Using the time-dependent wave function we have studied the properties of the atomic transverse motion in an interferometer, and the cause of the non-classical behavior of atoms reported by Kurtsiefer, Pfau, and Mlynek [Nature 386, 150 (1997)]. The transverse wave function is derived from the solution of the two-dimensional Schrödinger's equation, written in the form of the Fresnel–Kirchhoff diffraction integral. It is assumed that the longitudinal motion is classical. Comparing data of the space distribution and of the transverse momentum distribution (...) in interferometers with one and two open slits, it follows that the atomic motion is influenced by the atomic matter wave and violates the laws of classical mechanics. However, the negative values of Wigner's function should not be taken as evidence that the atoms in an interferometer violate the classical statistical law of the addition of positive probabilities. This inference follows from the comparison of properties of Wigner's function and of the de Broglian probability density in phase space. (shrink)

El ejercicio filosófico de raíz marxista en Chile tiene un capítulo escrito por los intelectuales comunistas de la década del 60 del siglo XX. Uno de ellos, Sergio Vuskovic, se abocó a discutir con las tesis althusserianas que identificaron la teorización de Marx como un antihumanismo teórico. Para oponerse a tal perspectiva, Vuskovic realiza una operación teórica al interior de la obra de Marx con el objetivo de afirmar la categoría de sujeto, así como la interna relación entre (...) ejercicio teórico y praxis socio-histórica. Chilean communist intellectuals of the 1960's wrote a chapter of the history of Marxist philosophy. One of them was Sergio Vuskovic who focused on discussing Marx's theories according to Althusser's thesis of anti-humanism. By affirming the subject category and the internal relationship between "theoretical operation" and socio-historical praxis within Marx's philosophy, Vuskovic opposes Althusser's perspective. (shrink)