization on the Nehari manifold, we prove that for large values of the parameter $\alpha$ there ... More
On the domain of elliptic operators defined in subsets of Wiener spacesJun 15 2017Jul 26 2017Let $X$ be a separable Banach space endowed with a non-degenerate centered Gaussian measure $\mu$. The associated Cameron-Martin space is denoted by $H$. Consider two sufficiently regular convex functions $U:X\rightarrow\mathbb{R}$ and $G:X\rightarrow ... More
Resolving the circumstellar environment of the Galactic B[e] supergiant star MWC 137 from large to small scalesSep 19 2017The Galactic object MWC 137 was suggested to belong to the group of B[e] supergiants. However, with its large-scale optical bipolar ring nebula and the high velocity jet and knots, it is a rather atypical representative of this class. We performed multi-wavelength ... More
Fundamental domains of cluster categories inside module categoriesDec 26 2011Let $H$ be a finite dimensional hereditary algebra over an algebraically closed field, and let $\mathcal{C}_{H}$ be the corresponding cluster category. We give a description of the (standard) fundamental domain of $\mathcal{C}_{H} $ in the bounded derived ... More
Detection of the Cherenkov light diffused by Sea Water with the ULTRA ExperimentJul 30 2007The study of Ultra High Energy Cosmic Rays represents one of the most challenging topic in the Cosmic Rays and in the Astroparticle Physics fields. The interaction of primary particles with atmospheric nuclei produces a huge Extensive Air Shower together ... More
Results from the ULTRA experiment in the framework of the EUSO projectFeb 07 2006The detection of Cerenkov light from EAS in a delayed coincidence with fluorescence light gives a strong signature to discriminate protons and neutrinos in cosmic rays. For this purpose, the ULTRA experiment has been designed with 2 detectors: a small ... More
Long-term monitoring of the TeV emission from Mrk 421 with the ARGO-YBJ experimentJun 05 2011ARGO-YBJ is an air shower detector array with a fully covered layer of resistive plate chambers. It is operated with a high duty cycle and a large field of view. It continuously monitors the northern sky at energies above 0.3 TeV. In this paper, we report ... More
Mean Interplanetary Magnetic Field Measurement Using the ARGO-YBJ ExperimentJan 22 2011The sun blocks cosmic ray particles from outside the solar system, forming a detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ experiment in Tibet. Because the cosmic ray particles are positive charged, the magnetic field between ... More
The Use of Domination Number of a Random Proximity Catch Digraph for Testing Spatial Patterns of Segregation and AssociationFeb 05 2008Priebe et al. (2001) introduced the class cover catch digraphs and computed the distribution of the domination number of such digraphs for one dimensional data. In higher dimensions these calculations are extremely difficult due to the geometry of the ... More
On the Distribution of the Domination Number of a New Family of Parametrized Random DigraphsFeb 05 2008We derive the asymptotic distribution of the domination number of a new family of random digraph called proximity catch digraph (PCD), which has application to statistical testing of spatial point patterns and to pattern recognition. The PCD we use is ... More
U-Duality of Born-Infeld on the Noncommutative Two-TorusOct 15 1998Oct 29 1998We discuss Born-Infeld on the noncommutative two-torus as a description of compactified string theory. We show that the resulting theory, including the fluctuations, is manifestly invariant under the T-duality group SO(2,2;Z). The BPS mass even has a ... More
Rationale for a Correlated Worldline Theory of Quantum GravityJun 16 2015It is argued that gravity should cause a breakdown of quantum mechanics, at low energies, accessible to table-top experiments. It is then shown that one can formulate a theory of quantum gravity in which gravitational correlations exist between worldline ... More
Yangians and W-algebrasMay 17 2013We present a connection between W-algebras and Yangians, in the case of gl(N) algebras, as well as for twisted Yangians and/or super-Yangians. This connection allows to construct an R-matrix for the W-algebras, and to classify their finite-dimensional ... More
New Five Dimensional Black Holes Classified by Horizon Geometry, and a Bianchi VI BraneworldNov 07 2000Jan 31 2001We introduce two new families of solutions to the vacuum Einstein equations with negative cosmological constant in 5 dimensions. These solutions are static black holes whose horizons are modelled on the 3-geometries nilgeometry and solvegeometry. Thus ... More
On the Algebraic Structure of the Holomorphic Anomaly for N=2 Topological StringsMay 10 1994May 14 1994The special geometry ($(t,{\bar t})$-equations) for twisted $N=2$ strings are derived as consistency conditions of a new contact term algebra. The dilaton appears in the contact terms of topological and antitopological operators. The holomorphic anomaly, ... More
