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Diego Julio Cirilo-Lombardo

Publications and source records attributed to Diego Julio Cirilo-Lombardo.

29 records · Page 2Linked to original sources
arXiv2014

The Affine Structure of Gravitational Theories: Symplectic Groups and Geometry

We give a geometrical description of gravitational theories from the viewpoint of symmetries and affine structure. We show how gravity, considered as a gauge theory, can be consistently achieved by the nonlinear realization of the conformal-affine group in an indirect manner: due the partial isomorphism between $CA\left( 3,1\right) $ and the centrally extended $Sp\left( 8\right) $, we perform a nonlinear realization of the centrally extended (CE)$Sp\left( 8\right) $ in its semi-simple version. In particular, starting from the bundle structure of gravity, we derive the conformal-affine Lie algebra and then, by the non-linear realization, we define the coset field transformations, the Cartan forms and the inverse Higgs constraints. Finally we discuss the geometrical Lagrangians where all the information on matter fields and their interactions can be contained.

gr-qc↗
arXiv2013

Solar neutrinos, helicity effects and new affine gravity with torsion

New f(R,T) model of gravitation, introduced previously by the author, is considered. It is based on an affine geometrical construction in which the torsion is a dynamical field, the coupling is minimal and the theory is Lorentz invariant by construction. It was shown that the Dirac equation emerges from the same space time and acquires a modification (coupling-like) of the form γ^{α}j((1-d)/d)γh_{α}, with h_{α} the torsion axial vector, j a parameter of pure geometrical nature and d, the spacetime dimension. In the present work it is shown that this interaction produces a mechanism of spin (helicity) flipping, with its consequent weak symmetry violation. The cross section of this process is explicitly calculated and a logaritmical energy dependence (even at high energies) is found. This behavior is reminiscent of similar computations made by Hans Bethe in the context of neutrino astrophysics. These results are applied to the solar neutrino case and compared with similar results coming from a gravitational model with torsion of string theory type and within the standard model context respectively.

hep-th↗
arXiv2013

Coherent States, Superpositions of Coherent States and Uncertainty Relations on a Möbius Strip

Since symmetry properties of coherent states (CS) on Möbius strip (MS) and fermions are closely related, CS on MS are naturally associated to the topological properties of fermionic fields. Here we consider CS and superpositions of coherent states (SCS) on MS. We extend a recent propose of CS on MS (Cirilo-Lombardo, 2012 [25]), including the analysis of periodic behaviors of CS and SCS on MS and the uncertainty relations associated to angular momentum and the phase angle. The advantage of CS and SCS on MS with respect to the standard ones and potential applications in continuous variable quantum computation are also addressed.

quant-ph↗
arXiv2012

Geometrical properties of Riemannian superspaces, observables and physical states

Classical and quantum aspects of physical systems that can be described by Riemannian non degenerate superspaces are analyzed from the topological and geometrical points of view. For the N=1 case the simplest supermetric introduced in [Physics Letters B \textbf{661}, (2008),186] have the correct number of degrees of freedom for the fermion fields and the super-momentum fulfil the mass shell condition, in sharp contrast with other cases in the literature where the supermetric is degenerate. This fact leads a deviation of the 4-impulse (e.g. mass constraint) that can be mechanically interpreted as a modification of the Newton's law. Quantum aspects of the physical states and the basic states and the projection relation between them, are completely described due the introduction of a new Majorana-Weyl representation of the generators of the underlying group manifold. A new oscillatory fermionic effect in the $B_{0}$ part of the vaccum solution involving the chiral and antichiral components of this Majorana bispinor is explicitly shown.

hep-th↗
arXiv2012

The mathematical and geometrical structure of the spacetime and the concept of unification, matter and energy

