Neutron matter - Quark matter phase transition and Quark star

We consider the neutron matter quark matter phase transition along with possible existence of hybrid quark stars. The equation of state for neutron matter is obtained using a nonperturbative method with pion dressing of the neutron matter and an analysis similar to that of symmetric nuclear matter. The quark matter sector is treated perturbatively in the small distance domain. For bag constant $B^{1/4}$=148 MeV, a first order phase transition is seen. In the context of neutron quark hybrid stars, Tolman-Oppenheimer-Volkoff equations are solved using the equations of state for quark matter and for neutron matter with a phase transition as noted earlier. Stable solutions for such stars are obtained with the Chandrasekhar limit as 1.58 $M_\odot$ and radius around 10 km. The bulk of the star is quark matter with a thin crust of neutron matter of less than a kilometer.Comment: 28 pages including 9 figures, Revtex, IP/BBSR/92-8

Group Manifold Reduction of Dual N=1 d=10 Supergravity

We perform a group manifold reduction of the dual version of N=1 d=10 supergravity to four dimensions. The effects of the 3- and 4-form gauge fields in the resulting gauged N=4 d=4 supergravity are studied in particular. The example of the group manifold SU(2)xSU(2) is worked out in detail, and we compare for this case the four-dimensional scalar potential with gauged N=4 supergravity.Comment: 22 pages, revised section 3, typos corrected. Published versio

The properties of active galaxies at the extreme of eigenvector 1

Eigenvector 1 (EV1) is the formal parameter which allows the introduction of some order in the properties of the unobscured type 1 active galaxies. We aim to understand the nature of this parameter by analyzing the most extreme examples of quasars with the highest possible values of the corresponding eigenvalues $R_{Fe}$. We selected the appropriate sources from the Sloan Digital Sky Survey (SDSS) and performed detailed modeling, including various templates for the Fe II pseudo-continuum and the starlight contribution to the spectrum. Out of 27 sources with $R_{Fe}$ larger than 1.3 and with the measurement errors smaller than 20\% selected from the SDSS quasar catalog, only six sources were confirmed to have a high value of $R_{Fe}$, defined as being above 1.3. All other sources have $an R_{Fe}$ of approximately 1. Three of the high $R_{Fe}$ objects have a very narrow H$\beta$ line, below 2100 km s$^{-1}$ but three sources have broad lines, above 4500 km s$^{-1}$, that do not seem to form a uniform group, differing considerably in black hole mass and Eddington ratio; they simply have a very similar EW([OIII]5007) line. Therefore, the interpretation of the EV1 remains an open issue.Comment: Astronomy and Astrophysics (in press

Pentaquarks in the medium in the quark-meson coupling model

We calculate the properties of the pentaquarks $\Theta^+$ and $\Xi^{--,0}$ in symmetric nuclear matter using the quark meson coupling model (QMC). The stability of the $\Theta^+$ in the medium with respect to the channel $\Theta^+\to NK^+$ is discussed.Comment: 6 pages, 5 figures, revte

Gauging CSO groups in N=4 Supergravity

We investigate a class of CSO-gaugings of N=4 supergravity coupled to six vector multiplets. Using the CSO-gaugings we do not find a vacuum that is stable against all scalar perturbations at the point where the matter fields are turned off. However, at this point we do find a stable cosmological scaling solution.Comment: 21 page

A New Approach To Relativistic Gaussian Basis Functions: Theory And Applications

We present a new hybrid method to solve the relativistic Hartree-Fock-Roothan equations where the one- and two-electron radial integrals are evaluated numerically by defining the basis functions on a grid. This procedure reduces the computational costs in the evaluation of two-electron radial integrals. The orbitals generated by this method are employed to compute the ionization potentials, excitation energies and oscillator strengths of alkali-metal atoms and elements of group IIIA through second order many-body perturbation theor and other correlated theories.Comment: RevTex (15 pages) one figur

Grandparenting in Urban Bangalore, India: Support and Involvement From the Standpoint of Young Adult University Students

A variety of caregivers, including grandparents, help raise children. Among grandparents, most Western samples evidence a matrilateral (i.e., mother’s kin) bias in caregiving, and many studies show more positive impacts and stronger relationships with grandmothers than grandfathers. The aim of the present study is to test competing hypotheses about a potential laterality bias and explore contrasts between grandmothers and grandfathers in a sample of urban young adult university students in Bangalore, India. A sample of 377 (252 women) relatively mobile and high socioeconomic status individuals 17 to 25 years of age completed a survey consisting of sociodemographic and grandparenting questions. Results reveal generally little evidence of either a patrilateral or matrilateral bias, though findings varied for some outcomes. As illustrations, there were no differences in residential proximity or the most recent time when a participant saw matrilateral or patrilateral grandparents, whereas maternal grandmothers were more approving of one’s choice of a life partner than were paternal grandmothers. In inductively coded responses to an open-ended item about the roles of grandparents, maternal grandmothers were more often identified as “guides” and less often deemed “non-significant” than paternal grandmothers, while paternal grandfathers were less often viewed as guardians and more often noted for their influence compared with maternal grandparents. Findings also revealed differences between grandmothers and grandfathers, such as grandmothers playing more prominent roles in community and religious festivals. Findings are interpreted within changing residential, work, education, and family dynamics in urban India as well as a primary importance on parents relative to grandparents