Laboratorio de Modelación Matemática y Física Teórica

Laboratorio de Modelación Matemática y Física Teórica

Responsable/ jefe de laboratorio

Dr. Ricardo Armando González Silva

ricardo.gsilva@academicos.udg.mx

Enfoque

Investigación

División

Estudios de la Biodiversidad e Innovación Tecnológica

Departamento

Dpto. de Ciencias Exactas y Tecnología

Áreas

Nombre de área

Responsable de área

Modelación y simulación Matemática

Dr. Ricardo Armando González Silva

Clasificación en las áreas de conocimiento SNI

Área I: Física, matemáticas y ciencias de la tierra

Servicios

  • Alumnos: Docencia y dirección de tesis a nivel licenciatura y posgrado.
  • Académicos: Asesoría en problemas académicos y de investigación.
  • Externos: Servicio de consultoría al sector público y privado.

Líneas de Investigación

  • Modelación y simulación matemática
  • Física teórica

Objetivo

General: Sincronizar y asistir actividades de investigación, análisis y asesoría de los proyectos del CA.

Particulares

  • Mantener sesiones de asesoría en los proyectos de los alumnos de posgrado asesorados por los integrantes del CA
  • Establecer un ambiente de investigación conjunta para los proyectos del CA
  • Desarrollo de cálculos analíticos y numéricos de los proyectos de investigación del CA

Planta académica

Nombre

Grado académico

Especialidad

Nombramiento

Categoría

Dr. Luis Armando Gallegos Infante (SNI I)

Doctorado en Ciencias

Física

Profesor Investigador 

Asociado C

Dr. Héctor Vargas Rodríguez (SNI I)

Doctorado en Ciencias

Física

Profesor Investigador

Asociado C

Dr. Ricardo Armando González Silva

Doctorado en Ciencias

Matemáticas

Profesor Investigador

Titular A





Programas educativos o carreras atendidas

Posgrado:

» Maestría en Ciencia y Tecnología

» Doctorado en Ciencia y Tecnología

 

Licenciatura:

» Ing.Administración Industrial

» Ingeniería en Mecatrónica

» Ingeniería Mecánica Eléctrica

 

Materias a las que atiende/impartidas

N/A

Equipamiento destacado (hardware/software)

» Software de cálculo científico y simulación computacional, tales como: MatLab, Maple, Mathematica, Python y Netlogo, (entre otros).

