Dynamics of Coherent States in Regular and Chaotic Regimes of the Non-integrable Dicke Model

The quantum dynamics of initial coherent states is studied in the Dicke model and correlated with the dynamics, regular or chaotic, of their classical limit. Analytical expressions for the survival probability, i.e. the probability of finding the system in its initial state at time $t$, are provided in the regular regions of the model. The results for regular regimes are compared with those of the chaotic ones. It is found that initial coherent states in regular regions have a much longer equilibration time than those located in chaotic regions. The properties of the distributions for the initial coherent states in the Hamiltonian eigenbasis are also studied. It is found that for regular states the components with no negligible contribution are organized in sequences of energy levels distributed according to Gaussian functions. In the case of chaotic coherent states, the energy components do not have a simple structure and the number of participating energy levels is larger than in the regular cases.Comment: Contribution to the proceedings of the Escuela Latinoamericana de F\'isica (ELAF) Marcos Moshinsky 2017. (9 pages, 4 figures

Effects of three-body collisions in a two-mode Bose-Einstein condenstate

We study the effects of three-body collisions in the basic physical properties of a two-mode Bose-Einstein condensate. By finding the exact analytical solution of a model which includes two-body and three-body elastic and mode-exchange collisions, we show analytically that three-body interactions produce observable effects in the probability distribution of the ground state and the dynamics of the relative population. In particular, we find that three-body interactions under certain circumstances inhibit collapse of the relative population.Comment: 5 pages, 3 figures. I.F. previously published as I. Fuentes-Schuller and I. Fuentes-Guridi. v2:minor changes, published versio

Hydrogen and muonium in diamond: A path-integral molecular dynamics simulation

Isolated hydrogen, deuterium, and muonium in diamond have been studied by path-integral molecular dynamics simulations in the canonical ensemble. Finite-temperature properties of these point defects were analyzed in the range from 100 to 800 K. Interatomic interactions were modeled by a tight-binding potential fitted to density-functional calculations. The most stable position for these hydrogenic impurities is found at the C-C bond center. Vibrational frequencies have been obtained from a linear-response approach, based on correlations of atom displacements at finite temperatures. The results show a large anharmonic effect in impurity vibrations at the bond center site, which hardens the vibrational modes with respect to a harmonic approximation. Zero-point motion causes an appreciable shift of the defect level in the electronic gap, as a consequence of electron-phonon interaction. This defect level goes down by 70 meV when replacing hydrogen by muonium.Comment: 11 pages, 8 figure

Los derechos fundamentales en el Siglo XXI. Implicancias en algunas cuestiones relativas al Derecho del Consumidor y Sucesorio en Argentina, analizadas a través de sentencias judiciales

This study gives an account of the so-called process of constitutionalization of Private Law in Argentina, and the relevance of fundamental and human rights in civil, commercial and consumer relations. Emphasis is placed on the methodological change that this implies for the construction of legal responses, and focuses on some aspects related to Consumer Law -especially punitive damage-, and different issues and institutions that project their effects on Inheritance Law. , in particular, socio-affectivity, the real right of habitation and postmortem fertilization. The work gives an account of recent judicial decisions, and problems of Transitory Law.  El presente estudio da cuenta del llamado proceso de constitucionalización del Derecho Privado en Argentina, y de la relevancia de los derechos fundamentales y humanos en las relaciones civiles, comerciales y de consumo. Se pone el acento en el cambio metodológico que ello supone para la construcción de las respuestas jurídicas, y se centra en algunos aspectos vinculados al Derecho del Consumidor –especialmente el daño punitivo-, y diferentes cuestiones e instituciones que proyectan sus efectos sobre el Derecho Sucesorio, en particular, la socioafectividad, el derecho real de habitación y la fertilización postmortem. El trabajo da cuenta de decisiones judiciales recientes, y de problemas de Derecho Transitorio.&nbsp

La transmisión de virus no persistentes estudiada a través del comportamiento de prueba de pulgones

Cinco años de investigación sobre el comportamiento de prueba del pulgón Myzus persicae Sulzer con la ayuda de un monitor electrónico de comportamiento (técnica EPG) han permitido obtener un mejor conocimiento sobre el mecanismo de transmisión no persistente de virus vegetales, empleando como modelo el virus Y de la patata (PVY). Las breves picaduras intracelulares producidas por el pulgón al inicio de la prueba son registradas en el monitor electrónico como breves caídas de potencial (denominadas pds). La presencia y morfología de este patrón de onda pd ha resultado ser clave en el proceso de tranmisión de PVY. Se ha observado que la presencia de al menos una pd es necesaria para la adquisición del virus, y que una mayor frecuencia de pds aumenta la probabilidad de adquisición. Asimismo, se ha comprobado que el proceso de inoculación del virus también tiene lugar durante la pd, más en concreto en su fase inicial III, mientras que la adquisición es un proceso posterior (fase 113). Esta evidencia pone en duda el mecanismo mayoritariamente aceptado de ingestión-egestión, proponiéndose como hipótesis alternativa un mecanismo de ingestión-salivación. Asimismo, la presencia y morfología de la fase 113 de la pd ha proporcionado una explicación satisfactoria al conocido efecto del ayuno previo (que aumenta la eficiencia de transmisión) y a la distinta capacidad vectorial observada en diferentes especies de pulgone

