Results for "Roberto Maoli"
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Improving lensing cluster mass estimate with flexionJul 20 2016Gravitational lensing has long been considered as a valuable tool to determine the total mass of galaxy clusters. The shear profile as inferred from the statistics of ellipticity of background galaxies allows to probe the cluster intermediate and outer ... More Superconformal Vacua in N=2 Usp(4) Gauge TheoriesFeb 26 2004We study the dynamics of a confining vacuum in N=2 USp(4) gauge theory with n_f=4. The vacuum appears to be a deformed conformal theory with nonabelian gauge symmetry. The low-energy degrees of freedom consist of four nonabelian magnetic monopole doublets ... More Anisotropic generalizations of de Sitter spacetimeApr 24 2002It is known that de Sitter spacetime can be seen as the solution of field equation for completely isotropic matter. In the present paper a new class of exact solutions in spherical symmetry is found and discussed, such that the energy--momentum tensor ... More Effective lagrangians for QCD at high densityAug 27 2001We describe low energy physics in the CFL and LOFF phases by means of effective lagrangians. In the CFL case we present also how to derive expressions for the parameters appearing in the lagrangian via weak coupling calculations taking advantage of the ... More Precision measurements at a muon colliderMay 10 2001This contribution describes precision width measurements that could be done at a muon collider for very narrow resonances as the Higgs or a possible pseudogoldstone boson, or for almost degenerate resonances as the A0 and H0 in the MSSM for large values ... More A Theory of algebraic integrationSep 03 1998In this paper we study the problem of quantizing theories defined over a nonclassical configuration space. If one follows the path-integral approach, the first problem one is faced with is the one of definition of the integral over such spaces. We consider ... More QCD critical point: a historical perspectiveOct 14 2006We review the history of the critical point in the QCD phase diagram, baryon density vs. temperature. In particular we discuss the different theoretical approaches to this problem. A theory of algebraic integrationDec 17 2001In this paper we extend the idea of integration to generic algebras. In particular we concentrate over a class of algebras, that we will call self-conjugated, having the property of possessing equivalent right and left multiplication algebras. In this ... More The dinner table problem: the rectangular caseJul 14 2005$n$ people are seated randomly at a rectangular table with $\lfloor n/2\rfloor$ and $\lceil n/2\rceil$ seats along the two opposite sides for two dinners. What's the probability that neighbors at the first dinner are no more neighbors at the second one? ... More Macroscopic quantum vacuum and microscopic gravitationJan 07 2011Macroscopic quantum vacuum and modern theories of gravitation share the strong interplay between geometry and physical phenomena. We review selected issues related to the accuracy of the measurement of Casimir forces with particular emphasis on the implications ... More Forecasting the Bayes factor of a future observationMar 05 2007May 09 2007I present a new procedure to forecast the Bayes factor of a future observation by computing the Predictive Posterior Odds Distribution (PPOD). This can assess the power of future experiments to answer model selection questions and the probability of the ... More The cosmological constant and the paradigm of adiabaticityApr 29 2003We discuss the value of the cosmological constant as recovered from CMB and LSS data and the robustness of the results when general isocurvature initial conditions are allowed for, as opposed to purely adiabatic perturbations. The Bayesian and frequentist ... More Uniform propagation of chaos for Kac's 1D particle systemJun 20 2016In this paper we study Kac's 1D particle system, consisting of the velocities of $N$ particles colliding at constant rate and randomly exchanging energies. We prove uniform (in time) propagation of chaos in Wasserstein distance with explicit polynomial ... More Anyon Mean Field as an Exact Limit of a Gauge TheoryFeb 04 1993We summarize a study of an Abelian gauge theory in 2+1 dimensions, the gauge field being coupled to nonrelativistic Fermions. The Action for the gauge field is a combination of the Maxwell term and a Chern-Simons (CS) term. We study the limit of vanishing ... More Anisotropy in the cosmic radiation at TeV energyFeb 28 2013In recent years very important results were obtained from cosmic ray experiments about the arrival direction distribution of primaries in the TeV energy range. As most of these particles are charged nuclei, they are deflected by the magnetic field they ... More Supercongruences for a truncated hypergeometric seriesJul 22 2010May 23 2011The purpose of this note is to obtain some congruences modulo a power of a prime $p$ involving the truncated hypergeometric series $$\sum_{k=1}^{p-1} {(x)_k(1-x)_k\over (1)_k^2}\cdot{1\over k^a}$$ for $a=1$ and $a=2$. In the last section, the special ... More Positive Operator Valued Measures and Feller Markov KernelsOct 09 2015A Positive Operator Valued Measure (POVM) is a map $F:\mathcal{B}(X)\to\mathcal{L}_s^+(\mathcal{H})$ from the Borel $\sigma$-algebra of