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C Einstein-DeSitter metric spacetime !!!!
C It emulates the Robertson-Walker universe
C near t=0, with zero pressure, and k=0
C See :J.N. Islam, An Introduction to
C Mathematical Cosmology, Cambridge, 1992 and
C S. Hawking, G.F.R. Ellis, The Large Scale
C Structure of space-time, Cambridge, 1973
C
C Author : D. Vulcanov (Timisoara, Romania)
C see ../../README for copyright & licensing info
C
C $Header$
#include "cctk.h"
#include "cctk_Parameters.h"
subroutine Exact__de_Sitter(
$ x, y, z, t,
$ gdtt, gdtx, gdty, gdtz,
$ gdxx, gdyy, gdzz, gdxy, gdyz, gdzx,
$ gutt, gutx, guty, gutz,
$ guxx, guyy, guzz, guxy, guyz, guzx,
$ psi, Tmunu_flag)
implicit none
DECLARE_CCTK_PARAMETERS
c input arguments
CCTK_REAL x, y, z, t
c output arguments
CCTK_REAL gdtt, gdtx, gdty, gdtz,
$ gdxx, gdyy, gdzz, gdxy, gdyz, gdzx,
$ gutt, gutx, guty, gutz,
$ guxx, guyy, guzz, guxy, guyz, guzx
CCTK_REAL psi
LOGICAL Tmunu_flag
c local variables
CCTK_REAL arad
CCTK_REAL am
C This model has a cosmological constant
C ==> it sets the stress-energy tensor in the "CalcTmunu" code
Tmunu_flag = .true.
arad = de_Sitter__scale
am=arad*t**(4.0D0/3.0D0)
gdtt = -1.0D0
gdtx = 0.0D0
gdty = 0.0D0
gdtz = 0.0D0
gdxx = am
gdyy = am
gdzz = am
gdxy = 0.d0
gdyz = 0.d0
gdzx = 0.d0
gutt = -1.d0
gutx = 0.d0
guty = 0.d0
gutz = 0.d0
guxx = 1.d0/am
guyy = 1.d0/am
guzz = 1.d0/am
guxy = 0.d0
guyz = 0.d0
guzx = 0.d0
return
end
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