Universality of quantum Brownian motion

Are Markovian master equations for quantum Brownian motion independent of model assumptions used in the derivation and, thus, universal? With the aim of answering this question, we use a random band-matrix model for the system-bath interaction to derive Markovian master equations for the time evolution of one-dimensional quantum systems weakly coupled to a heat bath. We study in detail two simple systems, the harmonic oscillator and the two-level system. Our results are in complete agreement with those of earlier models, like the Caldeira-Legget model and, in the large-band limit, with the Agarwal equations (both with and without rotating-wave approximation). This proves the universality of these master equations.Comment: 24 page

ELECTRONIC STATES IN GRADED-GAP JUNCTIONS WITH BAND INVERSION

We theoretically study electronic states in graded-gap junctions of IV-VI compounds with band inversion. Using a two-band model within the ${\bf k}\cdot{\bf p}$ approximation and assuming that the gap and the gap centre present linear profiles, we demonstrate the existence of a set of localized states along the growth direction with a discrete energy spectrum. The envelope functions are found to be combination of harmonic oscillator eigenfunctions, and the corresponding energy levels are proportional to the square root of the quantum number. The level spacing can be directly controlled by varying the structure thickness.Comment: REVTEX 3.0, 7 pages, no figures, to appear in Phys. Lett.

Historias de viajeros y trashumantes: el Presbítero J. Holartes

Este documento rescata un manuscrito de origen incierto, en el cuál se describe un tramo de la vida de un religioso muy cercano, tanto en su espíritu cómo a través de sus escritos, al vasto mundo de la Ictiología Neotropical. La calificación de “origen incierto” a este documento, se basa en que, en nuestros archivos, no hemos encontrado ninguna referencia sobre el autor; sí sobre P. J. Holartes (ver López et al., 1981), así como la existencia de objetos artesanales que testimonian la presencia de este domínico en el centro y NO de nuestro país. Sólo podemos especular que su paso por el Valle de Traslasierra no sería casual, ya que seguramente, entre sus objetivos estaba el reunirse con el hoy beato J. G. Brochero. Nosotros pensamos, quizás sin demasiados fundamentos, que Clementino Agassi es un pseudónimo utilizado para plasmar este relato intemporal, ya que como dijo Henri Bergson “El tiempo es invención o no es nada en absoluto

Verisimilitude

La idea de la verosimilitud está implícita en los escritos de Albert Einstein, desde 1905. La noticia ha llegado a  la comunidad filosófica a través de los escritos de Sir Karl Popper, medio siglo después de la concepción  pionera de Einstein. Como la teoría de la verosimilitud es de por sí pro-metafísica, hay dos posibles lecturas  de la visión popperiana de la verosimilitud. Creo que las críticas que ha recibido se deben a su vaguedad  sobre esta cuestión, y a las limitaciones obvias de admitir, a medias, la metafísica en la ciencia. A pesar que la verosimilitud esta recién llegada a la física moderna, ya cuenta con una rica literatura, incluyendo el libro  Truthlikeness de Ilkka Niiniluoto, el más enérgico defensor del tema. El presente artículo no es una reseña de dicho libro, debido a que la mera discusión de su enorme y pesado aparato lógico-matemático requiere más  espacio del que está disponible aquí. Sin embargo, diré que su libro ha demostrado ser un hito filosófico - para bien o para mal- y trataré de presentar los aspectos filosóficos más generales de la situación. Debo  aclarar que no intentaré suprimir mi sesgo, sino contrastarlo con el suyo. En pocas palabras, creo que su  posición está a medio camino en favor de la metafísica, mientras que la mía es totalmente pro-metafísica. Sin importar los avances que la teoría de la verosimilitud ha logrado desde entonces, el desacuerdo aquí descrito no es efímero, y mi punto de vista me ha llevado a una perspectiva de la verosimilitud, que se opone a casi  todo lo que se ha escrito después del mencionado libro de Niiniluoto de 1987.The idea of verisimilitude is implicit in the writings of Albert Einstein ever since 1905. The news has reached  the philosophical community via the writings of Sir Karl Popper half-acentury after Einstein’s trailblazing  conception. As the theory of verisimilitude is inherently pro-metaphysics, there are two possible readings of  Popper’s view of verisimilitude. I think the criticisms that it has met are due to his vagueness on this matter  and to the obvious shortcomings of the halfway admission of metaphysics into science. Though  verisimilitude is a relative newcomer to the modern physics, it already has a rich literature, including the  book Truthlikeness of Ilkka Niiniluoto, the most energetic advocate of the topic. The present article is not a  review of it, as the mere discussion of its enormous, heavy logical mathematical apparatus requires more  space than is available to me. I will, however, say that his book has proven to be a philosophical landmark - for better and for worse- and I will try to present the general, most philosophical aspects of the situation. I  should say here that I am not going to suppress my bias but rather contrast it with his. Briefly, I think that his  position is halfway pro-metaphysical whereas mine is fully pro-metaphysical. Whatever advances the theory  of verisimilitude has made since, the disagreement here outlined is not ephemeral, and my view has led me  to a specific view of verisimilitude that is at odds with almost all that has been written after Niiniluoto’s  mentioned book of 1987