Topology and Strings: Topics in $N=2$Nov 08 1994A review on topological strings and the geometry of the space of two dimensional theories. (Lectures given by C. Gomez at the Enrico Fermi Summer School, Varenna, July 1994)
Particle Physics in the Sky and Astrophysics Underground: Connecting the Universe's Largest and Smallest ScalesAug 01 2008Particles have tremendous potential as astronomical messengers, and conversely, studying the universe as a whole also teaches us about particle physics. This thesis encompasses both of these research directions. Many models predict a diffuse flux of high ... More
On the Soft Supersymmetry Breaking Parameters in Gauge-Mediated ModelsJan 21 1998Gauge mediation of supersymmetry breaking in the observable sector is an attractive idea, which naturally alleviates the flavour changing neutral current problem of supersymmetric theories. Quite generally, however, the number and quantum number of the ... More
Unification of Couplings and the Dynamical Breakdown of the Electroweak SymmetryMay 06 1993I discuss the properties of the minimal supersymmetric extension of the standard model, in the case in which there is a dynamical breakdown of the electroweak symmetry induced by the formation of condensates of the third generation of quarks and their ... More
Normed convergence property for hypergroups admitting an invariant measureJan 07 2003We prove that a hypergroup admitting a countable basis and an invariant Haar measure has normed convergence property if and only if it is compact.
Absolute continuity of autophage measures on finite-dimensional vector spacesDec 19 2002We consider a class of measures called autophage which was introduced and studied by Szekely for measures on the real line. We show that the autophage measures on finite-dimensional vector spaces over real or p-adic field are infinitely divisible without ... More
Continuous interfaces with disorder: Even strong pinning is too weak in 2 dimensionsApr 04 2007We consider statistical mechanics models of continuous height effective interfaces in the presence of a delta-pinning at height zero. There is a detailed mathematical understanding of the depinning transition in 2 dimensions without disorder. Then the ... More
Quaternionic Second-Order Freeness and the Fluctuations of Large Symplectically Invariant Random MatricesApr 17 2015We present a definition for second-order freeness in the quaternionic case. We demonstrate that this definition on a second-order probability space is asymptotically satisfied by independent symplectically invariant quaternionic matrices. This definition ... More
Distal actions and ergodic actions on compact groupsApr 30 2007Let $K$ be a compact metrizable group and $\Ga$ be a group of automorphisms of $K$. We first show that each $\ap \in \Ga$ is distal on $K$ implies $\Ga$ itself is distal on $K$, a local to global correspondence provided $\Ga$ is a generalized $\ov{FC}$-group ... More
Operator semi-selfdecomposable measures and related nested subclasses of measures on vector spacesDec 24 2002Jun 19 2003$T$-semi-selfdecomposability and subclasses $L_m(b, Q)$ and $\tilde L_m(b, Q)$ of measures on complete separable metric vector spaces are introduced and basic properties are proved. In particular, we show that $\mu$ is $T$-semi-selfdecomposable if and ... More
Twisted superYangians and their representationsNov 29 2001Starting with the superYangian Y(M|N) based on gl(M|N), we define twisted superYangians Y^+(M|N) and Y^-(M|N). Only Y^+(M|2n) and Y^-(2m|N) can be defined, and appear to be isomorphic one with each other. We study their finite-dimensional irreducible ... More
The mechanism of spin and charge separation in one dimensional quantum antiferromagnetsMay 23 1994We reconsider the problem of separation of spin and charge in one dimensional quantum antiferromagnets. We show that spin and charge separation in one dimensional strongly correlated systems cannot be described by the slave boson or fermion representation ... More
Gauge Bundles and Born-Infeld on the Noncommutative TorusOct 27 1998Oct 29 1998In this paper, we describe non-abelian gauge bundles with magnetic and electric fluxes on higher dimensional noncommutative tori. We give an explicit construction of a large class of bundles with nonzero magnetic 't Hooft fluxes. We discuss Morita equivalence ... More
Interface free energy or surface tension: definition and basic propertiesNov 27 2009Interface free energy is the contribution to the free energy of a system due to the presence of an interface separating two coexisting phases at equilibrium. It is also called surface tension. The content of the paper is 1) the definition of the interface ... More
Holography and the C-TheoremSep 26 2000We review the geometric definition of C-function in the context of field theories that admit a holographic gravity dual.
