Initial Stellar Model

The stars obey a polytropic equation of state: P=χρ₀^1+1/n, with χ=constant. We choose n=1 to mimick stiff nuclear matter. In addition, the rotation law is given by

where Ω is the angular velocity of the fluid, Ω_c is Ω on the rotation axis, and R_eq is the equatorial coordinate radius. A is a dimensionless parameter that measures the degree of differential rotation, chosen to be unity in the simulations. This rotation law has been found to be a good approximation to the angular velocity profile of proto-neutron stars formed from core collapse. In the Newtonian limit, it reduces to

(r is the cylindrical radius.)

last updated 22 july 05 by dvd