a topological space $X$ to the space of positive self-adjoint operators on a Hilbert space $\mathcal{H}$. We assume ... More Decompositions of singular abelian surfacesAug 09 2015Feb 17 2016Given an abelian surface, the number of its distinct decompositions into a product of elliptic curves has been described by Ma. Moreover, Ma himself classified the possible decompositions for abelian surfaces of Picard number $1 \leq \rho \leq 3$. We ... More On the topological conjugacy problem for interval mapsNov 12 2014We propose an inverse approach for dealing with interval maps based on the manner whereby their branches are related (folding property), instead of addressing the map equations as a whole. As a main result, we provide a symmetry-breaking framework for ... More Ultra High Energy Cosmic Rays and NeutrinosMar 18 2016We discuss the production of ultra high energy neutrinos coming from the propagation of ultra high energy cosmic rays and in the framework of top-down models for the production of these extremely energetic particles. We show the importance of the detection ... More Joint measurability through Naimark's theoremApr 05 2014Oct 09 2015We use Naimark's dilation theorem in order to characterize the joint measurability of two POVMs. Then, we analyze the joint measurability of two commutative POVMs $F_1$ and $F_2$ which are the smearing of two self-adjoint operators $A_1$ and $A_2$ respectively. ... More Commensurability of hyperbolic manifolds with geodesic boundaryFeb 10 2005Suppose n>2, let M,M' be n-dimensional connected complete finite-volume hyperbolic manifolds with non-empty geodesic boundary, and suppose that the fundamental group of M is quasi-isometric to the fundamental group of M' (with respect to the word metric). ... More On surfaces with a canonical pencilSep 03 2009Oct 27 2010We classify the minimal surfaces of general type with $K^2 \leq 4\chi-8$ whose canonical map is composed with a pencil, up to a finite number of families. More precisely we prove that there is exactly one irreducible family for each value of $\chi \gg ... More Conformal Subnets and Intermediate SubfactorsFeb 26 2001Mar 05 2002Given an irreducible local conformal net A of von Neumann algebras on the circle and a finite-index conformal subnet B of A, we show that A is completely rational iff B is completely rational. In particular this extends a result of F. Xu for the orbifold ... More Critical cones of characteristic varietiesAug 02 2010Jun 01 2011We show that certain characteristic varieties of a finitely generated module over a given Weyl algebra arising from weighted degree filtrations are equal to the critical cone of some other characteristic varieties. This behaviour of the characteristic ... More Balanced metrics on homogeneous vector bundlesJan 16 2011Let $E\rightarrow M$ be a holomorphic vector bundle over a compact Kaehler manifold $(M, \omega)$ and let $E=E_1\oplus... \oplus E_m\rightarrow M$ be its decomposition into irreducible factors. Suppose that each $E_j$ admits a $\omega$-balanced metric ... More Uniqueness of Eigenforms on Fractals-IIJan 27 2014Mar 31 2014I give an explicitly verifiable necessary and sufficient condition for the uniqueness of the eigenform on finitely ramified fractals, once an eigenform is known. This improves the results of my previous paper [14], where I gave some necessary and some ... More Fixed Points of anti-attracting maps and Eigenforms on FractalsJan 08 2018An important problem in analysis on fractals is the existence of a self-similar energy on finitely ramified fractals. The self-similar energies are constructed in terms of eigenforms, that is, eigenvectors of a special nonlinear operator. Previous results ... More Majorana and the Infinite Component Wave EquationsOct 23 2006I review the paper of Majorana about relativistic particles with arbitrary spin written in 1932. The main motivation for this papers was the dissatisfaction about the negative energy solutions of the Dirac equation. As such, the paper became immediately ... More Color Superconductivity in High Density QCDDec 15 2005Jan 18 2006We describe the effects of the strange quark mass and of color and electric neutrality on the superconducing phases of QCD. We discuss various phases pointing out the corresponding problems, typically arising from a chromomagnetic instability. We show ... More Bounded cohomology of discrete groupsOct 26 2016Bounded cohomology of groups was first defined by Johnson and Trauber during the seventies in the context of Banach algebras. As an independent and very active research field, however, bounded cohomology started to develop in 1982, thanks to the pioneering ... More A topological approach to leading monomial idealsAug 02 2010Jun 01 2011We introduce a very natural topology on the set of total orderings of monomials of any algebra having a countable basis over a field. This topological space and some notable subspaces are compact. This topological framework allows us to deduce some finiteness ... More Are quantum measurements on macroscopic bodies feasible?Mar 26 2010Mar 29 2010The possibility to test quantum measurement theories is discussed in the more phenomenological framework of the quantum nondemolition theory. A simple test of the hypothesis of the state vector collapse is proposed by looking for deviations from the Boltzmann ... More