Results for "Silvia Bianchi"
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Infrared Stability of N=2 Chern-Simons Matter TheoriesDec 22 2009Feb 04 2010According to the AdS4/CFT3 correspondence, N=2 supersymmetric Chern-Simons matter theories should have a stable fixed point in the infrared. In order to support this prediction we study RG flows of two-level Chern-Simons matter theories with/without flavors ... More Circuits and circulant minorsFeb 08 2019Circulant contraction minors play a key role for characterizing ideal circular matrices in terms of minimally non ideal structures. In this article we prove necessary and sufficient conditions for a circular matrix $A$ to have circulant contraction minors ... More The Conformal Manifold of Chern-Simons Matter TheoriesSep 30 2010Oct 25 2010We determine perturbatively the conformal manifold of N=2 Chern-Simons matter theories with the aim of checking in the three dimensional case the general prescription based on global symmetry breaking, recently introduced. We discuss in details few remarkable ... More Infrared stability of ABJ-like theoriesOct 27 2009Nov 11 2009We consider marginal deformations of the superconformal ABJM/ABJ models which preserve N=2 supersymmetry. We determine perturbatively the spectrum of fixed points and study their infrared stability. We find a closed line of fixed points which is IR stable. ... More Homotopy type of symplectomorphism groups of S^2 X S^2Sep 25 2000May 02 2002In this paper we discuss the topology of the symplectomorphism group of a product of two 2-dimensional spheres when the ratio of their areas lies in the interval (1,2]. More precisely we compute the homotopy type of this symplectomorphism group and we ... More Modelling the Far-Infrared emission in spyral galaxiesNov 22 1999This thesis presents an original model for the FIR emission in spirals, developed from an existing radiative transfer code (Bianchi, Ferrara & Giovanardi, 1996, ApJ, 465, 127). The model's main features are: a complete treatment of multiple scattering ... More Black hole entropy from graviton entanglementNov 02 2012Jan 07 2013We argue that the entropy of a black hole is due to the entanglement of matter fields and gravitons across the horizon. While the entanglement entropy of the vacuum is divergent because of UV correlations, we show that low-energy perturbations of the ... More Black Hole Entropy, Loop Gravity, and Polymer PhysicsNov 25 2010Loop Gravity provides a microscopic derivation of Black Hole entropy. In this paper, I show that the microstates counted admit a semiclassical description in terms of shapes of a tessellated horizon. The counting of microstates and the computation of ... More The covariogram and Fourier-Laplace transform in $\mathbb{C}^n$Dec 30 2013Apr 29 2016The covariogram $g_{K}$ of a convex body $K$ in $\mathbb{R}^n$ is the function which associates to each $x\in\mathbb{R}^n$ the volume of the intersection of $K$ with $K+x$. Determining $K$ from the knowledge of $g_K$ is known as the Covariogram Problem. ... More Lovász-Schrijver PSD-operator on Claw-Free GraphsDec 06 2016The subject of this work is the study of $\LS_+$-perfect graphs defined as those graphs $G$ for which the stable set polytope $\stab(G)$ is achieved in one iteration of Lov\'asz-Schrijver PSD-operator $\LS_+$, applied to its edge relaxation $\estab(G)$. ... More On dominating set polyhedra of circular interval graphsDec 19 2017Feb 20 2018Clique-node and closed neighborhood matrices of circular interval graphs are circular matrices. The stable set polytope and the dominating set polytope on these graphs are therefore closely related to the set packing polytope and the set covering polyhedron ... More Light-like Wilson loops in ABJM and maximal transcendentalityApr 22 2013We revisit the computation of the two-loop light-like tetragonal Wilson loop for three dimensional pure Chern-Simons and N=6 Chern-Simons-matter theory, within dimensional regularization with dimensional reduction scheme. Our examination shows that, contrary ... More The 1/2 BPS Wilson loop in ABJM theory at two loopsMar 27 2013We compute the expectation value of the 1/2 BPS circular Wilson loop in ABJM theory at two loops in perturbation theory. The result shows perfect agreement with the prediction from localization and the proposed framing factor. The 1/2 BPS Wilson loop in ABJ(M) at two loops: The detailsJul 02 2013Jul 14 2013We compute the expectation value of the 1/2 BPS circular Wilson loop operator in ABJ(M) theory at two loops in perturbation theory. Our result turns out to be in exact agreement with the weak coupling limit of the prediction coming from localization, ... More Equilibrium points for Optimal Investment with Vintage CapitalDec 01 2007The paper concerns the study of equilibrium points, namely the stationary solutions to the closed loop equation, of an infinite dimensional and infinite horizon boundary control problem for linear partial differential equations. Sufficient conditions ... More Umbral Calculus, a Different Mathematical LanguageFeb 24 2018This thesis is intended to provide an account of the theory and applications of Operational Methods that allow the "translation" of the theory of special functions and polynomials into a "different" mathematical language. The language we are referring ... Moremath.CA05A40, 44A99, 47B99, 33C52, 33C65, 33C99, 33B10, 33B15, 33C45,