The Holographic Principle and the Renormalization GroupOct 14 1998We prove a c-theorem for holographic theories.
The IGEX experiment revisited: a response to the critique of Klapdor-Kleingrothaus,Dietz, and KrivosheinaApr 27 2004May 03 2004This paper is a response to the article "Critical View to" the IGEX neutrinoless double-beta decay experiment..."published in Phys. Rev.D, Volume 65 (2002) 092007," by H.V.Klapdor-Kleingrothaus, A. Dietz, and I.V.Krivosheina, published as preprint hep-ph/0403056. ... More
Remarks and improvement regarding the theorem of continuous dependence of solutions of F.D.E., using some new results for continuous convergencesMar 29 2017We improve the theorem on continuous dependence of solutions of functional differential equations (see J. Hale, Functional differential equations, theorem 5.1), using some new results on continuous convergences. Namely, we prove this theorem without the ... More
New boundary conditions for (extended) $\mathrm{AdS}_3$ supergravityDec 06 2018Feb 04 2019In this work, we build the most general boundary conditions for $\mathcal N=\left(1,1\right)$ and $\mathcal N=\left(2,2\right)$ extended supergravity. We show that for the loosest set of boundary conditions, their asymptotic symmetry algebras are two ... More
Ideal-Modified Bosonic Gas Trapped in an Arbitrary Three Dimensional Power-Law PotentialFeb 16 2012Oct 22 2012We analyze the effects caused by an anomalous single-particle dispersion relation suggested in several quantum-gravity models, upon the thermodynamics of a Bose-Einstein condensate trapped in a generic 3-dimensional power-law potential. We prove that ... More
Krengel-Lin decomposition for probability measures on hypergroupsDec 20 2002A Markov operator $P$ on a $\sigma$-finite measure space $(X, \Sigma, m)$ with invariant measure $m$ is said to have Krengel-Lin decomposition if $L^2 (X) = E_0 \oplus L^2 (X,\Sigma_d)$ where $E_0 = \{f \in L^2 (X) \mid ||P^n (f) || \ra 0 \}$ and $\Sigma_d$ ... More
Counting faces of cubical spheres modulo twoNov 12 1998Several recent papers have addressed the problem of characterizing the $f$-vectors of cubical polytopes. This is largely motivated by the complete characterization of the $f$-vectors of simplicial polytopes given by Stanley, Billera, and Lee in 1980. ... More
Methods for improving open cluster fundamental parameters applied to M 52 and NGC 3960Aug 01 2006We derive accurate parameters related to the CMD, structure and dynamical state of M52 and NGC3960, whose fields are affected by differential reddening. Compared to open clusters in different dynamical states studied with similar methods, the core and ... More
On heredity of strongly proximal actionsMar 28 2003We prove that action of a semigroup T on compact metric space X by continuous selfmaps is strongly proximal if and only if T action on P(X), the space of probability measures on $X$ with weak topology, is strongly proximal. As a consequence we prove that ... More
Extinction for two parabolic stochastic PDE's on the latticeMar 16 1999Dec 31 2001It is well known that, starting with finite mass, the super-Brownian motion dies out in finite time. The goal of this article is to show that with some additional work, one can prove finite time die-out for two types of systems of stochastic differential ... More
The index of biharmonic maps in spheresMar 13 2003Biharmonic maps are the critical points of the bienergy functional and generalise harmonic maps. We investigate the index of a class of biharmonic maps, derived from minimal Riemannian immersions into spheres. This study is motivated by three families ... More
Numerical study of linear and circular model DNA chains confined in a slit: metric and topological propertiesApr 09 2012Advanced Monte Carlo simulations are used to study the effect of nano-slit confinement on metric and topological properties of model DNA chains. We consider both linear and circularised chains with contour lengths in the 1.2--4.8 $\mu$m range and slits ... More
The angular momentum controversy: What's it all about and does it matter?Sep 17 2013The general question, crucial to an understanding of the internal structure of the nucleon, of how to split the total angular momentum of a photon or gluon into spin and orbital contributions is one of the most important and interesting challenges faced ... More
