We describe how the deformation matrix \Omega ^ , which relates the sources of matter associated with the metric g and the metric q , provides an alternative description for the Einstein tensor, relating it to the energy-moment tensor \tilde^ (q) . We will use gravity f(R) to establish the general mapping equations for scalar fields.

In this paper we study the corrections emergent from a Lorentz-violating CPT-odd extension of the complex scalar sector to the Bose-Einstein condensation and to the thermodynamics parameters. We initially discussed some features of the model to only then compute the corrections to the Bose-Einstein condensation. The calculations were done by computing the generating functional, from which we extract the thermodynamics parameters. We also obtained a Lorentz-violating correction for the critical temperature Tc that sets the Bose-Einstein Condensation

A complete theory of gravity impels us to go beyond Einstein's General Relativity. One promising approach lies in a new class of teleparallel theory of gravity named f (Q), where the nonmetricity Q is responsible for the gravitational interaction. The important roles any of these alternative theories should obey are the energy condition constraints. Such constraints establish the compatibility of a given theory with the causal and geodesic structure of space-time. In this work, we present a complete test of energy conditions for f (Q) gravity models. The energy conditions allowed us to fix our free parameters, restricting the families of f (Q) models compatible with the accelerated expansion our Universe passes through. Our results straight the viability of f (Q) theory, leading us close to the dawn of a complete theory for gravitation.

With the discovery of graphene in 2004, a new line of research in two-dimensional materials was unveiled. As this innovation we find the transition metal dichalcogenides (TMD) materials that became known as last generation graphene since these systems have many degrees of freedom to be explored and understood. We can find the TMD in three different phases, which depends on the number of electrons in the d orbital of the transition metals and the size of the atoms. Usually these materials are found in three polymorphs schematized in 1T, 2H and 3R, where the number represents the number of layers of the unit cell and the characters indicate the trigonal, hexagonal and rhombohedral symmetry, however according to some crystalline systems of these new materials of the TMDC type that we only find in the cubic phase. In this work, we use first principle calculations, based on the Density Functional Theory (DFT), using the generalized gradient (GGA) and local density (LDA) approximations and the PBE and CAPZ functional, used in optimizations and property descriptions structural, electronic and optical, implemented in the computer code CASTEP, to investigate the optical electronic properties of transition metal dichhalcogenides (TMD). The present work consists of the study of materials with the following formation RuX 2 com (X = S, Se é Te). As a result, it was seen that the polymorphic systems of the type RuX 2 their phase is extremely cubic, through the theoretical models of the theory of bands we noticed that the polymorphs have semiconductor characteristics of indirect gap. With the results of the optical properties we calculated \ epsilon for all structures of the type RuX 2 using the functional GGA-PBE and LDA-CAPZ

The work presents the late-time cosmology in f(Q, T) gravity, where dark energy is strictly geometric. We assume that the universe is governed by pressure-less matter that produces a scale factor a(t). We begin by using a well-motivated gravity model f(Q, T)= m Q^ + b T, where m,n, and b are model parameters. Also, constraints on the model parameters from the revised 57 points of Hubble data sets and 580 points of union 2.1 compilation supernovae data sets are placed to investigate the model's cosmological viability. We have also thoroughly examined the existence of dark energy with the assistance of , diagnostic analysis. The present study makes it clear that gravity f(Q, T) can be promising in resolving the existing cosmic acceleration and, thus, an acceptable solution to the issue of dark energy.

Information deformation and loss in jet clustering are one of the major limitations for precisely measuring hadronic events at future ee colliders. Because of their dominance in data, the measurements of such events are crucial for advancing the precision frontier of Higgs and electroweak physics in the next decades. We show that this difficulty can be well-addressed by synergizing the event-level information into the data analysis, with the techniques of deep neutral network. In relation to this, we introduce a CMB-like observable scheme, where the event-level kinematics is encoded as Fox-Wolfram (FW) moments at leading order and multi-spectra at higher orders. Then we develop a series of jet-level (w/ and w/o the FW moments) and event-level classifiers, and analyze their sensitivity performance comparatively with two-jet and four-jet events. As an application, we analyze measuring Higgs decay width at ee colliders with the data of 5ab^-1 @ 240GeV. The precision obtained is significantly better than the baseline ones presented in documents. We expect this strategy to be applied to many other hadronic-event measurements at future ee colliders, and to open a new angle for evaluating their physics capability.