Horarios de atención

Agendados previo acuerdo


Proyectos de Investigación vigentes

Estudio teórico de terapias optimizadas y marcadores basados en imagen en gliomas: Un enfoque multidisciplinario utilizando un modelado matemático
Descripción del proyecto de Investigación Se pretende llevar a cabo un estudio retrospectivo observacional para estudiar desde un punto de vista teórico la optimización de terapias y marcadores basados en imagen usando modelos matemáticos.
Fuente de Financiamiento Ninguna
Fecha (año) de inicio de la Investigación Mayo 2023
Co-autores Dr. Raúl Allan Hernández Estrada
Dr. Luis Armando Gallegos Infante
Dr. Luis Enrique Ayala Hernández
Dra. Luz Fabiola Velázquez Fernández
Dra. Alejandra Espinosa Garrido
Dr. Raúl Gómez Gómez
Diseño, análisis y simulación de modelos matemáticos robustos para la propagación de enfermedades infecciosas.
Descripción del proyecto de Investigación Proponer y analizar modelos matemáticos basados en ecuaciones diferenciales parciales, que describan la propagación de enfermedades infecciosas, tales como el COVID-19. El modelo contará con fuerte análisis matemático, numérico y computacional.
Fuente de Financiamiento CONAHCYT
Fecha (año) de inicio de la Investigación Diciembre 2022
Co-autores Luis Romeo Martínez Jiménez
Luis Armando Gallegos Infante
Jorge Eduardo Macías Díaz
Efectos físicos en marcos de referencia arbitrarios.
Descripción del proyecto de Investigación En este proyecto investigamos diversos efectos físicos en las relatividades especial y general que se presentan cuando son estudiados desde el punto de vista de distintas familias de observadores, que poseen distintos estados de movimiento. En particular, en el caso de los campos electromagnéticos, nos interesa los efectos físicos medibles por aquellas familias de observadores para las cuales el vector de Poynting se anula; en el caso de los campos gravitacionales nos interesan los efectos gravito–eléctricos y gravito–magnéticos  medidos por aquellas familias de observadores para las cuales el super-vector de Poynting se anula. Las herramientas matemáticas utilizadas en este proyecto son el cálculo tensorial, la geometría Riemanniana, la teoría de formas diferenciales de Cartan,  la teoría de marcos de referencia y la relatividad general.
Fuente de Financiamiento Ninguna
Fecha (año) de inicio de la Investigación Diciembre 2023
Co-autores María Guadalupe Medina Guevara
Héctor Vargas Rodríguez
Aplicación de herramientas matemáticas para la identificación de biomarcadores y de esquemas de tratamiento con mejores beneficios terapéuticos en gliomas.
Descripción del proyecto de Investigación Este proyecto busca aplicar diversas herramientas matemáticas en el campo de la medicina. Investigaciones recientes señalan la necesidad de la práctica médica de adoptar métodos cuantitativos más precisos para entender, diagnosticar y tratar de mejor manera las enfermedades. En primer lugar, se pretende caracterizar geométricamente los estudios de imagen de tumores gliales para estudiar la relación de su geometría con el tiempo de supervivencia y el pronóstico de la cirugía. Por otro lado, se desarrollarán modelos matemáticos, los cuales serán parametrizados con la información obtenida en la caracterización, para simular computacionalmente diferentes esquemas de administración de terapia con la intención de exponer los fundamentos que aportan la mayor calidad de vida para el paciente.
Fuente de Financiamiento CONAHCYT
Fecha (año) de inicio de la Investigación Septiembre 2023
Co-autores Luis Enrique Ayala Hernández
Luis Armando Gallegos Infante
Raúl Allan Hernández Estrada
Omar Jesús Díaz Cázares

