Boson Stars with Large Self-interaction in (2+1) dimensions: an Exact Solution

An exact solution for a nonrotating boson star in (2+1) dimensional gravity with a negative cosmological constant is found. The relations among mass, particle number, and radius of the (2+1) dimensional boson star are shown.Comment: 16 pages, 7 figures, needs REVTeX (2nd revised version

Deconstructing Scalar QED at Zero and Finite Temperature

We calculate the effective potential for the WLPNGB in a world with a circular latticized extra dimension. The mass of the WLPNGB is calculated from the one-loop quantum effect of scalar fields at zero and finite temperature. We show that a series expansion by the modified Bessel functions is useful to calculate the one-loop effective potentials.Comment: 12 pages, 2 figures. RevTeX