11K99, etc Ergodic convergence of a stochastic proximal point algorithmApr 21 2015Jul 25 2016The purpose of this paper is to establish the almost sure weak ergodic convergence of a sequence of iterates $(x_n)$ given by $x_{n+1} = (I+\lambda_n A(\xi_{n+1},\,.\,))^{-1}(x_n)$ where $(A(s,\,.\,):s\in E)$ is a collection of maximal monotone operators ... More Entropy of Non-Extremal Black Holes from Loop GravityApr 23 2012We compute the entropy of non-extremal black holes using the quantum dynamics of Loop Gravity. The horizon entropy is finite, scales linearly with the area A, and reproduces the Bekenstein-Hawking expression S = A/4 with the one-fourth coefficient for ... More Perturbation theory for string sigma modelsApr 06 2016Apr 07 2016In this thesis we investigate quantum aspects of the Green-Schwarz superstring in various AdS backgrounds relevant for the AdS/CFT correspondence, providing several examples of perturbative computations in the corresponding integrable sigma-models. We ... More Splitting of the homology of the punctured mapping class groupMar 14 2019Let $\Gamma_{g,1}^m$ be the mapping class group of the orientable surface $\Sigma_{g,1}^m$ of genus $g$ with one parametrised boundary curve and $m$ permutable punctures; when $m=0$ we omit it from the notation. Let $\beta_{m}(\Sigma_{g,1})$ be the braid ... More Quadratic Chabauty for (bi)elliptic curves and Kim's conjectureApr 09 2019We explore a number of problems related to the quadratic Chabauty method for determining integral points on hyperbolic curves. We remove the assumption of semistability in the description of the quadratic Chabauty sets $\mathcal{X}(\mathbb{Z}_p)_2$ containing ... More Radiative Transfer in Spiral GalaxiesSep 16 2003The internal dust extinction in spiral galaxies can affect our understanding of their structure and morphology, as well as our perception of the distant universe in the background. The intrinsic properties of the stellar and dust components can be studied ... More The covariogram determines three-dimensional convex polytopesMay 12 2008The cross covariogram g_{K,L} of two convex sets K, L in R^n is the function which associates to each x in R^n the volume of the intersection of K with L+x. The problem of determining the sets from their covariogram is relevant in stochastic geometry, ... More Modeling and Querying Data Cubes on the Semantic WebDec 18 2015The web is changing the way in which data warehouses are designed, used, and queried. With the advent of initiatives such as Open Data and Open Government, organizations want to share their multidimensional data cubes and make them available to be queried ... More Optimization Modulo Theories with Linear Rational CostsOct 22 2014In the contexts of automated reasoning (AR) and formal verification (FV), important decision problems are effectively encoded into Satisfiability Modulo Theories (SMT). In the last decade efficient SMT solvers have been developed for several theories ... More Kicked neutron stars and microlensingSep 02 1996Due to the large kick velocities with which neutron stars are born in supernovae explosions, their spatial distribution is more extended than that of their progenitor stars. The large scale height of the neutron stars above the disk plane makes them potential ... More Progress in high-energy cosmic ray physicsOct 30 2017We review some of the recent progress in our knowledge about high-energy cosmic rays, with an emphasis on the interpretation of the different observational results. We discuss the effects that are relevant to shape the cosmic ray spectrum and the explanations ... More Operators ideals and approximation propertiesNov 30 2012Dec 13 2012We use the notion of $\A$-compact sets, which are determined by a Banach operator ideal $\A$, to show that most classic results of certain approximation properties and several Banach operator ideals can be systematically studied under this framework. ... More Generic expansions of countable modelsOct 31 2010Jan 20 2012We compare two different notions of generic expansions of countable saturated structures. One kind of genericity is related to model-companions and to amalgamation constructions \'a la Hrushovski-Fra\"iss\'e. Another notion of generic expansion is defined ... More Generic Large Cardinals and Systems of FiltersNov 17 2015We introduce the notion of $\mathcal{C}$-system of filters, generalizing the standard definitions of both extenders and towers of normal ideals. This provides a framework to develop the theory of extenders and towers in a more general and concise way. ... More Summary of WG6: Spin PhysicsAug 30 2016The working group on Spin Physics at the XXIV International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2016) witnessed