If i would like to modify the code including the consistency relation, is
that ok i change the line 76 of power_tilt.f90 as
AP%rat = -6.2*ant (as per eq. (7.151) in Liddle & Lyth text book)
and change the line 73 of params.ini also accordingly.
Would you please let me know whether i should make any other changes in
the code?
Thanking you in anticipation!
CAMB - consistency relation
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Re: CAMB - consistency relation
You can just edit power_tilt.f90, yes. Of course you can also just give CAMB the correct amplitude and tilt in the .ini file.
However I thought the relation here was
r = -8 n_t
(CAMB defines things in terms of the scalar curvature perturbation in early radiation domination)
However I thought the relation here was
r = -8 n_t
(CAMB defines things in terms of the scalar curvature perturbation in early radiation domination)
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- Posts: 21
- Joined: September 28 2004
- Affiliation: University of Lisbon
CAMB - consistency relation
Hi there,
Antony is right that the coefficient should be 8. In the 1990s several different definitions of [tex]r[/tex] were in circulation, and the one our book used had [tex]r=12.4 \epsilon[/tex] where [tex]\epsilon[/tex] is the slow-roll parameter. Nowadays practically everyone, including CAMB, WMAP, etc, defines [tex]r=16\epsilon[/tex], which gives [tex]r=-8n_{{\rm T}}[/tex].
best,
Andrew
Antony is right that the coefficient should be 8. In the 1990s several different definitions of [tex]r[/tex] were in circulation, and the one our book used had [tex]r=12.4 \epsilon[/tex] where [tex]\epsilon[/tex] is the slow-roll parameter. Nowadays practically everyone, including CAMB, WMAP, etc, defines [tex]r=16\epsilon[/tex], which gives [tex]r=-8n_{{\rm T}}[/tex].
best,
Andrew