Publicaciones Relevantes

A fractional tumor-growth model and the determination of the power law for different cancers based on data fitting
Descripción del proyecto de Investigación We study a fractional model for tumor growth and derive its general solution, the blow-up time and the radius of convergence. The model is simplified then to fit human data. The results show that there is a noticeable variation in the value of the scaling exponent depending on whether the model is fractional or integer. This supports the idea that the inclusion of memory effects may become relevant in the study of tumor growth via the scaling exponent.
Fecha (año) de inicio de la Investigación 2023
Fecha (año) de fin de la Investigación 2024
Co-autores Romeo Martínez
Armando Gallegos
Jorge E. Macías-Díaz
On a deterministic mathematical model which efficiently predicts the protective effect of a plant extract mixture in cirrhotic rats
Descripción del proyecto de Investigación In this work, we propose a mathematical model that describes liver evolution and concentrations of alanine aminotransferase and aspartate aminotransferase in a group of rats damaged with carbon tetrachloride. Carbon tetrachloride was employed to induce cirrhosis. A second group damaged with carbon tetrachloride was exposed simultaneously to a plant extract as hepatoprotective agent. The model reproduces the data obtained in the experiment reported in [Rev. Cub. Plant. Med. 22(1),2017], and predicts that using the plants extract helps to get a better natural recovery after the treatment. Computer simulations show that the extract reduces the damage velocity but does not avoid it entirely. The present paper is the first report in the literature in which a mathematical model reliably predicts the protective effect of a plant extract mixture in rats with cirrhosis disease. The results reported in this manuscript could be used in the future to help in fighting cirrhotic conditions in humans, though more experimental and mathematical work is required in that case.
Fecha (año) de inicio de la Investigación 2019
Fecha (año) de fin de la Investigación 2024
Co-autores Luis E. Ayala-Hernández, 
Gabriela Rosales-Muñoz, 
Armando Gallegos, 
María L. Miranda-Beltrán
Jorge E. Macías-Díaz
Dynamics of coexisting rotating waves in unidirectional rings of bistable Duffing oscillators
Descripción del proyecto de Investigación We study the dynamics of multistable coexisting rotating waves that propagate along a unidirectional ring consisting of coupled double well Duffing oscillators with different numbers of oscillators. By employing time series analysis, phase portraits, bifurcation diagrams, and basins of attraction, we provide evidence of multistability on the route from coexisting stable equilibria to hyperchaos via a sequence of bifurcations, including the Hopf bifurcation, torus bifurcations, and crisis bifurcations, as the coupling strength is increased. The specific bifurcation route depends on whether the ring comprises an even or odd number of oscillators. In the case of an even number of oscillators, we observe the existence of up to 32 coexisting stable fixed points at relatively weak coupling strengths, while a ring with an odd number of oscillators exhibits 20 coexisting stable equilibria. As the coupling strength increases, a hidden amplitude death attractor is born in an inverse supercritical pitchfork bifurcation in the ring with an even number of oscillators, coexisting with various homoclinic and heteroclinic orbits. Additionally, for stronger coupling, amplitude death coexists with chaos. Notably, the rotating wave speed of all coexisting limit cycles remains approximately constant and undergoes an exponential decrease as the coupling strength is increased. At the same time, the wave frequency varies among different coexisting orbits, exhibiting an almost linear growth with the coupling strength. It is worth mentioning that orbits originating from stronger coupling strengths possess higher frequencies.
Fecha (año) de inicio de la Investigación 2020
Fecha (año) de fin de la Investigación 2023
Co-autores J. J. Barba-Franco,
A. Gallegos,
R. Jaimes-Reátegui,
J. Muñoz-Maciel,  
A. N. Pisarchik
Integral of motion and nonlinear dynamics of three Duffing oscillators with weak or strong bidirectional coupling
