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! $Header$
#include "cctk.h"
#undef DEBUG
module ricci
implicit none
private
public calc_connections
public calc_connectionderivs
public calc_connectionderivs2
public calc_ricci
public calc_ricciderivs
contains
subroutine calc_connections (gu, dgg, gamma)
CCTK_REAL, intent(in) :: gu(3,3), dgg(3,3,3)
CCTK_REAL, intent(out) :: gamma(3,3,3)
integer :: i,j,k,l
! Gamma^i_jk = 1/2 g^il (g_lj,k + g_lk,j - g_jk,l)
do i=1,3
do j=1,3
do k=1,3
gamma(i,j,k) = 0
do l=1,3
gamma(i,j,k) = gamma(i,j,k) + 0.5d0 * gu(i,l) &
* (dgg(l,j,k) + dgg(l,k,j) - dgg(j,k,l))
end do
end do
end do
end do
end subroutine calc_connections
subroutine calc_connectionderivs (gu, dgg, dgu, ddgg, dgamma)
CCTK_REAL, intent(in) :: gu(3,3), dgg(3,3,3), dgu(3,3,3), ddgg(3,3,3,3)
CCTK_REAL, intent(out) :: dgamma(3,3,3,3)
integer :: i,j,k,l,m
! Gamma^i_jk,l = 1/2 g^im,l (g_mj,k + g_mk,j - g_jk,m)
! + 1/2 g^im (g_mj,kl + g_mk,jl - g_jk,ml)
do i=1,3
do j=1,3
do k=1,3
do l=1,3
dgamma(i,j,k,l) = 0
do m=1,3
dgamma(i,j,k,l) = dgamma(i,j,k,l) &
+ 0.5d0 * dgu(i,m,l) * (dgg(m,j,k) + dgg(m,k,j) - dgg(j,k,m)) &
+ 0.5d0 * gu(i,m) * (ddgg(m,j,k,l) + ddgg(m,k,j,l) - ddgg(j,k,m,l))
end do
end do
end do
end do
end do
end subroutine calc_connectionderivs
subroutine calc_connectionderivs2 (gu, dgg, dgu, ddgg, ddgu, dddgg, ddgamma)
CCTK_REAL, intent(in) :: gu(3,3), dgg(3,3,3), dgu(3,3,3), ddgg(3,3,3,3), ddgu(3,3,3,3), dddgg(3,3,3,3,3)
CCTK_REAL, intent(out) :: ddgamma(3,3,3,3,3)
integer :: i,j,k,l,m,n
! Gamma^i_jk,l = 1/2 g^im,l (g_mj,k + g_mk,j - g_jk,m)
! + 1/2 g^im (g_mj,kl + g_mk,jl - g_jk,ml)
do i=1,3
do j=1,3
do k=1,3
do l=1,3
do m=1,3
ddgamma(i,j,k,l,m) = 0
do n=1,3
ddgamma(i,j,k,l,m) = ddgamma(i,j,k,l,m) &
+ 0.5d0 * ddgu(i,n,l,m) * (dgg(n,j,k) + dgg(n,k,j) - dgg(j,k,n)) &
+ 0.5d0 * dgu(i,n,l) * (ddgg(n,j,k,m) + ddgg(n,k,j,m) - ddgg(j,k,n,m)) &
+ 0.5d0 * dgu(i,n,m) * (ddgg(n,j,k,l) + ddgg(n,k,j,l) - ddgg(j,k,n,l)) &
+ 0.5d0 * gu(i,n) * (dddgg(n,j,k,l,m) + dddgg(n,k,j,l,m) - dddgg(j,k,n,l,m))
end do
end do
end do
end do
end do
end do
end subroutine calc_connectionderivs2
subroutine calc_ricci (gamma, dgamma, ri)
CCTK_REAL, intent(in) :: gamma(3,3,3), dgamma(3,3,3,3)
CCTK_REAL, intent(out) :: ri(3,3)
#ifdef DEBUG
CCTK_REAL :: nrm, cnt
#endif
integer :: i,j,k,l
! R_ij = Gamma^k_ij,k - Gamma^k_ik,j
! + Gamma^k_lk Gamma^l_ij - Gamma^k_lj Gamma^l_ki
do i=1,3
do j=1,3
ri(i,j) = 0
do k=1,3
ri(i,j) = ri(i,j) + dgamma(k,i,j,k) - dgamma(k,i,k,j)
do l=1,3
ri(i,j) = ri(i,j) + gamma(k,l,k) * gamma(l,i,j) &
& - gamma(k,l,j) * gamma(l,k,i)
end do
end do
end do
end do
#ifdef DEBUG
! check symmetries
sum = 0
cnt = 0
do i=1,3
do j=1,3
sum = sum + (ri(i,j) - ri(j,i))**2
cnt = cnt + ri(i,j)**2
end do
end do
if (sum > 1.0e-12 * cnt) call CCTK_WARN (0, "Ricci tensor is not symmetric")
#endif
end subroutine calc_ricci
subroutine calc_ricciderivs (gamma, dgamma, ddgamma, dri)
CCTK_REAL, intent(in) :: gamma(3,3,3), dgamma(3,3,3,3), ddgamma(3,3,3,3,3)
CCTK_REAL, intent(out) :: dri(3,3,3)
#if 0
CCTK_REAL :: nrm, cnt
#endif
integer :: i,j,k,l,m
! R_ij = Gamma^k_ij,k - Gamma^k_ik,j
! + Gamma^k_lk Gamma^l_ij - Gamma^k_lj Gamma^l_ki
do i=1,3
do j=1,3
do k=1,3
dri(i,j,k) = 0
do l=1,3
dri(i,j,k) = dri(i,j,k) + ddgamma(l,i,j,l,k) &
& - ddgamma(l,i,l,j,k)
do m=1,3
dri(i,j,k) = dri(i,j,k) + dgamma(l,m,l,k) * gamma(m,i,j) &
& + gamma(l,m,l) * dgamma(m,i,j,k) &
& - dgamma(l,m,j,k) * gamma(m,l,i) &
& - gamma(l,m,j) * dgamma(m,l,i,k)
end do
end do
end do
end do
end do
#if 0
/* Does not work when dri=0 */
! check symmetries
nrm = 0
cnt = 0
do i=1,3
do j=1,3
do k=1,3
nrm = nrm + (dri(i,j,k) - dri(j,i,k))**2
cnt = cnt + dri(i,j,k)**2
end do
end do
end do
cnt = cnt + sum(gamma**2)
if (nrm > 1.0e-12 * cnt) then
print *,"nrm cnt ",nrm,cnt
print *,"ddgamma ",ddgamma
print *,"dri ",dri
end if
if (nrm > 1.0e-12 * cnt) call CCTK_WARN (0, "Ricci tensor derivative is not symmetric")
#endif
end subroutine calc_ricciderivs
end module ricci
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