Relationship between talent development, work environment, pay benefits and job satisfaction / Agassi Cantona Johnson

The objective of this study was to find out whether independent variables which were work environment, pay benefits and talent development have a positive relationship with the selected dependent variable, job satisfaction. The study also targeted respondents who currently working in construction sector which was employees of Sri Pengkalan Binaan’s group of employees been selected. The collected data of the study were analyzed using Statistical Package for Social Science (SPSS) software. The response rate of the respondents was 94.2% where 81 out of 86 respondents successfully return their questionnaires. Various types of analysis and tests had been conducted which is was consists of descriptive analysis, reliability test, correlation analysis, and multiple regression analysis. All of these analysis and tests was to study the data that have been collected. The study portrait that only one independent variable has a significant effect on job satisfaction which is working environment. While the other two independent variables (pay benefits and talent development) did not have significant effect on job satisfaction

Role of non-collective excitations in heavy-ion fusion reactions and quasi-elastic scattering around the Coulomb barrier

Despite the supposed simplicity of double-closed shell nuclei, conventional coupled-channels calculations, that include all of the known collective states of the target and projectile, give a poor fit to the fusion cross section for the $^{16}$O + $^{208}$Pb system. The discrepancies are highlighted through the experimental barrier distribution and logarithmic derivative, that are both well defined by the precise experimental fusion data available. In order to broaden our search for possible causes for this anomaly, we revisit this system and include in our calculations a large number of non-collective states of the target, whose spin, parity, excitation energy and deformation paramter are known from high-precision proton inelastic-scattering measurements. Although the new coupled-channels calculations modify the barrier distribution, the disagreemnt with experiment remains both for fusion and for quasi-elastic (QE) scattering. We find that the Q-value distributions for large-angle QE scattering become rapidly more important as the incident energy increases, reflecting the trend of the experimental data. The mass-number dependence of the non-collective excitations is discussed.Comment: 8 pages, 7 figure

Playing the Game of International Law

In the realist game of international negotiations, each state attempts to promote their interest regardless of international law. Thus, it is negotiations in the shadow of the sword, i.e., a negotiation in which each side knows that if the parties will not achieve an agreement, the alternative may be a war, and thus the bargaining position of each party is a function of their capacities in a case of war. Negotiation in the shadow of international law is an alternative to it: in this alternative the parties negotiate according to their international legal rights. It reduces injustice and incentive to armament and to terror. It thus promotes peace. A state can choose unilaterally to play the game of negotiations in accord with international law by merely respecting the rights of one’s neighbours regardless to their waving swords, and by this have much more peace and generate incentives against terror and armament. This efficiently brings much more security and peace. A policy of respecting international law, combined with conditional generosity, is more efficient. The wish for peace should make a country encourage its neighbours to avoid armament. The best way to do so is to adopt a policy of unilateral respect for international law and conditional generosity towards one’s neighbours. The international community should enforce, or at least encourage, negotiations in accord with international law