Descripción del proyecto de Investigación We present a system composed of three identical Duffing oscillators coupled bidirectionally. Starting from a Lagrangian that describes the system, an integral of motion is obtained by means of Noether’s theorem. The dynamics of the model is studied using bifurcation diagrams, Lyapunov exponents, time-series analysis, phase spaces, Poincaré sections, spatiotemporal and integral of motion planes. The analysis focuses on the monostable and bistable cases of the Duffing oscillator potential, in which a confined movement is guaranteed. In particular, it is observed that the system shows a chaotic behavior for small values of the coupling parameter for the bistable case. This is one of the first articles in the literature in which non-trivial integrals of motion are obtained for a system of three Duffing oscillators coupled bidirectionally. It is worth pointing out that there are some reports in the literature on integrals of motion for unidirectionally coupled nonlinear Duffing oscillators, but the study carried out in this work for bidirectionally coupled systems with more than two nonlinear Duffing oscillators is certainly one of the first
Fecha (año) de inicio de la Investigación 2020
Fecha (año) de fin de la Investigación 2023
Co-autores Ernesto Urenda-Cázares 
José de Jesús Barba-Franco 
Armando Gallegos
Jorge E. Macías-Díaz
Dynamics of a ring of three fractional-order Duffing oscillators
Descripción del proyecto de Investigación We investigate the dynamics of three ring-coupled double-well Duffing oscillators modeled by fractional- order differential equations. The analysis of time series, Fourier spectra, phase portraits, Poincaré sections, and Lyapunov exponents using the fractional order and the coupling strength as control parameters, shows that the dynamics of such a system is much richer than that of the system with integer order. We demonstrate the appearance of multistability and a rotating wave when either the fractional derivative index or the coupling strength is increased, on the route from a stable steady-state regime to hyperchaos through a Hopf bifurcation and a cascade of torus bifurcations.
Fecha (año) de inicio de la Investigación 2020
Fecha (año) de fin de la Investigación 2022
Co-autores J.J. Barba-Franco, 
A. Gallegos, 
R. Jaimes-Reátegui, 
A.N. Pisarchik
Design and numerical analysis of a logarithmic scheme for nonlinear fractional diffusion-reaction equations
Descripción del proyecto de Investigación In this work, we consider a parabolic partial differential equation with fractional diffusion that generalizes the well-known Fisher’s and Hodgkin–Huxley equations. The spatial fractional derivatives are understood in the sense of Riesz, and initial–boundary conditions on a closed and bounded interval are considered here. The mathematical model is presented in an equivalent form, and a finite-difference discretization based on fractional-order centered differences is proposed. The scheme is the first explicit
logarithmic model proposed in the literature to solve fractional diffusion–reaction equations.
We rigorously establish the capability of the technique to preserve the positivity and the boundedness of the methodology. Moreover, we propose conditions under which the monotonicity of the numerical model is also preserved. The consistency, the stability and the convergence of the scheme are also proved mathematically, and some a priori bounds for the numerical solutions are proposed. We provide some numerical simulations in order to confirm that the method is capable of preserving the positivity and the boundedness of the approximations, and a numerical study of the convergence of the technique is carried out confirming, thus, the analytical results.
Fecha (año) de inicio de la Investigación 2019
Fecha (año) de fin de la Investigación 2022
Co-autores J.E. Macías-Díaz, 
A. Gallegos
Vanishing Poynting observers and electromagnetic field classification in Kerr and Kerr-Newman spacetimes. 
Descripción del proyecto de Investigación We consider electromagnetic fields having an angular momentum density in a locally non–rotating reference frame in Schwarzschild, Kerr, and Kerr-Newman spacetimes. The nature of such fields is assessed with two families of observers, the locally nonrotating ones and those of vanishing Poynting flux. The velocity fields of the vanishing-Poynting observers in the locally nonrotating reference frames are determined using the decomposition formalism. From a methodological point of view and considering a classification of the electromagnetic field based on its invariants, it is convenient to separate the consideration of the vanishing-Poynting observers into two cases corresponding to the pure and nonpure fields; additionally, if there are regions where the field rotates with the speed of light (light surfaces), it becomes necessary to split these observers into two subfamilies. We present several examples of relevance in astrophysics and general relativity, such as pure rotating dipolar-like magnetic fields and the electromagnetic field of the Kerr-Newman solution. For the latter example, we see that vanishing-Poynting observers also measure a vanishing super-Poynting vector, confirming recent results in the literature. Finally, for all nonnull electromagnetic fields, we present the 4-velocity fields of vanishing Poynting observers in an arbitrary spacetime.
