#### Bulg. J. Phys. vol.27 no.3 (2000), pp. 066-069

#### A Free Boundary Problem in the Theory of the Stars

S.S. Yazadjiev

go back^{1}, T.L. Boyadjiev^{2}, M.D. Todorov^{3}, P.P. Fiziev^{1}^{1}*Faculty of Physics, University of Sofia, Sofia, Bulgaria*^{2}*Faculty of Mathematics and Computer Science, University of Sofia, Sofia, Bulgaria*^{3}*5Instiitute of Applied Mathematics and Computer Science, Technical University of Sofia, Sofia, Bulgaria*Abstract.We investigate numerically models of the static spherically symmetric boson-fermion stars in the scalar-tensor theory of gravity with massive dilaton field. The proper mathematical model of such stars is interpreted as a nonlinear two-parametric eigenvalue problem with unknown internal boundary. To solve this problem the continuous analogue of newton method is used.