2,526 research outputs found
The Adiabatic Theorem for Quantum Systems with Spectral Degeneracy
By stating the adiabatic theorem of quantum mechanics in a clear and rigorous
way, we establish a necessary condition and a sufficient condition for its
validity, where the latter is obtained employing our recently developed
adiabatic perturbation theory. Also, we simplify further the sufficient
condition into a useful and simple practical test at the expenses of its
mathematical rigor. We present results for the most general case of quantum
systems, i.e., those with degenerate energy spectra. These conditions are of
upmost importance to assess the validity of practical implementations of
non-Abelian braiding and adiabatic quantum computation. To illustrate the
degenerate adiabatic approximation, and the necessary and sufficient conditions
for its validity, we analyze in depth an exactly solvable time-dependent
degenerate problem.Comment: 4 pages, no figures, RevTex4-1; v2: published versio
El problema de la validación de conocimientos en la sociología
En una primara parte, introduciré el problema enunciado en el título de esta comunicación valiéndome del análisis del término validación, lo haré en función de los usos que el mismo tiene en contextos lingüísticos específicos. Inmediatamente, diré algo acerca de cómo la validez o validación de conocimientos en ciencia social (que de eso se trata en nuestro caso), pertenecen al área de la filosofía que algunos llaman epistemología y otros metodología. Por último -y siempre dentro de esa primera parte- añadiré un par de reflexiones acerca de la relación entre la fundamentación y la validación de conocimientos
Adiabatic Perturbation Theory and Geometric Phases for Degenerate Systems
We introduce an adiabatic perturbation theory for quantum systems with
degenerate energy spectra. This perturbative series enables one to rigorously
establish conditions for the validity of the adiabatic theorem of quantum
mechanics for degenerate systems. The same formalism can be used to find
non-adiabatic corrections to the non-Abelian Wilczek-Zee geometric phase. These
corrections are relevant to assess the validity of the practical implementation
of the concept of fractional exchange statistics. We illustrate the formalism
by exactly solving a time-dependent problem and comparing its solution to the
perturbative one.Comment: 5 pages, no figures, RevTex4; v2: published versio
Baryon spectroscopy in the unquenched quark model
We discuss some applications of the unquenched quark model which is an
extension of the CQM that includes the effects of sea quarks via a 3P0
quark-antiquark pair-creation mechanism. Particular attention is paid to the
electromagnetic couplings and beta decays of baryons. It is shown that the
observed discrepancies between the experimental data and the predictions of the
CQM can be accounted for in large part by the effects of sea quarks in the
unquenched quark model.Comment: 5 pages, 2 figures, 2 tables, invited talk at XVII International
Conference on Hadron Spectroscopy and Structure, submitted for publication in
Proceedings of Scienc
The issue of social politicization in García Linera
Álvaro García Linera, es uno de los líderes políticos más importantes de la región, cuyo
pensamiento y praxis política en Bolivia, nos permite analizar las causas y consecuencias del
regreso de un nuevo oleaje neoliberal en latinoamérica.
El intelectual ha propuesto la mirada crítica sobre las debilidades de los gobiernos progresistas
de inicios de la presente década, y una de ellas, la que será objeto de esta investigación, refiere
que la distribución de riqueza pública es ineficiente sin la politización social de las sociedades
o comunidades.
Descubriremos través de un recorrido de sus publicaciones académicas y entrevistas realizadas,
los rasgos teóricos y empíricos de politicidad, señalando las experiencias bolivianas de la
nación indígena Aymará como de otras iniciativas colectivas como Multitud; examinando
además, los argumentos por el cuál es necesario superar el sentido común conservador, en el
marco de la lucha por la hegemonía cultural.Álvaro García Linera, is one of the most important political leaders in the region, whose thought
and political praxis in Bolivia, allows us to analyze the causes and consequences of the return
of a new neoliberal wave in latin América.
The intellectual has proposed a critical look at the weaknesses of the progressive governments
of the beginning of this decade, and one of them, which will be the subject of this research,
refers that the distribution of public wealth is inefficient without politicization Society or
communities.
We will discover through a tour of their academic publications and interviews, the theoretical
and empirical features of politicity, pointing out the Bolivian experiences of the Aymara
Indigenous nation as well as other collective initiatives as a multitude; further examining the
arguments for which it is necessary to overcome conservative common sense in the context of
the struggle for cultural hegemony.Fil: Ortiz, Gustavo David.
Universidad Nacional de Cuy
- …