Fecha (año) de inicio de la Investigación 2021
Fecha (año) de fin de la Investigación 2022
Co-autores Héctor Vargas Rodríguez
Haret Rosu
María Guadalupe Medina Guevara
Luis Armando Gallegos Infante
Miguel Angel Muñiz Torres
TEMAS SELECTOS DE MODELACIÓN Y MATEMÁTICAS APLICADAS II
Descripción del proyecto de Investigación En el primer capítulo una breve introducción al cálculo tensorial y formas diferenciales de Cartan aplicados a campos electromagnéticos rotantes, este formalismo matemático resulta ser una herramienta extremadamente útil para describir la física de cualquier sistema físico en diferentes marcos de referencia, tanto inerciales como no inerciales, este último caso da pie a poder trabajar sin problemas en relatividad general. Sin embargo, sólo nos concentramos en su aplicación a la teoría electromagnética y su clasificación en campos eléctricos, magnéticos o nulos, o bien campos puros o no puros, todo esto en términos de los invariantes relativistas que pueden ser construidos. En el segundo capítulo, presentamos uno de los primeros trabajos que desarrollamos dentro de lo que se conoce como biología matemática, particularmente el modelado estocástico del crecimiento de un glioma a partir de los niveles de glucosa en suero y cerebro. Los gliomas son los tipos de cáncer cerebral más común y más letal, por lo que cualquier herramienta que permita hacer un diagnóstico temprano puede ser de gran utilidad. El modelo consiste en un sistema de ecuaciones diferenciales ordinarias no lineales de primer orden, cuyos parámetros son perturbados con ruido estocástico con la finalidad de visualizar un efecto más real en el modelo. Se puede observar una clara influencia del sistema inmune y de la ingesta de glucosa, tanto en individuos sanos y con tumor en crecimiento conforme transcurren los años. Como ya lo hemos mencionado, el modelado matemático ha llegado incluso a los ámbitos de la sociología y en el tercer capítulo es un ejemplo de ello. Este tiene como propósito precisar estructural y formalmente un modelo de dinámica de opinión de acuerdo relativo en una sociedad mixta en términos en lo que se conoce como el protocolo ODD (Visión general, Conceptos de diseño y Detalles por sus siglas en inglés), para su mejor comprensión y facilidad de replicación. La primera parte del capítulo consiste en describir el protocolo ODD como una metodología para estandarizar el modelado basado en agentes. En la segunda parte, presentamos la implementación de dicho protocolo en la dinámica de opinión de acuerdo relativo en una sociedad mixta. El propósito del modelo es modelar y simular las opiniones en una sociedad artificial, en la que los agentes tienen perfil psicológico e incertidumbre, con la finalidad de conocer y determinar las condiciones para llegar a consensos, polarización o fragmentación en la distribución media de opinión, controlando la incertidumbre y la mezcla de perfil psicológico.
Fecha (año) de inicio de la Investigación 2020
Fecha (año) de fin de la Investigación 2022
Co-autores Norma Leticia Abrica Jacinto
Antonio Aguilera Ontiveros
Luis Enrique Ayala Hernández
Luis Armando Gallegos Infante
Ricardo Armando González Silva
Héctor Vargas Rodríguez
Dynamics of Indoctrination in Small Groups around Three Options. 
Descripción del proyecto de Investigación In this work, we consider the dynamics of opinion among three parties: two small groups of agents and one very persuasive agent, the indoctrinator. Each party holds a position different from that of the others. In this situation, the opinion space is required to be a circle, on which the agents express their position regarding three different options. Initially, each group supports a unique position, and the indoctrinator tries to convince them to adopt her or his position. The interaction between the agents is in pairs and is modeled through a system of non-linear difference equations. Agents, in both groups, give a high weight to the opinion of the indoctrinator, while they give the same weight to the opinion of their peers. Through several computational experiments, we investigate the times required by the indoctrinator to convince both groups.
Fecha (año) de inicio de la Investigación Enero, 2022
