frw(1) --- Imcat Users Guide --- section: imcattools_cosmology --- last changed: Thu Jul 10 HST
frw - compute physical quantities in FRW cosmologySYNOPSIS
frw [options....]where options are:
"-m Omega_matter " present Omega in matter (0.99)
"-l Omega_lambda " present Omega in lambda (0.0)
"-Z Z0 " starting redshift (1.e5)
"-s Zs " max source redshift (9.0)
"-d dlna " logarithmic step size (0.01)
"-u " print this messageDESCRIPTION
'frw' numerically integrates Freidmann equation to obtain physical quantities: z = redshift y = a / a0 = 1 / (1 + z) h = H / H0 = sqrt(Omegam / y^3 + Omegal + (1 - Omega0) / y^2) eta = conformal time zeta = eta0 - eta = conformal lookback time d = solution of ddotdot + 2 h ddot - (3/2) Omegam d / y^3 = 0 dphi = d / y = potential growth factor; r = radial comoving distance D = comoving angular diameter distance a = scale factor where Omega0 = Omega_matter + Omega_lambda and We start integrating at very high Z0 in order to get into pure growing mode, but only output for Z < Zs.
AUTHOR
Nick Kaiser --- kaiser@hawaii.edu