I present the fundamentals of geometrothermodynamics (GTD), a formalism that represents in an invariant way thermodynamic laws and properties in terms of geometric concepts. The GTD of black holes is considered as a particular example and it is shown that a Legendre invariant metric, in which the mass, angular momentum and electric charge are considered as coordinates, can be used to describe...
In this talk I address Regular Static Spherically Symmetric Black Holes (BH) constructed by introducing a de Sitter core, like the Hayward BH (HBH), then I compare the different trajectories in free fall, in the interior of the horizon, between a regular (HBH) and a singular (Reissner-Nordstrom) BH; the energy conditions are discussed as well as for the Regular Black Holes sourced by nonlinear...
We propose in this letter a relativistic coordinate independent
interpretation for Milgrom's acceleration $a_{0}=1.2 \times 10^{-8}\hbox{cm/s}^{2}$ through a geometric constraint obtained from the product of the Kretschmann invariant scalar times the surface area of 2--spheres defined through suitable characteristic length scales for local and cosmic regimes, described by Schwarzschild and...
A new general relativistic method for estimating the mass and spin parameters of a Kerr black hole (BH) from observational data is presented, i.e. from the red/blueshift of photons emitted by certain bodies orbiting around the BH, and the parameters characterizing their orbits (the radius and the polar angle for generic elliptical trajectories). With this method one can predict, and eventually...
We present theoretical and numerical results for the statistical averages of the scattered waves in disordered waveguides. The theoretical results, based on a perturbative method, show that the averages scattering amplitudes of the disordered region depend only on a few characteristic lengths related to microscopic details of the disorder: the mean free paths. Theoretical average amplitudes...
In arbitrary dimension, we consider a theory described by the most general quadratic curvature corrections of Einstein gravity together with a self-interacting nonminimally coupled scalar field. This theory is shown to admit five different families of Lifshitz black holes dressed with a nontrivial scalar field. The entropy of these configurations is microscopically computed by means of a...
The interest in Open Quantum Systems (OQS) has increased as OQS has been applied for the study of diverse physical phenomena. In this work we study the Wigner functions of the Harmonic Oscillator (HO) and two coupled Harmonic Oscillators (the Moshinsky atom). Both models were coupled with a bath under two different coupling bath-system regimes: a) pure-dephasing without relaxation and b)...
We derive the electrically charged static black hole spacetime of the Einstein-Euler-Heisenberg theory, in terms of the Plebański dual variables. This solution is a non-linear electromagnetic generalization of the Reissner-Nordström solution and it is characterized by three parameters: mass M, electric charge Q_e , and Euler-Heisenberg non-linearity parameter A. We study the trajectories of...
The design of artificial materials, with emerging anomalous properties, is a very active frontier research today due to the multiple and novel applications based on new physics. These new materials, also called metamaterials, are characterized by their wave phenomenology that defies our intuition: superfocusing, invisibility and slowing down, among others.
The main challenge of...
A way to construct a warped black hole in IIB supergravity will be presented. The two parameters that characterize the resulting solution are the size of the horizon and the warping factor. A D7-brane will be embedded in this background in such a way that a particular asymptotic behavior is achieved. Depending on the value of the parameters of the black hole, the embedding of the D7-brane can...
The Earth's geoid is one of the most important fundamental concepts to provide a gravity field-related height reference in geodesy and associated sciences. To keep up with the ever-increasing experimental capabilities and to consistently interpret high-precision measurements without any doubt, a relativistic treatment of geodetic notions (including the geoid) within Einstein's theory of...
Scalar Fields in the form of Bose-Einstein condensates (BEC's), seem to be a good candidate to describe dark matter in the universe. Even more, the existence of black holes in the center of some galaxies could be astrophysical phenomena that lead to the so-called quasi-bound states for the condensate that, in this scenario, can be interpreted as a galactic dark matter halo. By using the...
The proposal of loop (polymer) quantization of general relativity can be adapted to systems with finite number of degrees of freedom like each one of the infinite modes (harmonic oscillators) forming a scalar field to give rise to the Hosain-Husain-Seahra (HHS) model. This model crucially relies on the properties of the Mathieu solutions of the quantum pendulum that corresponds to the polymer...
We consider a simple PT-symmetric tight-binding chain with gain and loss in a symmetric configuration. Using the explicit expressions for the eigenvalues and eigenvectors of the model, we obtain the values of the parameters at which exceptional points occur, and determine the behavior of the eigenvalues and eigenfunctions around these exceptional points perturbatively. These results are used...
In the last few years our group have been focusing on three main research areas. The first one concerns the study of cw-laser induced transformations in metal oxides and metals as molybdenum oxide and bismuth thin films. The second one is the study of pulsed ns-laser induced effects on some metallic materials as titanium, molybdenum and bismuth thin films, the third one and more recent is the...
In this talk we review some characteristics of the $\alpha$' corrections of black holes in the
context of Heterotic Superstring effective field theory. In particular we will discuss the corrections to non-extremal 4-dimensional dyonic Reissner-Nordström Black Holes. We argue that to first order in α', consistency with the equations of motion of the Heterotic Superstring demands additional...
In this work we present a new code to study perturbation theory in modified gravity. The code is based on the computation of the Lagrangian Perturbation Theory (LPT) kernels. From these kernel functions we can compute the correlation function in Convolution-LPT (CLPT) and the power spectrum in Standard Perturbation Theory (SPT). We applied the code to compute the correlation function in CLPT...