Fecha (año) de fin de la Investigación Diciembre, 2022
Co-autores María Guadalupe Medina Guevara
Evguenii Kourmyshev
Héctor Vargas Rodriguez
Optimal Combinations of Chemotherapy and Radiotherapy in Low-Grade Gliomas: A Mathematical Approach
Descripción del proyecto de Investigación Low-grade gliomas (LGGs) are brain tumors characterized by their slow growth and infiltrative nature. Treatment options for these tumors are surgery, radiation therapy and chemotherapy. The optimal use of radiation therapy and chemotherapy is still under study. In this paper, we construct a mathematical model of LGG response to combinations of chemotherapy, specifically to the alkylating agent temozolomide and radiation therapy. Patient-specific parameters were obtained from longitudinal imaging data of the response of real LGG patients. Computer simulations showed that concurrent cycles of radiation therapy and temozolomide could provide the best therapeutic efficacy in-silico for the patients included in the study. The patient cohort was extended computationally to a set of 3000 virtual patients. This virtual cohort was subject to an in-silico trial in which matching the doses of radiotherapy to those of temozolomide in the first five days of each cycle improved overall survival over concomitant radio-chemotherapy according to RTOG 0424. Thus, the proposed treatment schedule could be investigated in a clinical setting to improve combination treatments in LGGs with substantial survival benefits.
Fecha (año) de inicio de la Investigación 2019
Fecha (año) de fin de la Investigación 2021
Co-autores Luis E. Ayala-Hernández, 
Armando Gallegos, 
Philippe Schucht, 
Michael Murek,
Luis Pérez-Romasanta, 
Juan Belmonte-Beitia
Víctor M. P
érez-García
Dynamics of a ring of three unidirectionally coupled Duffing oscillators with time-dependent damping
Descripción del proyecto de Investigación We study dynamics of a ring of three unidirectionally coupled double-well Duffing
oscillators for three different values of the damping coefficient: fixed, proportional to time, and inversely proportional to time. The system dynamics in all cases are analyzed using time series, Fourier and Hilbert transforms, Poincare sections, bifurcation diagrams, and Lyapunov exponents for various coupling strengths and damping coefficients. In the first case, we observe a well known route from a stable steady state to hyperchaos through Hopf bifurcation and a series of torus bifurcations, as the coupling strength is increased. In the second case, the system is highly dissipative and converges into one of the stable equilibria. Finally, in the third case, transient toroidal hyperchaos takes place.
Fecha (año) de inicio de la Investigación 2019
Fecha (año) de fin de la Investigación 2021
Co-autores J. J. Barba-Franco, 
A. Gallegos, 
R. Jaimes-Reategui, 
S. A. Gerasimova,
A. N. Pisarchik
Driven damped nth-power anharmonic oscillators with time-dependent coefficients and their integrals of motion
Descripción del proyecto de Investigación We derive integrals of motion for general anharmonic oscillators with damping and power law forcing. The model under investigation has time-dependent coefficients, and the determination of these physical quantities is carried out using Noether’s theorem. The solutions must satisfy appropriate analytical conditions for the proposed quantities to be true integrals of motion. In turn, these analytical conditions are associated with well known physical systems, including the Milne-Pinney and Ermakov-Lewis models. We provide various numerical solutions of our equations of motion and the associated integrals to verify the theoretical results.
Fecha (año) de inicio de la Investigación 2019
Fecha (año) de fin de la Investigación 2021
Co-autores J.E. Macías-Díaz, 
E. Urenda-Cázares, 
A. Gallegos
Relativistic rotating electromagnetic fields.
Descripción del proyecto de Investigación In this work, we consider axially symmetric stationary electromagnetic fields in the framework of special relativity. These fields have an angular momentum density in the reference frame at rest with respect to the axis of symmetry; their Poynting vector form closed integral lines around the symmetry axis. In order to describe the state of motion of the electromagnetic field, two sets of observers are introduced: the inertial set, whose members are at rest with the symmetry axis; and the noninertial set, whose members are rotating around the symmetry axis. The rotating observers measure no Poynting vector, and they are considered as comoving with the electromagnetic field. Using explicit calculations in the