Reversible and irreversible evolution of a condensed bosonic gas

We have formulated a kinetic theory for a condensed atomic gas in a trap, i.e., a generalized Gross-Pitaevskii equation, as well as a quantum-Boltzmann equation for the normal and anomalous fluctuations [R. Walser et al., Phys. Rev. A, 59, 3878 (1999)]. In this article, the theory is applied to the case of an isotropic configuration and we present numerical and analytical results for the reversible real-time propagation, as well as irreversible evolution towards equilibrium.Comment: 15 pages RevTeX, 8 figures, reviewed PRA resubmissio

Quantum Kinetic Theory for a Condensed Bosonic Gas

We present a kinetic theory for Bose-Einstein condensation of a weakly interacting atomic gas in a trap. Starting from first principles, we establish a Markovian kinetic description for the evolution towards equilibrium. In particular, we obtain a set of self-consistent master equations for mean fields, normal densities, and anomalous fluctuations. These kinetic equations generalize the Gross-Pitaevskii mean-field equations, and merge them consistently with a quantum-Boltzmann equation approach.Comment: 15 pages, no figures; reviewed version; to be published in PR

Quasi-Experiments in Schools: The Case for Historical Cohort Control Groups

There is increased emphasis on using experimental and quasi-experimental methods to evaluate educational programs; however, educational evaluators and school leaders are often faced with challenges when implementing such designs in educational settings. Use of a historical cohort control group design provides a viable option for conducting quasi-experiments in school-based outcome evaluation. A cohort is a successive group that goes through some experience together, such as a grade level or a training program. A historical cohort comparison group is a cohort group selected from pre-treatment archival data and matched to a subsequent cohort currently receiving a treatment. Although prone to the same threats to study validity as any quasi-experiment, issues related to selection, history, and maturation can be particularly challenging. However, use of a historical cohort control group can reduce noncomparability of treatment and control conditions through local, focal matching. In addition, a historical cohort control group design can alleviate concerns about denying program access to students in order to form a control group, minimize resource requirements and disruption to school routines, and make use of archival data schools and school districts collect and find meaningful. Accessed 12,614 times on https://pareonline.net from June 23, 2014 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

The Color of Postfeminism: Representations of Black and White Women in Popular Music Videos

The sexualization and objectification of women in popular music videos has acted as a consistent obstacle for the feminist movement. Within a postfeminist framework -- postfeminism being a rejection of feminist ideas and a belief that the activist feminism of years past no longer serves a purpose -- music video viewers are able to see both positive advances and negative reversals. One problem often associated with the postfeminist movement is the lack of acknowledgment of race, as has historically been the case for the feminist movement, white, middle-class women are almost always the largest representation, with non-white women more often than not forgotten. The world of the popular music video is certainly no exception to this rule. Although postfeminism boasts many advances for women -- an increase in choice, a strong sense of independence and freedom, along with sexual liberties -- most of these advances are limited to white women. Despite these advances, postfeminist ideas are further limited by capitalism, consumerism, and white patriarchy, calling into question the legitimacy and efficacy of postfeminism