Generalized Gross--Perry--Sorkin--Like Solitons

In this paper, we present a new solution for the effective theory of Maxwell--Einstein--Dilaton, Low energy string and Kaluza--Klein theories, which contains among other solutions the well known Kaluza--Klein monopole solution of Gross--Perry--Sorkin as special case. We show also the magnetic and electric dipole solutions contained in the general one.Comment: 10 latex pages, no figures. To appear in Class. Quant. Gravity

On the Space Time of a Galaxy

We present an exact solution of the averaged Einstein's field equations in the presence of two real scalar fields and a component of dust with spherical symmetry. We suggest that the space-time found provides the characteristics required by a galactic model that could explain the supermassive central object and the dark matter halo at once, since one of the fields constitutes a central oscillaton surrounded by the dust and the other scalar field distributes far from the coordinate center and can be interpreted as a halo. We show the behavior of the rotation curves all along the background. Thus, the solution could be a first approximation of a ``long exposition photograph'' of a galaxy.Comment: 8 pages REVTeX, 11 eps figure

Entangled coherent states and squeezing in N trapped ions

We consider a resonant bichromatic excitation of N trapped ions that generates displacement and squeezing in their collective motion conditioned to their ionic internal state, producing eventually Scrhodinger cat states and entangled squeezing. Furthermore, we study the case of tetrachromatic illumination or producing the so called entangled coherent states in two motional normal modes.Comment: 4 Revtex pages, no figures. To appear in Proceedings of "Mysteries, Puzzles and Paradoxes in Quantum Mechanics", Garda Lake, Italy (2001

Oscillatons revisited

In this paper, we study some interesting properties of a spherically symmetric oscillating soliton star made of a real time-dependent scalar field which is called an oscillaton. The known final configuration of an oscillaton consists of a stationary stage in which the scalar field and the metric coefficients oscillate in time if the scalar potential is quadratic. The differential equations that arise in the simplest approximation, that of coherent scalar oscillations, are presented for a quadratic scalar potential. This allows us to take a closer look at the interesting properties of these oscillating objects. The leading terms of the solutions considering a quartic and a cosh scalar potentials are worked in the so called stationary limit procedure. This procedure reveals the form in which oscillatons and boson stars may be related and useful information about oscillatons is obtained from the known results of boson stars. Oscillatons could compete with boson stars as interesting astrophysical objects, since they would be predicted by scalar field dark matter models.Comment: 10 pages REVTeX, 10 eps figures. Updated files to match version published in Classical and Quantum Gravit

A PHENOMENOLOGICAL STUDY: THE PERCEPTIONS OF HISPANIC MALES’ CLASSROOM BEHAVIOR BASED ON PATERNAL ABSENCE

This qualitative research study used a phenomenological perspective to describe the perceptions of classroom behavioral challenges experienced by Hispanic young adult males who grew up without a constant paternal figure. The purpose of the study was to discover the essence of the effects of father absence on Hispanic males’ educational experiences to inform both parents and educators of the internalized and externalized classroom behaviors. The study presented Feuerstein’s mediated learning experience (MLE) as a theory for limiting negative behaviors in Hispanic males caused by father absence both in and outside the classroom. The method of inquiry followed Creswell’s defining features of phenomenology which included: a description of the phenomenon; the identification of the young adult Hispanic male participants; a philosophical discussion of the phenomenology; the role of the researcher in the study of bracketing while remaining Dasein; data collection through demographic information, face-to-face interviews with study participants, and the inclusion of song lyrics relevant to the phenomenon; data analysis which developed into five themes; and a discussion of the essence of the father absence phenomenon. Hispanic young adult males in the study were found to experience multiple hardships both in school and in their lifeworld as the effect of father absence. Essential themes of father absence experience were relationship with mom, relationship with father, always stayed in school, friends are family, and self-concept. The study highlighted the essence of the father absence phenomenon and strengthened the phenomenological research process