covariant 3 + 1 splitting formalism, the velocity field of the rotating observers is determined and interpreted as that of the electromagnetic field. The considerations of the rotating observers split in two cases, for pure fields and impure fields, respectively. Moreover, in each case, each family of rotating observers splits in two subcases, due to regions where the electromagnetic field rotates with the speed of light. These regions are generalizations of the light cylinders found around magnetized neutron stars. In both cases, we give the explicit expressions for the corresponding velocity fields. Several examples of relevance in astrophysics and cosmology are presented, such as the rotating point magnetic dipoles and a superposition of a Coulomb electric field with the field of a point magnetic dipole.
Fecha (año) de inicio de la Investigación 2017
Fecha (año) de fin de la Investigación 2020
Co-autores Héctor Vargas Rodríguez
Luis Armando Gallegos Infante
Miguel Angel Muñiz Torres
Haret Rosu
Paulino Javier Domínguez Chávez
Effects of multiplicative noise on the Duffing oscillator with variable coefficients and its integral of motion
Descripción del proyecto de Investigación In this work, we implement multiplicative noise to the Duffing oscillator with variable coefficients. The stochastic differential equations are solved using the fourth-order Runge–Kutta method with the Box-Müller algorithm and the corresponding integral of motion is obtained. Some numerical experiments are performed and the results show that the integral of motion is highly unaffected by the multiplicative noise.
Fecha (año) de inicio de la Investigación 2018
Fecha (año) de fin de la Investigación 2020
Co-autores E. Urenda-Cazares, 
A. Gallegos
R. Jaimes-Reátegui
A mathematical model that combines chemotherapy and oncolytic virotherapy as an alternative treatment against a glioma
Descripción del proyecto de Investigación In this paper, we propose a mathematical model that combines chemotherapy and oncolytic virotherapy as an alternative to treatment of a glioma. The main idea is to incorporate the virotherapy after the first or second chemotherapy session using a specialist virus that attacks only tumor cells. Some simulations are presented. Based on the results, we conclude that this combined therapy may reduce the number of chemotherapy sessions and may lead to obtain better results in the fight against gliomas.
Fecha (año) de inicio de la Investigación 2018
Fecha (año) de fin de la Investigación 2020
Co-autores E. Urenda-Cázares
A. Gallegos
J. E. Macías-Díaz
An integral of motion for the damped cubic-quintic Duffing oscillator with variable coefficients
Descripción del proyecto de Investigación Integrals of motion for the undamped and damped cubic- quintic Duffing oscillators with time-dependent coefficients are obtained for the first time in the literature under appropriate analytical conditions. The integrals of motion are obtained using Noether’s theorem, and the conditions for their existence are directly related to the well-known Milne–Pinney equation, which is associated with the Ermakov-Lewis systems. We perform here some numerical simulations to illustrate the validity of our analytical results.
Fecha (año) de inicio de la Investigación 2017
Fecha (año) de fin de la Investigación 2019
Co-autores E. Urenda-Cázares, 
A. Gallegos, 
J.E. Macías-Díaz, 
H. Vargas-Rodríguez
On a positivity-preserving numerical model for a linearized hyperbolic Fisher–Kolmogorov–Petrovski–Piscounov equation
Descripción del proyecto de Investigación We introduce a nonstandard finite-difference scheme to approximate positive solutions of a modified hyperbolic Fisher–Kolmogorov–Petrovski–Piscounov equation appearing in the investigation of the dynamics of some populations. The technique has a consistency of second order, and it provides nonnegative approximations for nonnegative initial profiles. The stability analysis of the method is carried out in detail, and the scheme is validated against known analytical solutions for some initial–boundary-value problems
Fecha (año) de inicio de la Investigación 2017
Fecha (año) de fin de la Investigación 2019
Co-autores J.E. Macías-Díaz, 
Armando Gallegos
A mathematical model for the pre-diagnostic of glioma growth based on blood glucose levels