One of the theories that has been taking shape in recent years, both in theoretical and experimental aspects, is the idea that Lorentz’s symmetry can be violated in the high energy regime, on the Planck scale. It seems that on this scale, the physics we know, based on the Standard Model and the Theory of Relativity, should be unified in a theory of quantum gravity. From this scenario, the possibility arises that the Lorentz symmetry, fundamental in Physics, may be broken on this scale of energy. Since the caliber symmetry breaking mechanism that occurs spontaneously and that explains, for example, mass creation in a boson theory, is known, it is possible that Lorentz symmetry can also be broken spontaneously . On the other hand, another phenomenon that generates discussions, but which is more accepted within the community is the possibility that particles that interact with a flutuating quantum field can perform a random movement similar to the observed by Robert Brown in the 19th century with pollen grains. This movement is sometimes called the quantum brownian motion (QBM). It has been shown that QBM can occur in a flat geometry or in a time dependent one. So, a good question to ask is what is the effect of Lorentz’s symmetry breaking for the quantum brownian motion performed by a point particle? in this work, we seek to answer these questions.

General Relativity, proposed by Einstein to describe gravitational phenomena, is a very well-tested theory at the solar system scale. However, in recent decades, new phenomena appeared, giving rise to several new alternative approaches both, on the particle content side, as well as on the gravitational physics one. In particular, the family of metric-affine theories of gravity based on the Ricci tensor (RBGs), formulated "a la Palatini'', can be put in correspondence with existing solutions in General Relativity, and vice versa. This fact makes it possible to use very consistent methods and results from the General Relativity context, to explore new results within the context of these class of metric-affine theories. This method has already been applied to several cases. In the present work we will explore the case of anisotropic fluids.

In this project we discuss the main aspects and results of the phenomenological model MOND (MOdified Newtonian Dynamics). The MOND proposal is based on the modification of Newton's second law, delimiting two acceleration regimes. Thus, we were able to explain in good approximation the phenomenon of mass discrepancy, seen in Weak Gravitational Lenses and in the RotationAl Speed Curve in Spiral Galaxies. To verify the success of the model, we developed a Program with the objective of collecting, organizing and plotting the speed data of the 175 galaxies of the Online Repository SPARC. Using these data, the parameters of the theoretical curves were adjusted by linear regression, allowing to verify the correct functioning of the program, as well as the determination of the value of critical acceleration a 0 that delimits the two dynamic regimes of the MOND model.

In this talk, I study the non-relativistic limit of the Dirac equation for mixed neutrinos. A thorough analysis demonstrates that such a procedure inevitably leads to a redefinition of the inertial mass. This happens because, in contrast to the usual unmixed situations, the antiparticle sector contribution cannot be neglected. Furthermore, one can show that, when a gravitational interaction is switched on, in the weak-field approximation the mass parameter which couples to gravity (gravitational mass) does not undergo the same reformulation as the inertial mass; hence, the breakdown of the weak equivalence principle is unavoidable.

Since the discovery that the Universe is under accelerated expansion in the '90s, several attempts have been made to explain the mechanism that causes this expansion. In this research, we investigate cosmological models using the latest observational datasets - including 41 measurements of the Hubble parameter and the Pantheon sample - and how cosmological observations can be used to estimate the free parameters of these models. We perform cosmological parameter estimation over the ΛCDM and CDM flat models.

