I have just simple question.

In subroutine initial, equations.f90 in CAMB,

what does y(EV%g_ix+1) mean?

I know y(EV%g_ix) is clxg, and this is density perturbation of photon.

But I don't know about y(EV%g_ix+1).

Just differential value about tau?

Any help would be appreciated.

Code: Select all

```
! Photons
y(EV%g_ix)=InitVec(i_clxg)
y(EV%g_ix+1)=InitVec(i_qg)
```