Descripción del proyecto de Investigación We propose a stochastic model in which the values of the factors involved in the development of a glioma vary randomly in a biologically congruent range. Stability analysis revealed three fixed points which allude to patients with a growing glioma, with an advanced stage glioma and without glioma, respectively. The graphics of the solutions and the diagrams of asymptotic behavior of some of the parameters are presented. We also show the order of influence of them. The results obtained show a decay in serum glucose levels in the presence of a glioma.Moreover, they indicate that the immune system is an important element in the prevention of the growth of glioma.
Fecha (año) de inicio de la Investigación 2016
Fecha (año) de fin de la Investigación 2018
Co-autores L. E. Ayala-Hernández
Armando Gallegos
J. E. Macías-Díaz 
M. L. Miranda-Beltrán
H. Vargas-Rodríguez
Evolution of electoral preferences for a regime of three political parties. 
Descripción del proyecto de Investigación  
Fecha (año) de inicio de la Investigación octubre 2017
Fecha (año) de fin de la Investigación 24 de octubre de 2018
Co-autores Maria Guadalupe Medina  Guevara
Héctor Vargas Rodríguez
Pedro Basilio Espinoza Padilla
José Luis González Solís
Superenergy flux of Einstein–Rosen waves. 
Descripción del proyecto de Investigación In this work, we consider the propagation speed of the superenergy flux associated to the Einstein–Rosen cylindrical waves propagating in vacuum and over the background of the gravitational field of an infinitely long mass line distribution. The velocity of the flux is determined considering the reference frame in which the super-Poynting vector vanishes. This reference frame is then considered as comoving with the flux. The explicit expressions for the velocities are given with respect to a reference frame at rest with the symmetry axis.
Fecha (año) de inicio de la Investigación 2015
Fecha (año) de fin de la Investigación 2018
Co-autores Paulino Javier Dominguez Chávez
Luis Armando Gallegos Infante
Jorge Eduardo Macías Díaz
Héctor Vargas Rodríguez
Comment on demystifying the constancy of the Ermakov Lewis invariant for a time-dependent oscillator
Descripción del proyecto de Investigación We show that a simple modification of the Lagrangian proposed by Padmanabhan in
the paper [Mod. Phys. Lett. A 33, 1830005 (2018)] leads to the most general dynamical
invariant in [Ray and Reid, Phys. Lett. A 71, 317 (1979)].
Fecha (año) de inicio de la Investigación 2018
Fecha (año) de fin de la Investigación 2018
Co-autores A. Gallegos
H. C. Rosu
A finite‐difference model for indoctrination dynamics. 
Descripción del proyecto de Investigación In this work, a system of non‐linear difference equations is employed to model the opinion dynamics between a small group of agents (the target group) and a very persuasive agent (the indoctrinator). Two scenarios are investigated: the indoctrination of a homogeneous target group, in which each agent grants the same weight to his (or her) partner's opinion and the indoctrination of a heterogenous target group, in which each agent may grant a different weight to his or her partner's opinion. Simulations are performed to study the required times by the indoctrinator to convince a group. Initially, these groups are in a consensus about a doctrine different to that of the ideologist. The interactions between the agents are pairwise.
Fecha (año) de inicio de la Investigación Enero 2018
Fecha (año) de fin de la Investigación Noviembre 2018
Co-autores María Guadalupe Medina Guevara
Héctor Vargas Rodríguez
Pedro Basilio Espinoza Padilla
On S1 as an alternative continuous opinion space in a three-party regime.
Descripción del proyecto de Investigación In this work, we propose a discrete system to model the dynamics of individual opinions when the agents of a population have three equally likely choices. The social network consists of a finite number of agents with pairwise interactions at discrete times, and the opinion space is identified as a triangle in the plane. After a suitable homotopic transformation, one may convert the opinion space into the classical circle  of the Cartesian plane. The opinion of each agent is updated following a general nonlinear law which considers individual parameters of the members. We establish conditions that guarantee the existence of attracting points (or strong consensus), and infer the existence of attracting intervals (identified here as weak consensus). Moreover, we notice that the conditions that lead to global consensuses are independent of the weight matrix and the number of agents in the network. The simulations obtained in this work confirm the validity of the analytical results.
Fecha (año) de inicio de la Investigación Diciembre 2015
Fecha (año) de fin de la Investigación Septiembre de 2016
Co-autores María Guadalupe Medina Guevara
Jorge Eduardo Macías Diáz
Luis Armando Gallegos Infante
Héctor Vargas Rodríguez