The classical and quantum systems are many times seen as disconnected areas of physics and with totally distinct mathematical methods. This is not entirely true, many methods of the classical mechanics are very near to those used in the bases of quantum mechanics as the Poisson brackets, the Hamilton-Jacobi equation and the path integral formalism. In this presentation we will show an interplay between the classical and the quantum world in the path integral formalism. In the classical theory the path integral formalism is useful to describe the brownian motion, a kind of stochastic process in which positions are randomic variables varying according a parameter, the time; these positions are described by a distribution probability. This type of motion is observed, for exemple, in very small particles suspended on a fluid. In order to determine this distribution probability we can use the diffusion equation used by Einstein in his 1906 article about the brownian motion or use the Jaynes principle, a powerful tool of information theory to obtain probability distributions subjected to constraints. With the knowledge of the position distribution we are able to construct the path probability: we consider that the next step of a brownian particle is independent of the previous steps performed (markovian property), due to this property we can associate successive position probabilities and then obtain the Wiener path integral. This path integral gives the probability of a particle describe a given trajectory. An specific use of the Wiener integral is to treat the brownian movement with absorption and in this case is possible to show that the Wiener path integral satisfies the Feynman-Kac formula, a equation that establishes a connection between the stochastic processes theory and the differential equation theory. Modifying the Feynman-Kac formula to the Schrödinger equation we estabilish a map to modify the Wiener path integral and thus obtain the Feynman path integral to quantum mechanics.

The idea of neutron stars was conceived in the 1930s by Walter Baden and Fritz Zwicky, who collaborated to be perhaps the most important forecast in the history of astronomy, with the radical proposal of the possibility of a supernova representing the transition from a common star to a neutron star. In 1967, Jocelyn Bell, from the University of Cambridge, detected precisely periodic pulses coming from the sky, where she believed to be from an extraterrestrial civilization that she called Little Green Man, in December of the same year she found another pulsating radio source and claimed it was a natural radio source from our galaxy. Pulsars are magnetized neutron stars that appear to emit periodic short pulses of radio radiation, such an object is similarly compared to a beacon, they emit rotating beams of radiation continuously and appear to blink each time the beam passes through the observer's line of sight. It is relevant for the study of pulsars to highlight some important physical properties that are: rotation periods; mass and radius; spindonw luminosity; magnetic dipole radiation; characteristic age; dispersion measures. We have covered some general information about the BINGO radio telescope. We made a sketch of the celestial map using pulsed data from ATNF with the settings adapted for BINGO. Finally, we show the schematic of a mini radio telescope that is being built at UFCG, which will be coupled to the CALLISTO spectrometer to measure pulsar signals.

Communications using radio waves based on the GNSS (Global Navigation Satellite System) depend on the spatio-temporal behavior of the ionospheric layer, which is exposed to disturbances that produce distortion of the microwave signals used in satellite technologies. One of the factors that produces these disturbances in the ionosphere are gravity waves, caused by perturbations in the lower atmosphere resulting from topographic and climatic factors. Despite its importance for airworthiness, there are still no technologies to correct or anticipate the effects of these ionospheric instabilities. The objective of this work is to study the formation of gravity waves from meteorological quantities, such as pressure, wind speed, kinetic energy, and potential energy, obtained from all aerodromes in the Brazilian sector. It is worth mentioning that this is the first study that analyzes data from all aerodromes where radiosondeings are routinely performed. We present an extensive and detailed statistical analysis of the time series of measures and quantities related to gravity waves, obtaining a general scenario of its temporal and spatial behavior covering the entire national territory.