a significant progress in the theoretical and experimental investigations aiming at unveiling the innermost structure ... More New convergence results for the scaled gradient projection methodJun 25 2014Feb 26 2015The aim of this paper is to deepen the convergence analysis of the scaled gradient projection (SGP) method, proposed by Bonettini et al. in a recent paper for constrained smooth optimization. The main feature of SGP is the presence of a variable scaling ... More Automorphisms of trivalent graphsNov 15 2011Let $G_{g,b}$ be the set of all uni/trivalent graphs representing the combinatorial structures of pant decompositions of the oriented surface of genus $g$ with $b$ boundary components. We describe the set $A_{g,b}$ of all automorphisms of graphs in $G_{g,b}$ ... More The Blaschke-Santalo InequalityDec 01 2013Aug 04 2014The Blaschke-Santal\'o Inequality is the assertion that the volume product of a centrally symmetric convex body in Euclidean space is maximized by (and only by) ellipsoids. In this paper we give a Fourier analytic proof of this fact. A matrix model for the latitude Wilson loop in ABJM theoryFeb 21 2018Aug 13 2018In ABJ(M) theory, we propose a matrix model for the exact evaluation of BPS Wilson loops on a latitude circular contour, so providing a new weak-strong interpolation tool. Intriguingly, the matrix model turns out to be a particular case of that computing ... More One Loop Amplitudes In ABJMApr 19 2012Jul 10 2012For three dimensional N=6 superconformal field theories we compute one-loop scattering amplitudes for any number of external particles. We focus on a particular subsector of N=2 invariant superamplitudes for which the ordinary perturbative evaluation ... More Scattering Amplitudes/Wilson Loop Duality In ABJM TheoryJul 15 2011Oct 05 2011For N=6 superconformal Chern-Simons-matter theories in three dimensions, by a direct superspace Feynman diagram approach, we compute the two-loop four-point scattering amplitude with external chiral matter fields. We find that the result is in perfect ... More On p-Compact mappings and p-approximationJul 08 2011Aug 04 2011The notion of $p$-compact sets arises naturally from Grothendieck's characterization of compact sets as those contained in the convex hull of a norm null sequence. The definition, due to Sinha and Karn (2002), leads to the concepts of $p$-approximation ... More A new method to search for a cosmic ray dipole anisotropyApr 28 2005We propose a new method to determine the dipole (and quadrupole) component of a distribution of cosmic ray arrival directions, which can be applied when there is partial sky coverage and/or inhomogeneous exposure. In its simplest version it requires that ... More Generic Large Cardinals and Systems of FiltersNov 17 2015Apr 05 2017We introduce the notion of $\mathcal{C}$-system of filters, generalizing the standard definitions of both extenders and towers of normal ideals. This provides a framework to develop the theory of extenders and towers in a more general and concise way. ... More Algebraic Properties of Codimension Series of PI-AlgebrasNov 01 2011For a PI-algebra R over a field of characteristic 0 let T(R) be the T-ideal of the polynomial identities of R and let c(R,t) be the codimension series of R (i.e., the generating function of the codimension sequence of R). Let A, B and R be PI-algebras ... More Structured conditioning of Hamiltonian eigenvalue problemsMay 21 2012We discuss the effect of structure-preserving perturbations on complex or real Hamiltonian eigenproblems and characterize the structured worst-case effect perturbations. We derive significant expressions for both the structured condition numbers and the ... More The complex of pant decompositions of a surfaceOct 08 2007Oct 27 2007We exhibit a set of edges (moves) and 2-cells (relations) making the complex of pant decompositions on a surface a simply connected complex. Our construction, unlike the previous ones, keeps the arguments concerning the structural transformations independent ... More Big Data Computing and Clouds: Trends and Future DirectionsDec 17 2013Aug 22 2014This paper discusses approaches and environments for carrying out analytics on Clouds for Big Data applications. It revolves around four important areas of analytics and Big Data, namely (i) data management and supporting architectures; (ii) model development ... More Attractive forces between circular polyions of the same chargeDec 19 2001We study two models of ringlike polyions which are two-dimensional versions of simple models for colloidal particles (model A) and for rodlike segments of DNA (model B), both in solution with counterions. The counterions may condensate on Z sites of the ... More Fast nonnegative least squares through flexible Krylov subspacesNov 19 2015Jan 06 2017Constrained least squares problems arise in a variety of applications, and many iterative methods are already available to compute their solutions. This paper proposes a new efficient approach to solve nonnegative linear least squares problems. The associated ... More