Gravastars or Black Holes as Consequence of the Einstein's Theory ...

Gravastar or Normal StarIn this case we can see that V (R) = 0 now can have one, twoor three real roots, depending on the mass of the shell. Form > m c we have, say, R i , where R i+1 > R i . If we chooseR 0 > R 3 (for m = m c we have R 2 = R 3 ), then the star will notbe allowed in this region because the potential is greater thanthe zero. However, if we choose R 1 < R 0 < R 2 , the collapsewill bounce back and forth between R = R 1 and R = R 2 . Sucha possibility is shown in the following figures. This is exactlythe so-called ”bounded excursion” model mentioned in VW,and studied in some details in two previous works of ours. Ofcourse, in a realistic situation, the star will emit bothgravitational waves and particles, and the potential shall beself-adjusted to produce a minimum at R = R static whereV (R = R static ) = 0 = V ′ (R = R static ) whereby a gravastar ora normal star is finally formed, although we have found, inthat previous works, that for the gravastar with De Sitter’sinterior, the potential tends to −∞ when R tends to ∞.