Buscar
Mostrando ítems 21-30 de 164
A Geometric Splitting Theorem
(2019)
Let G = G1...Gl be a connected noncompact semisimple
Lie group with Lie algebra g = g_1+g_2+....+ g_l acting topologically
transitive on a manifold M. We obtain a geometric splitting
of the metric on M that consider ...
Quadratic Hamiltonians in phase-space quantum mechanics
(1989-07)
The dynamical evolution is described within the phase-space
formalism by means of the Moyal propagator, which is the symbol of the
evolution operator. Quadratic Hamiltonians on the phase space are
distinguished in that ...
Quantum gauge models without classical Higgs mechanism
(2010-09-15)
We examine the status of massive gauge theories, such as those usually obtained by spontaneous symmetry breakdown, from the viewpoint of causal (Epstein-Glaser) renormalization. The BRST formulation of gauge invariance in ...
A nonperturbative form of the spectral action principle in noncommutative geometry
(1998-07)
Using the formalism of superconnections, we show the existence of a bosonic action functional for the standard K-cycle in noncommutative geometry, giving rise, through the spectral action principle, only to the Einstein ...
Improved Epstein-Glaser renormalization in x-space versus differential renormalization
(2014-09)
Renormalization of massless Feynman amplitudes in x-space is reexamined here, using almost exclusively real-variable methods. We compute a wealth of concrete examples by means of recursive extension of distributions. This ...
The Impact of Help-Seeking for Depression: A Mathematical Model
(2022)
For years and with the Covid-19 pandemic, mental illnesses such as depression have emerged. According to the World Health Organization, an average of 5\% of the population in a country suffers from depression. The ...
Modeling the university drinking culture phenomenon
(2022-11-03)
We study a susceptible-drinker-recovered (SDR) model for the drinking culture phenomenon in university atmospheres. We find conditions for this model to have extinction and endemic equilibrium points. We analyze different ...
A two-patch epidemic model with nonlinear reinfection
Un modelo epidémico de dos poblaciones con reinfección no lineal
(2020)
The propagation of infectious diseases and its impact on individuals play a major role in disease dynamics, and it is important to incorporate population heterogeneity into efforts to study diseases. As a simplistic but ...
Área y multiplicación
(1990)
Mostramos que la fórmula “área de un rectángulo de base b y altura h = b.h” surge de las propiedades exigidas al concepto “área de un rectángulo” en la actividad de los colectivos humanos, las que quedaron reflejadas en ...
Equilibrium states for maps isotopic to Anosov
(2021)
In this work we address the problem of existence and uniqueness (finiteness) of ergodic equilibrium states for partially hyperbolic diffeomorphisms isotopic to Anosov on T4, with two-dimensional center foliation. To do so ...