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Advisor(s)
Abstract(s)
We consider a spherically symmetric gravitational collapse of a tachyon field
with an inverse square potential, which is coupled with a barotropic fluid. By
employing an holonomy correction imported from loop quantum cosmology, we
analyse the dynamics of the collapse within a semiclassical description. Using
a dynamical system approach, we find that the stable fixed points given by the
standard general relativistic setting turn into saddle points in the present
context. This provides a new dynamics in contrast to the black hole and naked
singularities solutions appearing in the classical model. Our results suggest
that classical singularities can be avoided by quantum gravity effects and are
replaced by a bounce. By a thorough numerical studies we show that, depending
on the barotropic parameter $\gamma$, there exists a class of solutions
corresponding to either a fluid or a tachyon dominated regimes. Furthermore,
for the case $\gamma \sim 1$, we find an interesting tracking behaviour between
the tachyon and the fluid leading to a dust-like collapse. In addition, we show
that, there exists a threshold scale which determines when an outward energy
flux emerges, as a non-singular black hole is forming, at the corresponding
collapse final stages.
Description
Keywords
Loop quantum cosmology Gravitational collapse
Citation
Publisher
World Scientific Publishing