Congenital fiber-type disproportion myopathy: a case study

Congenital fiber-type disproportion myopathy causes impaired muscle maturation or development. It is characterized by moderate to severe hypotonia and generalized muscle weakness at birth or during the first year of life, especially in the lower extremities. It is inherited as an autosomal recessive, dominant and X-linked. It is diagnosed by clinical data confirmation, generalized hypotonia and a muscle biopsy in which muscle fibers type I are smaller in caliber, 12% smaller than those of type II and type I fibers are more common than type II. Treatment is multidisciplinary. The following describes the case of a patient who was born in the ‘‘Dr. José Eleuterio González’’ University Hospital in Monterrey, N.L, who presented clinical and muscle biopsy compatible with this myopathy

Canal dehiscence syndrome of the superior semicircular: In a case purpose

Indexación: Web of Science; ScieloEl síndrome de dehiscencia de canal semicircular superior (DCSS) es una patología descrita en 1998 por Minor y cols, presenta síntomas diversos incluido vértigo inducido por el sonido, hipoacusia y autofonía por la falta de cobertura ósea en dicho canal. El diagnóstico se basa en la clínica y la confirmación se obtiene mediante la tomografía computarizada de peñasco. El tratamiento será expectante o reparación quirúrgica de la continuidad si la clínica es incapacitante. En este artículo se presenta un caso clínico de DCSS con síntomas auditivos y vestibulares al emitir el fonema "mmm".The superior semicircular dehiscence síndrome is a pathology described en 1998 by Minor et al. Which presents several symptoms incluid sound induced vértigo, hearing loss and autophony due to bone dehiscense of this semicircular canal. The diagnosis was based on clinical and confirmation is given by the temporal bone CT. Treatment is expectant or surgical repair of continuity if the clinic is disabling. In this paper we present a case of DCSS with auditory and vestibular symptoms in issuing the phoneme "mmm".http://ref.scielo.org/jbys2

Etiopathology of chronic tubular, glomerular and renovascular nephropathies: Clinical implications

Chronic kidney disease (CKD) comprises a group of pathologies in which the renal excretory function is chronically compromised. Most, but not all, forms of CKD are progressive and irreversible, pathological syndromes that start silently (i.e. no functional alterations are evident), continue through renal dysfunction and ends up in renal failure. At this point, kidney transplant or dialysis (renal replacement therapy, RRT) becomes necessary to prevent death derived from the inability of the kidneys to cleanse the blood and achieve hydroelectrolytic balance. Worldwide, nearly 1.5 million people need RRT, and the incidence of CKD has increased significantly over the last decades. Diabetes and hypertension are among the leading causes of end stage renal disease, although autoimmunity, renal atherosclerosis, certain infections, drugs and toxins, obstruction of the urinary tract, genetic alterations, and other insults may initiate the disease by damaging the glomerular, tubular, vascular or interstitial compartments of the kidneys. In all cases, CKD eventually compromises all these structures and gives rise to a similar phenotype regardless of etiology. This review describes with an integrative approach the pathophysiological process of tubulointerstitial, glomerular and renovascular diseases, and makes emphasis on the key cellular and molecular events involved. It further analyses the key mechanisms leading to a merging phenotype and pathophysiological scenario as etiologically distinct diseases progress. Finally clinical implications and future experimental and therapeutic perspectives are discussed

Adiabatic invariants for the regular region of the Dicke model

Adiabatic invariants for the non-integrable Dicke model are introduced. They are shown to provide approximate second integrals of motion in the energy region where the system exhibits a regular dynamics. This low-energy region, present for any set of values of the Hamiltonian parameters is described both with a semiclassical and a full quantum analysis in a broad region of the parameter space. Peres lattices in this region exhibit that many observables vary smoothly with energy, along distinct lines which beg for a formal description. It is demonstrated how the adiabatic invariants provide a rationale to their presence in many cases. They are built employing the Born-Oppenheimer approximation, valid when a fast system is coupled to a much slower one. As the Dicke model has one bosonic and one fermionic degree of freedom, two versions of the approximation are used, depending on which one is the faster. In both cases a noticeably accord with exact numerical results is obtained. The employment of the adiabatic invariants provides a simple and clear theoretical framework to study the physical phenomenology associated to these regimes, far beyond the energies where a quadratic approximation around the minimal energy configuration can be used