W-superalgebras as truncation of super-YangiansSep 25 2002We show that some finite W-superalgebras based on gl(M|N) are truncation of the super-Yangian Y(gl(M|N)). In the same way, we prove that finite W-superalgebras based on osp(M|2n) are truncation of the twisted super-Yangians Y(gl(M|2n))^{+}. Using this ... More
RTT presentation of finite W-algebrasMay 11 2000May 23 2000We construct a wide class of finite W-algebras as truncations of Yangians. These truncations correspond to algebra homomorphisms and allow to construct the W-algebras as exchange algebras, the R-matrix being the Yangian's one. As an application, we classify ... More
Linear Form of 3-scale Relativity Algebra and the Relevance of StabilityJul 11 2004We show that the algebra of the recently proposed Triply Special Relativity can be brought to a linear (ie, Lie) form by a correct identification of its generators. The resulting Lie algebra is the stable form proposed by Vilela Mendes a decade ago, itself ... More
Non-Critical Confining Strings and the Renormalization GroupFeb 01 1999Mar 01 1999String vacua for non critical strings satisfying the requirements of Zig-Zag invariance are constructed. The Liouville mode is shown to play the r\^ole of scale in the Renormalization Group operation. Differences and similarities with the D-brane near ... More
Generalised row and column removal phenomena and $p$-Kostka numbersFeb 18 2016Feb 24 2016We explain and generalise row-removal phenomena for Schur algebras via isomorphisms between subquotients of these algebras. In particular, we prove a new reduction formulae for $p$-Kostka numbers and extension groups between Weyl and simple modules.
Four-dimensional M-theory and supersymmetry breakingApr 24 1997We investigate compactifications of M-theory from $11\to 5\to 4$ dimensions and discuss geometrical properties of 4-d moduli fields related to the structure of 5-d theory. We study supersymmetry breaking by compactification of the fifth dimension and ... More
Physics at LEP and Yukawa Coupling UnificationOct 18 1995We discuss the impact of the recent precision measurements at LEP on the minimal supersymmetric standard model. We show that the values of $\tan\beta$ necessary to induce large positive corrections to $R_b$ are the same as the ones preferred by the unification ... More
Ad~$(G)$ is of type $R$ implies $G$ is of type $R$ for certain $p$-adic Lie groupsJul 09 2014We provide a sufficient condition for a $p$-adic Lie group to be of type $R$ when its adjoint image is of type $R$.
Stability of travelling-wave solutions for reaction-diffusion-convection systemsDec 19 2000We are concerned with the asymptotic behaviour of classical solutions of systems of the form u_t = Au_xx + f(u, u_x), x in R, t>0, u(x,t) a vector in RN, with u(x,0)= U(x), where A is a positive-definite diagonal matrix and f is a 'bistable' nonlinearity ... More
Are the red halos of galaxies made of low-mass stars? Constraints from subdwarf star counts in the Milky Way haloSep 17 2008Surface photometry detections of red and exceedingly faint halos around galaxies have resurrected the old question of whether some non-negligible fraction of the missing baryons of the Universe could be hiding in the form of faint, hydrogen-burning stars. ... More
Biharmonic surfaces of constant mean curvatureMay 30 2013We compute a Simons' type formula for the stress-energy tensor of biharmonic maps from surfaces. Specializing to Riemannian immersions, we prove several rigidity results for biharmonic CMC surfaces, putting in evidence the influence of the Gaussian curvature ... More
Strong relative property $(T)$ and spectral gap of random walksNov 22 2011We consider strong relative property $(T)$ for pairs $(\Ga, G)$ where $\Ga$ acts on $G$. If $N$ is a connected Lie group and $\Ga$ is a group of automorphisms of $N$, we choose a finite index subgroup $\Ga ^0$ of $\Ga$ and obtain that $(\Ga, [\Ga ^0, ... More
No representation of Moore groups and affine groups has any rate of random mixingFeb 16 2005A sequence $a_n\da 0$ forms a rate of random mixing for a unitary system $(G,\mu, \pi, {\cal H})$ if for any $u, v\in {\cal H}$ $$\limsup {|<\pi (g_n^\omega)u, v>|\over a_n} < \infty$$ a.e. $\omega$ in the probability space $(G^{\mathbb N}, \mu ^{\mathbb ... More
