http://repositorio.ugto.mx/handle/20.500.12059/4156 Tesis y Trabajos de Posgrado Sat, 31 Oct 2026 14:28:00 GMT 2026-10-31T14:28:00Z http://repositorio.ugto.mx/handle/20.500.12059/14242 Title: Correcciones de Ungravity a las pruebas clásicas de la Relatividad General Authors: Pérez Cuéllar, Gemma Elizabeth Contributor: OSCAR MIGUEL SABIDO MORENO Abstract: Se desarrollan las pruebas clásicas de Relatividad General (precesión del perihelio de Mercurio, deflexión de la luz y corrimiento al rojo gravitacional) a partir de ecuaciones de gravedad con modificaciones provenientes del sector de gravedad del modelo de Unparticles. De lo anterior, comparando los resultados con los valores observados experimentalmente para cada uno de los fenómenos anteriormente mencionados, se obtuvieron cotas para uno de los parámetros del modelo (un parámetro de longitud) y con ello se acotaron los posibles valores de la energía efectiva, en función de la masa característica del modelo. Tue, 10 May 2022 00:00:00 GMT http://repositorio.ugto.mx/handle/20.500.12059/14242 2022-05-10T00:00:00Z http://repositorio.ugto.mx/handle/20.500.12059/14056 Title: Computational study of phage adsorption dynamics on cell membranes Authors: Segoviano Caudillo, Isael Aaron Contributor: FRANCISCO ALARCON OSEGUERA Abstract: The motivation of this work originated from the interest in understanding viral adsorption phenomena from a physical perspective, particularly in systems involving anisotropic particles such as bacteriophages. When suspended in a fluid, bacteriophages interact with bacterial surfaces through a combination of hydrodynamic effects, steric constraints, and anisotropic surface affinities. Therefore, their adsorption and alignment on cellular membranes are governed not only by biochemical interactions but also by fluid-mediated transport and orientation processes. To capture these features, we developed a coarse-grained model composed of anisotropic dimers embedded in a dissipative fluid. The dimers represent elongated viral particles, where anisotropy is introduced through interaction asymmetry between the two components. Bacterial surfaces were represented by granular walls, which allow control of physical characteristics such as roughness and affinity distribution. The construction of the model is intentionally general: although motivated by phage–bacteria interactions, it can be tuned to reproduce other physical systems that share similar geometric constraints, adsorption mechanisms, or anisotropic interactions. Dissipative Particle Dynamics (DPD) was selected as the simulation method due to its ability to simultaneously reproduce hydrodynamic behavior, excluded-volume interactions, and mesoscale thermal fluctuations. Within this framework, we performed systematic studies on the effects of wall morphology, surface affinity, hydrophobicity on dimer adsorption and an analysis of the orientational behavior of the dimers was conducted, revealing how hydrodynamic conditions and heterogeneous surface affinities influence the system. Sun, 01 Jun 2025 00:00:00 GMT http://repositorio.ugto.mx/handle/20.500.12059/14056 2025-06-01T00:00:00Z http://repositorio.ugto.mx/handle/20.500.12059/13949 Title: Higher-Order dark matter: from non-relativistic Proca stars to cosmological spinor production Authors: Preciado Govea, Edgar Iván Contributor: Diez Tejedor, Alberto Abstract: This thesis explores the possibilities of forming compact dark matter objects as solutions to the Einstein-Klein-Gordon and Einstein-Proca field equations, as well as accounting for the mechanism of dark matter production through gravitational particle production. According to quantum mechanics, particles are subdivided into two groups: those with integer spin (bosons) and those with half-integer spin (fermions). The former are capable of forming particle condensates in the ground state, while the latter, limited by FermiDirac statistics, are forced to successively occupy higher energy levels. Here we will focus on describing the equilibrium configurations of compact objects of self-gravitating and self-interacting particles with spin s = 0 and s = 1, which share similar characteristics to their counterparts, the compact objects composed of fermions. On the other hand, one of the most notable results of the semiclassical treatment of quantum fields on curved spaces predicts the gravitational production of particles due to gravitational effects, in abundances that could account for the dark matter bounds imposed by current observations [4, 5]. Here we will focus on describing this phenomenon for quantum fields with spin s = 0 and spin s = ½ at different orders of approximation. In both objectives, we describe dark matter as a field that interacts only gravitationally with the rest of the matter. Both objectives aim to address particular issues (one intends to solve astrophysical and cosmological problems, while the other intends to explain the mechanism of production of these particles); however, they equally intend to account for the gravitational presence of dark matter in the observable universe. In both cases, we will explore different regimes of approximations for the bosonic or fermionic dark matter field according to each chapter. Wed, 01 Jan 2025 00:00:00 GMT http://repositorio.ugto.mx/handle/20.500.12059/13949 2025-01-01T00:00:00Z http://repositorio.ugto.mx/handle/20.500.12059/13886 Title: Electrical and magnetic stimulation for the treatment of patients with cardiac and neurological conditions Authors: Rodríguez Calvo, Edwin Fernando Contributor: Córdova Fraga, Teodoro Abstract: Electrical stimulation and electrophysiological signal analysis have proven to be key tools in biomedical research and the development of therapeutic devices. Various studies have explored their application in the modulation of nervous system activity, the treatment of pathologies such as migraines and arrhythmias, and the identification of neuronal biomarkers through EEG. In this context, non-invasive electrical stimulation devices have been developed with the ability to vary key parameters such as frequency, current, and pulse width, allowing personalized adaptation for the research and treatment of conditions related to the vagus nerve. A system has been designed to correct arrhythmias by means of bioelectromagnetic stimulation of the sinus node and cervical sympathetic ganglia, demonstrating a promising response in heart rhythm regulation. Likewise, studies have been conducted on the relationship between brain activity and migraines through the analysis of EEG signals. Interactive games have been designed to induce states of concentration and activate specific brain regions, providing a possible electrophysiological biomarker of migraines. In addition, a neuromodulation device has been developed for the simultaneous stimulation of the vagus and trigeminal nerves, evaluating its effect on pain reduction and cognitive activity by recording EEG signals from the prefrontal lobe. These advances reflect the potential of biomedical technology in the exploration of the nervous system and the development of alternative therapies for various pathologies, offering new perspectives in the research and treatment of neurological and cardiovascular diseases. Tue, 01 Jul 2025 00:00:00 GMT http://repositorio.ugto.mx/handle/20.500.12059/13886 2025-07-01T00:00:00Z