BlackfoldsJun 10 2011This is an introduction to the blackfold effective worldvolume theory for the dynamics of black branes, as well as its use as an approximate method for the construction of new black hole solutions. We also explain how the theory is useful for the analysis ... More Black Hole Production at a TeVFeb 25 2003In this talk I briefly discuss some features of a striking signature of TeV quantum gravity/strings and large extra dimensions: the production of exotic objects such as black holes, and their stringy precursors, the string resonances at large masses which ... More Black Hole Radiation On and Off the BraneSep 18 2000Sep 26 2000After a brief review of the description of black holes on branes, we examine the evaporation of a small black hole on a brane in a world with large extra dimensions. We show that, contrary to previous claims, most of the energy is radiated into the modes ... More Bn-generalized geometry and G2(2)-structuresJan 15 2013Jul 29 2013We introduce the concept of G2(2)-structure on an orientable 3-manifold M using the setting of generalized geometry of type Bn, study their local deformation by making use of a Moser-type argument, and give a description of the cone of G2(2)-structures. ... More Probing dark energy with future surveysJul 21 2006I review the observational prospects to constrain the equation of state parameter of dark energy and I discuss the potential of future imaging and redshift surveys. Bayesian model selection is used to address the question of the level of accuracy on the ... More X-ray properties of spiral galaxiesNov 01 2002X-ray studies of nearby spiral galaxies with star formation allow us to investigate temperature and spatial distribution of the hot diffuse plasma, and to carry out individual and statistical studies of different classes of discrete sources (low- and ... More Computing Quasidegrees of A-graded ModulesOct 26 2015We describe the main functions of the Macaulay2 package Quasidegrees. The purpose of this package is to compute the quasidegree set of a finitely generated A-graded module presented as the cokernel of a monomial matrix. We provide examples with motivation ... More Relaxation models for Single Helical Reversed Field Pinch plasmasSep 24 2015Oct 26 2016In this paper a relaxation theory, proposed several years ago for plasmas where a single dominant mode is present, is revisited. The solutions of the related eigenvalue problem are numerically calculated and discussed. Although these solutions are very ... More Measuring Inequality and SegregationAug 05 2015In this paper, I introduce the Divergence Index, a conceptually intuitive and methodologically rigorous measure of inequality and segregation. The index measures the difference between a distribution of interest and another empirical, theoretical, or ... More On higher holonomy invariants in higher gauge theory IMay 08 2015This is the first of a series of two technical papers devoted to the analysis of holonomy invariants in strict higher gauge theory with end applications in higher Chern--Simons theory. For a flat 2--connection, we define the 2-holonomy of surface knots ... More Cosmic Rays: What Gamma Rays Can SayDec 23 2014We will review the main channels of gamma ray emission due to the acceleration and propagation of cosmic rays, discussing the cases of both galactic and extra-galactic cosmic rays and their connection with gamma rays observations. Scaling Distances on Finitely Ramified FractalsAug 31 2015Nov 06 2015In previous papers by A. Kameyama and by J. Kigami distances on fractals have been discussed having two different but similar properties. One property is that the maps defining the fractal are Lipschitz of prescribed constants less than 1, the other is ... More A Lie based 4-dimensional higher Chern-Simons theoryDec 18 2015Feb 22 2016We present and study a model of 4-dimensional higher Chern-Simons theory, special Chern-Simons (SCS) theory, instances of which have appeared in the string literature, whose symmetry is encoded in a skeletal semistrict Lie 2-algebra constructed from a ... More Gravitational collapse of homogeneous scalar fieldsJan 05 2005May 27 2005Conditions under which gravity coupled to self interacting scalar field determines singularity formation are found and discussed. It is shown that, under a suitable matching with an external space, the boundary, if collapses completely, may give rise ... More On a conjecture of VarchenkoMar 26 1995In this note we generalize and prove a recent conjecture of Varchenko concerning the number of critical points of a (multivalued) meromorphic function $\phi$ on an algebraic manifold. Under certain conditions, this number turns out to coincide with the ... More Casimir forces and non-Newtonian gravitationDec 19 2006The search for non-relativistic deviations from Newtonian gravitation can lead to new phenomena signalling the unification of gravity with the other fundamental interactions. Various recent theoretical frameworks indicate a possible window for non-Newtonian ... More Computing the R^4 term at two Superstring LoopsFeb 09 2002We use a previously derived integral representation for the four graviton amplitude at two loops in Superstring theory, whose leading term for vanishing momenta gives the two-loop contribution to the R^4 term in the Effective Action. We find by an explicit ... More