Some properties of second order theta functions on Prym varietiesApr 01 1999Sep 09 1999Let $P \cup P'$ be the two component Prym variety associated to an \'etale double cover $\tilde{C} \to C$ of a non-hyperelliptic curve of genus $g \geq 6$ and let $|2\Xi_0|$ and $|2\Xi_0'|$ be the linear systems of second order theta divisors on $P$ and ... More
The magnetic and electronic properties of Oxyselenides - influence of transition metal ions and lanthanidesApr 05 2017Magnetic oxyselenides have been the topic of research for several decades being first of interest in the context of photoconductivity and thermoelectricity owing to their intrinsic semiconducting properties and ability to tune the energy gap through metal ... More
Kubo-Greenwood approach to conductivity in dense plasmas with average atom modelsMar 22 2016A new formulation of the Kubo-Greenwood conductivity for average atom models is given. The new formulation improves upon previous by explicitly including the ionic-structure factor. Calculations based on this new expression lead to much improved agreement ... More
Knotting of linear DNA in nano-slits and nano-channels: a numerical studyFeb 14 2013The amount and type of self-entanglement of DNA filaments is significantly affected by spatial confinement, which is ubiquitous in biological systems. Motivated by recent advancements in single DNA molecule experiments based on nanofluidic devices, and ... More
A correction to the hydrodynamic limit of boundary driven exclusion processes in a super-diffusive time scaleSep 18 2015We consider a one-dimensional, weakly asymmetric, boundary driven exclusion process on the interval $[0,N]\cap Z$ in the super-diffusive time scale $N^2 \epsilon^{-1}_N$, where $1\ll \epsilon^{-1}_N \ll N^{1/4}$. We assume that the external field and ... More
The dielectric behavior of the living cell suspensionsNov 16 1998In the limit of small concentrations and weak applied electric fields, the dielectric permittivity of suspensions of arbitrarily shaped, shelled and charged particles is calculated. It is proved that the dielectric behavior at low frequencies is dominated ... More
Non parametric reconstruction of distribution functions from observed galactic disksAug 19 1998A general inversion technique for the recovery of the underlying distribution function for observed galactic disks is presented and illustrated. Under the assumption that these disks are axi-symmetric and thin, the proposed method yields the unique distribution ... More
Generalized Quantum Relativistic Kinematics: a Stability Point of ViewOct 20 2004We apply Lie algebra deformation theory to the problem of identifying the stable form of the quantum relativistic kinematical algebra. As a warm up, given Galileo's conception of spacetime as input, some modest computer code we wrote zeroes in on the ... More
On the Size of Structures in the Solar CoronaOct 06 2006Feb 22 2007Fine-scale structure in the corona appears not to be well resolved by current imaging instruments. Assuming this to be true offers a simple geometric explanation for several current puzzles in coronal physics, including: the apparent uniform cross-section ... More
An improved time-dependent Hartree-Fock approach for scalar φ^4 QFTJan 18 2000The $\lambda \phi^4$ model in a finite volume is studied within a non-gaussian Hartree-Fock approximation (tdHF) both at equilibrium and out of equilibrium, with particular attention to the structure of the ground state and of certain dynamical features ... More
Out-of-equilibrium dynamics of large-N φ^4 QFT in finite volumeJan 18 2000The $\lambda \phi^4$ model in a finite volume is studied in the infinite $N$ limit both at equilibrium and out of equilibrium, with particular attention to certain fundamental features of the broken symmetry phase. The numerical solution of the dynamical ... More
The O(infty) nonlinear sigma model out of equilibriumJun 21 2000Nov 22 2000The out-of-equilibrium dynamics of the O(N+1) nonlinear sigma model in 1+1 dimensions is investigated in the large N limit. Regarding the nonlinearity as the effect of a suitable large coupling limit of the O(N+1) \phi^4 model, we first of all verify ... More