Numerical Investigation of Boson - Fermion Stars in Dilatonic Gravity
by
Todor Boyadjiev
Faculty of Mathematics and Informatics, University of Sofia "St. Kliment Ohridski"
Coauthors: Michail Todorov (Institute of Applied Mathematics and Computer Science,Technical University of Sofia), Plamen Fiziev (Faculty of Physics, University of Sofia "St. Kliment Ohridski"), Stoicho Yazadjiev (Faculty of Physics, University of Sofia "St. Kliment Ohridski")

A model of the static spherically symmetric boson-fermion stars in scalar-tensor theory of gravity with massive dilaton field is investigated numerically. The proper mathematical model of such stars is interpreted as a nonlinear two-parametric eigenvalue problem with unknown internal boundary. The Continuous Analogue of Newton Method which leads to two separate linear boundary value problems with different dimensions inside and outside the star, respectively, is used. The corresponding solutions in these regions are obtained independently by means of a spline-collocation scheme of forth order and after that they are matched. A nonlinear algebraic system for the spectral parameters - radius of the star and frequency of the bosonic field - is solved also.

In this way we obtain the behaviour of the basic geometric quantities and functions describing dilaton field and matter fields which build the star.

http://www.fmi.uni-sofia.bg/fmi/mech_anl/todor/index.htm

Date received: March 25, 2000

Copyright © 2000 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caen-52.