The differential-algebraic and bi-Hamiltonian integrability analysis of the Riemann type hierarchy revisited

A differential-algebraic approach to studying the Lax type integrability of the generalized Riemann type hydrodynamic hierarchy is revisited, its new Lax type representation and Poisson structures constructed in exact form. The related bi-Hamiltonian integrability and compatible Poissonian structures of the generalized Riemann type hierarchy are also discussed.Comment: 18 page

Differential-Algebraic Integrability Analysis of the Generalized Riemann Type and Korteweg-de Vries Hydrodynamical Equations

A differential-algebraic approach to studying the Lax type integrability of the generalized Riemann type hydrodynamic equations at N = 3; 4 is devised. The approach is also applied to studying the Lax type integrability of the well known Korteweg-de Vries dynamical system.Comment: 11 page

Nonlinear Spin Dynamics in Nuclear Magnets

A method is developed for solving nonlinear systems of differential, or integrodifferential, equations with stochastic fields. The method makes it possible to give an accurate solution for an interesting physical problem: What are the peculiarities of nonlinear spin dynamics in nonequilibrium nuclear magnets coupled with a resonator? Evolution equations for nuclear spins are derived basing on a Hamiltonian with dipole interactions. The ensemble of spins is coupled with a resonator electric circuit. Seven types of main relaxation regimes are found: free induction, collective induction, free relaxation, collective relaxation, weak superradiance, pure superradiance, and triggered superradiance. The initial motion of spins can be originated by two reasons, either by an imposed initial coherence or by local spin fluctuations due to nonsecular dipole interactions. The relaxation regimes caused by the second reason cannot be described by the Bloch equations. Numerical estimates show good agreement with experiment.Comment: 1 file, 47 pages, LaTe

The features of the non-equilibrium equation of state in heavy-ion collisions at intermediate energies

Section IV. Nuclear Reactions Theor

Imaginarios cimarrones: Orígenes de la cosmovisión y prácticas mágico-religiosas de los afroesmeraldeños

This article analyzes how historical and sociocultural factors in Esmeraldas province, Ecuador, during the colonial era influenced the preservation of the worldview and magical-religious practices of african origin in the afroesmeraldeños. In this sense, we have identified three factors of influence -maroonage, road isolation and oral tradition-, which led that afroesmeraldeños´ worldview and magical-religious practices are the result of intensive transculturation which includes the hispanic and indigenous, but in which one can see deep african imaginaries. Este artículo analiza qué factores históricos y socioculturales existentes durante la etapa colonial en la provincia de Esmeraldas, Ecuador, influyeron en la preservación de la cosmovisión y las prácticas mágico-religiosas de origen africano en los afroesmeraldeños. En este sentido, se han determinado tres factores de influencia —el cimarronaje, el aislamiento vial y la tradición oral—, los cuales motivaron que la cosmovisión y las prácticas mágico-religiosas de los afroesmeraldeños sean fruto de una intensa transculturación que incluye lo hispánico y lo indígena, pero en la que es posible apreciar profundos imaginarios de origen africano