J. Martinez et D. Pavon, RADIATING GRAVITATIONAL COLLAPSE WITH BULK VISCOSITY, Monthly Notices of the Royal Astronomical Society, 268(3), 1994, pp. 654-664
The complete gravitational collapse of a spherically symmetric dense s
tar with an outgoing radial heat flow and a dissipative bulk pressure
is studied. The behaviour of the luminosity, temperature, sound speed
and adiabatic index is analysed. The neutrino trapping in the core of
the star in the last phases of the collapse makes the bulk pressure no
n-negligible as measured against the hydrostatic pressure. Our work ge
neralizes that of some previous authors.