Gravitation and Duality Symmetry

By generalizing the Hodge dual operator to the case of soldered bundles, and working in the context of the teleparallel equivalent of general relativity, an analysis of the duality symmetry in gravitation is performed. Although the basic conclusion is that, at least in the general case, gravitation is not dual symmetric, there is a particular theory in which this symmetry shows up. It is a self dual (or anti-self dual) teleparallel gravity in which, due to the fact that it does not contribute to the interaction of fermions with gravitation, the purely tensor part of torsion is assumed to vanish. The ensuing fermionic gravitational interaction is found to be chiral. Since duality is intimately related to renormalizability, this theory may eventually be more amenable to renormalization than teleparallel gravity or general relativity.Comment: 7 pages, no figures. Version 2: minor presentation changes, references added. Accepted for publication in Int. J. Mod. Phys.

Stress reduction in the hospital room: applying Ulrich's theory of supportive design

Hospital rooms may exacerbate or reduce patients' stress. According to Ulrich's (1991) theory of supportive design, the hospital environment will reduce stress if it fosters perceptions of control (PC), social support (SS), and positive distraction (PD). An experimental study was conducted to test this theory. Participants were asked to imagine a hospitalization scenario and were exposed to one of 8 lists of elements that the hospital room would provide selected to facilitate PC, SS, PD, or 1 of all the possible combinations of these elements. Results confirmed Ulrich's theory. Participants expected significantly less stress in the situations where all (or only PD and SS) elements were present. Meditational analyses confirmed that the number of elements in the hospital room affects expected stress through the perceptions of how much positive distraction and social support it is perceived to provide, but not through the perception of the level of perceived control available.info:eu-repo/semantics/publishedVersio

Analytical results for long time behavior in anomalous diffusion

We investigate through a Generalized Langevin formalism the phenomenon of anomalous diffusion for asymptotic times, and we generalized the concept of the diffusion exponent. A method is proposed to obtain the diffusion coefficient analytically through the introduction of a time scaling factor $\lambda$. We obtain as well an exact expression for $\lambda$ for all kinds of diffusion. Moreover, we show that $\lambda$ is a universal parameter determined by the diffusion exponent. The results are then compared with numerical calculations and very good agreement is observed. The method is general and may be applied to many types of stochastic problem