Time-driven quantum systems are essential in many different fields of physics as cold atoms, solid-state, optics, etc. Many of their properties are encoded in the time evolution operator or the effective Hamiltonian. Finding these operators usually requires very complicated calculations that often involve some approximations. In this talk, we present a theoretical model that exploits the...
We have observed anomalous conical emission from the first resonant transition of calcium (λca=422.67nm) using two types of laser beam, Gaussian and zeroth-order Bessel beams. We used the third harmonic of a Nd:YAG laser to pump a homemade tunable dye laser to excite the transition, and a 1° axicon to produce the Bessel beams. The conical emission featured different half-angles for the same...
We consider the construction of a S0(4) scalar field theory non minimally coupled to a Couloumb potential. Using the symmetry we calculate the hydrogen atom spectrum. We find that the symmetry have among its generators a constant of motion that we can identify with a Relativistic Runge-Lenz vector.
I will first present a formalism to study symmetries in the context of diffeomorphism-invariant gauge theories. With it, I will show a universal symmetry algebra that contains the gauge symmetry and a covariant version of the diffeomorphisms. Then, I will include nondynamical fields that are supposed to describe effects associated with more fundamental degrees of freedom. Typically, these...
We review the idea of noncommutative smeared distributions of mass and charge as a tool for the construction of noncommutative inspired black holes. These solutions are free of singularities and possess interesting properties; using them, we discuss some of their applications in different physical scenarios.
We present a quantum framework for coarse graining and fuzzy measurements in a multiparticle system, based solely on what might be physically measured. For example the case of coarse graining, we assume that the detectors can measure only randomly selected particles with a physically motivated distribution. For the case of fuzzy measurements, we assume that the detectors might be placed...
We investigate a quantum geometric space in the context of what could be considered an emerging effective theory from quantum gravity. Specifically we consider a two-parameter class of twisted Poincaré algebras, from which Lie-algebraic noncommutativities of the translations are derived as well as associative star-products, deformed Riemannian geometries, Lie-algebraic twisted Minkowski...
In year 2004 we created the "Laboratorio de Fotomedicina, Biofotónica y Espectroscopía Láser de Pulsos Ultracortos". Since then we have consolidated the Laser Ablation of Solids in Liquids (LASL) technique through a 30 ps Nd:YAG laser system, UV-Vis spectroscopy and photoluminescence (PL) spectroscopy. Our research group focuses on the following topics: synthesis of colloidal nanoparticles by...
In this work we explore the possibility of a noncommutative origin to the cosmological constant. The results are derived in the context of noncommutative cosmology, where noncommutativity is introduced by a deformation on the minisuperspace variables. These ideas are explored in several examples, the main result is an effective cosmological constant in terms of the deformation parameters.
We present the entanglement measures of a tetrapartite W-Class entangled system in noninertial frame, where the transformation between Minkowski and Rindler coordinates is applied. Two cases are considered. First, when one qubit has uniform acceleration whilst the other three remain stationary. Second, when two qubits have nonuniform accelerations and the others stay inertial. The 1-1 tangle,...
Pulsed laser ablation in liquid technique is used frequently due to the advantage of obtention of stable, surfactant free nanomaterials in colloidal form. In this work, we synthesized semiconductor nanocolloids with laser ablation in liquid. The ablation process was carried out with pure Sb2S3 target and with additions of polycrystalline-Si and monocrystalline-Si in ethyl alcohol solution and...
Thin films of vanadium oxide compounded with silver were prepared by pulsed laser deposition using a two parallel plasmas and sequential plasmas configuration on glass and silicon substrates (100). These substrates were placed in front of the expansion line of the plasmas at a distance of 6 cm. For the array of parallel plasmas a high purity vanadium and silver targets were placed...
In this work the quantization of the superstring is performed via the deformation quantization formalism in the Neveu-Schwarz- Ramond approach. We use the Weyl-Wigner-Moyal-Groenewold formalism to carry out the quantization. The Stratonovich-Weyl operator, the Moyal star product and the Wigner function of the ground state for the superstring are obtained. The spectrum of states is also...
In this talk it is introduced the basics of Classical Plate Theory and Random Matrix Theory in order to appreciate the discovery and consequences of avoided crossings in a free vibrating rectangular elastic billiard. Mathematical, Numerical and Experimental evidences are presented.
In this work we present some results and analysis concerning the processing of semiconducting CdSe nanoparticles obtained by laser ablation of diluted CdSe powder in acetone. A Nd-YAG pulsed laser was used for ablation, tuned at the first and second harmonic, λ=1064 and 532 nm, 50 Hz frequency repetition during 30 minutes. The experiment was performed at different power intensities. An...
Uncertainty relations define one of the main differences between classical mechanics and quantum mechanics and are of fundamental importance in the description of quantum systems. In this talk the construction of uncertainty relations for systems with arbitrary phase spaces by means of deformation quantization formalism is discussed. In particular, the expressions of the so-called...
We describe the inverse method approach to determine parameters of astrophysical systems involving black holes. In the first case we review the reconstruction of binary black hole parameters out of the gravitational wave signal. In a second case we estimate parameters of a black hole out of the image observed, produced by matter around the black hole. In the two scenarios we describe the state...
I will discuss some ideas about the interface between the quantum and gravitational realms, and the emergence of space-time itself, which led us to specific speculations about the way in which anticipated discrete aspects of quantum gravity might become manifest at the macroscopic level. We then will discuss an alternative description of gravitation, initially explored by Einstein, and known...
