I'm studying from the Dodelson book on Cosmology and I got stuck on a specific derivation. In this derivation I need to compute $$\frac{d}{dy}\left(\frac{1}{ayH}\right).$$ Here $y= \frac{a}{a_\text{eq}}$, a parameter. The book says that $$\frac{d}{dy}\left(\frac{1}{ayH}\right) = -(1+y)^{-1}(2ayH)^{-1},$$ but to me this doesn't make sense at all. I've tried writing everything out, but I never seem to get this result.
$\begingroup$
$\endgroup$
Add a comment
|