Geometrical analysis of a new type of Unified Field Theoretical models follow the guidelines of previous works of the authors is presented. These new unified theoretical models are characterized by an underlying hypercomplex structure, zero non-metricity and the geometrical action is determined fundamentally by the curvature provenient of the breaking of symmetry of a group manifold in higher dimensions. This mechanism of Cartan-MacDowell-Mansouri type, permits us to construct geometrical actions of determinantal type leading a non topological physical Lagrangian due the splitting of a reductive geometry. Our goal is to take advantage of the geometrical and topological properties of this theory in order to determine the minimal group structure of the resultant spacetime Manifold able to support a fermionic structure. From this fact, the relation between antisymmetric torsion and Dirac structure\ of the spacetime is determined and the existence of an important contribution of the torsion to the giromagnetic factor of the fermions, shown. Also we resume and analyze previous cosmological solutions in this new UFT where, as in our work [Class. Quantum Grav. 22 (2005) 4987--5004] for the non abelian Born-Infeld model, the Hosoya and Ogura ansatz is introduced for the important cases of tratorial, totally antisymmetric and general torsion fields. In the case of spacetimes with torsion the real meaning of the spin-frame alignment is find and the question of the minimal coupling is discussed.

hep-th↗
arXiv2012

Information metric from Riemannian superspaces

The Fisher's information metric is introduced in order to find the real meaning of the probability distribution in classical and quantum systems described by Riemaniann non-degenerated superspaces. In particular, the physical rôle played by the coefficients $\mathbf{a}$ and $\mathbf{a}^\ast$ of the pure fermionic part of a genuine emergent metric solution, obtained in previous work is explored. To this end, two characteristic viable distribution functions are used as input in the Fisher definition: first, a Lagrangian generalization of the Hitchin Yang-Mills prescription and, second, the probability current associated to the emergent non-degenerate superspace geometry. Explicitly, we have found that the metric solution of the superspace allows establish a connexion between the Fisher metric and its quantum counterpart, corroborating early conjectures by Caianiello {\em et al.} This quantum mechanical extension of the Fisher metric is described by the $CP^1$ structure of the Fubini-Study metric, with coordinates $\mathbf{a}$ and $\mathbf{a}^\ast$.

hep-th↗
arXiv2012

Quantum particle on a Mobius strip, coherent states and projection operators

The coherent states for a quantum particle on a Möbius strip are constructed and their relation with the natural phase space for fermionic fields is shown. The explicit comparison of the obtained states with previous works where the cylinder quantization was used and the spin 1/2 was introduced by hand is given, and the relation between the geometrical phase space, constraints and projection operators is analyzed and discussed.

math-ph↗
arXiv2009

Non-compact Groups, Coherent States, Relativistic Wave Equations and the Harmonic Oscillator II: Physical and Geometrical Considerations

The physical meaning of the particularly simple non-degenerate supermetric, introduced in the previous part by the authors, is elucidated and the possible connection with processes of topological origin in high energy physics is analyzed and discussed. New possible mechanism of the localization of the fields in a particular sector of the supermanifold is proposed and the similarity and differences with a 5-dimensional warped model are shown. The relation with gauge theories of supergravity based in the $OSP(1/4)$ group is explicitly given and the possible original action is presented. We also show that in this non-degenerate super-model the physic states, in contrast with the basic states, are observables and can be interpreted as tomographic projections or generalized representations of operators belonging to the metaplectic group $Mp(2)$. The advantage of geometrical formulations based on non-degenerate super-manifolds over degenerate ones is pointed out and the description and the analysis of some interesting aspects of the simplest Riemannian superspaces are presented from the point of view of the possible vacuum solutions.

hep-th↗
arXiv2007

Rotating charged Black Holes in Einstein-Born-Infeld theories and their ADM mass

In this work, the solution of the Einstein equations for a slowly rotating black hole with Born-Infeld charge is obtained. Geometrical properties and horizons of this solution are analyzed. The conditions when the ADM mass (as in the nonlinear static cases) and the ADM angular momentum of the system have been modified by the non linear electromagnetic field of the black hole, are considered.

gr-qc↗
arXiv2006

Non-Abelian Born-Infeld action, geometry and supersymmetry

In this work, we propose a new non-abelian generalization of the Born- Infeld lagrangian. It is based on a geometrical property of the abelian Born-Infeld lagrangian in its determinantal form. Our goal is to extend the abelian second type Born-Infeld action to the non-abelian form preserving this geometrical property, that permits to compute the generalized volume element as a linear combination of the components of metric and the Yang-Mills energy-momentum tensors. Under BPS-like condition, the action proposed reduces to that of Yang-Mills theory, independently of the gauge group. New instanton-wormhole solution and static and spherically symmetric solution in curved space-time for a SU(2) isotopic ansatz is solved and the N=1 supersymmetric extension of the model is performed.

hep-th↗