Structural analysis and phase transition study of the compound Pb(x)Cd(1-x)TiO3: by X-ray diffraction and Raman spectroscopy This work aims to study the structural properties by X-ray diffraction (XRD) and Raman spectroscopy and phase transition, through vibrational spectra, of compounds of the type ABO3, specifically, ferroelectric materials of the type perovskite. The compounds PbTiO3 (PT), CdTiO3 (CT) and the cationic substitution at site A between these two materials were studied Pb(x)Cd(1-x)TiO3, in the concentrations of x = 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 and 0.0. For each of these values, XRD and Raman measurements were performed. The synthesis was performed by the solid state reaction method, with modification of the reagents PbO and CdO, keeping the molarity of TiO2 constant. The new temperatures of synthesis of the compound were estimated by the Vegard equation. The PbTiO3, at room temperature, is a ferroelectric perovskite that has a tetragonal structure, while the CdTiO3 can be synthesized to have a rhombometric structure of the center-symmetric or orthorhombic perovskite type. However, the synthesis temperatures used in this work favor only the center-symmetrical ilmenite phase of the CT. It was found that the transition temperature of ferroelectric-paraelectric phase (Curie Temperature) of PT is ≈ 490°C. The CT, in its center-symmetric ilmenite phase, is stable at room temperature and at temperatures below 900°C. When replacing the oxides (PbO by CdO) between the lead and cadmium titanates, the transition temperature varies, as well as the other physical properties of the compound, giving rise to a new material. It was also observed that, at a certain concentration, the structural phases of the two titanates coexist, which indicates the possible formation of a particulate composite. Thus, it is possible to obtain a still ferroelectric material with a perovskite structure, with inherent characteristics of the CT, which has a center-symmetrical ilmenite structure. It was possible to analyze the phase transitions of these compounds through the peaks of soft mode (of lower frequency) in the Raman spectrum, with the atomic substitution in the structure of ion A and also through stimulus by temperature, determining the new temperatures phase transition for concentrations of x = 0.9, 0.5, 0.4, 0.2. PbTiO3 is used as a reference for the analysis of measurements, while CdTiO3 has the function of modifying the ferroelectric phase. It is important to highlight that this is a matter of convention, because while studying the changes that the CdO makes in the PbTiO3 phase, at the same time we study the changes that the PbO makes in the structure of CdTiO3. Due to the versatility of the perovskite structure, a material used in several technological applications, the study of these materials and their different configurations is relevant in order to map and identify their potential and possible implementations.

Neste trabalho estão sendo estudadas as biomoléculas presentes no Capsicum Annuum(pimentão) e os efeitos que os solventes provocam nelas. Os pimentões são frutos constituídopor um conjunto complexa de biomoléculas nas quais encontramos os carotenoides e asclorofilas, estes dois tipos de biomoléculas contribuem para que estes frutos apresentemdiferentes cores. O estudo e análise deste conjunto de biomoléculas estão sendo realizadasnas amostras in-natura e em preparação com solvente. Dentre a complexidades dascores dos pimentões foram escolhidos os pimentões nas cores: verde, amarelo, laranja evermelho. Neste sentido, estão sendo usado dois espectrômetros, UV- Visível convencionale Fotoacústico, que possibilitam obter informações dos estados eletrônicos das biomoléculas,com princípios de detecção diferente possibilitando resultados experimentais mais robustos.

The search for new materials has aroused the increasing interest of researchers from different areas, especially if such materials enable the development of smaller and more efficient devices than others already on the market. Among the main types of materials sought are those that can be obtained in two-dimensional (2D) form, due to the successful discovery of graphene, which is a 2D material with excellent electronic and mechanical properties, for example. A class of materials that can be obtained in 2D form and that has gained prominence in recent times is that of Transition Metal Dichalcogenides (TMDs). Some of these materials are already well known and several works have used calculations of first principles through the Density Functional Theory (DFT) to obtain properties of two-dimensional TMDs. The possibility of predicting properties (electronic and vibrational, for example) and the structure of TMDs through computer simulations is extremely advantageous, as it makes a previous experimental study of such materials unnecessary. Thus, in this work, a study will be carried out on two-dimensional materials, especially on TMDs and their characteristics. In addition, the DFT will be studied in order to describe how such a theory was built and on its computational implementation, which is what makes it possible to perform computer simulations of multi-electronic systems. Finally, a representation of the gains from studying materials such as transition metal dichalcogenides through the density functional theory will be shown.