Stellar Explosion in the Weak Field Approximation of the Brans-Dicke Theory.- V.Hamity, D. Barraco

H HAMITY , D. BARRACO

CLASSICAL AND QUANTUM GRAVITY

IOP PUBLISHING LTD

Lugar: Londres; Año: 2005 vol. 22 p. 3841 - 3852

0264-9381

Abstract We treat a very crude model of an exploding star, in the weak field approximation of the Brans?Dicke theory, in a scenario that resembles some characteristic data of a type Ia supernova. The most noticeable feature, in the electromagnetic component, is the relationship between the absolute magnitude at maximum brightness of the star and the decline rate in one magnitude from that maximum. This characteristic has become one of the most accurate methods to measure luminosity distances to objects at cosmological distances (Phillips M M 1993 Astrophys. J. 413 L105; see www.all-science- fair-projects.com / science fair projects encyclopedia / Supernova, for a brief description of supernovae types). An interesting result is that the active mass associated with the scalar field is totally radiated to infinity, representing a mass loss in the ratio of the ?tensor? component to the scalar component of 1 to ( 2 ω +3 ) ( ω is the Brans?Dicke parameter), in agreement with a general result of Hawking (1972 Commun. Math. Phys. 25 167). Then, this model shows explicitly, in a dynamical case, the mechanism of the radiation of a scalar field, which is necessary to understand the Hawking result