IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Splitting thin shells of counter rotating particles
and their thick Einstein-Vlasov counterparts
Autor/es:
REINALDO J. GLEISER; MARCOS A. RAMIREZ
Lugar:
México DF
Reunión:
Congreso; 19 International Conference on General Relativity and Gravitation; 2010
Institución organizadora:
Instituto de Ciencias Nucleares - Universidad Nacional Autónoma de México
Resumen:
<!--
@page { size: 21cm 29.7cm; margin: 2cm }
P { margin-bottom: 0.21cm }
-->
In this work we study the dynamics of self gravitating spherically
symmetric thin shells made of counter rotating particles. We consider
all possible velocity distributions for the particles, and show that
the equations of motion by themselves do not constrain this
distribution. We therefore consider the dynamical stability of the
resulting configurations under several possible processes. This
include the stability of static configurations as a whole, where we
find a lower bound for the compactness of the shell. We analyse also
the stability of the single particle orbits and find conditions for
"single particle evaporation". In the case of a shell with
particles whose angular momentum are restricted to two values, we
consider the conditions for stability under splitting into two
separate shells. This analysis leads to the conclusion that under
certain conditions, that are given explicitly, an evolving shell may
split into two or more separate shells. We provide explicit examples
to illustrate this phenomenon. We also include a derivation of the
thick to thin shell limit for an Einstein shell that shows that the
limiting distribution of angular momenta is unique, covering
continuously a finite range of values. Finally we deal with
Einstein-Vlasov systems which are static, spherically symmetric and
whose particles can only have a discrete set of values for their
angular momentum. We prove some general properties which hold for a
wide class of these shells and compare with previous results. We also
develop a concrete family of shells and for these we provide
arguments for the existence of a thin shell limit, showing that this
limit, if exists, is in accordance with the thin shells that we have
analysed before.