I Radial BAO size method and Hubble parameter

[shadishacker]

Hi!

Can anyone tell me what the radial BAO size method is?
how do people use it to get to the H(z)?
I am reading the paper "Constraints on the Dark Side of the Universe and Observational Hubble Parameter Data " by Zhang et al. and I think I am lost!
Can anyone tell me very simple, how they do it?
-So they get the spectrum, find the redshift, and then look for adot/a ?
-How do they find adot?

 

[kimbyd]

It's described here, and unfortunately it isn't terribly simple:
https://arxiv.org/abs/0807.3551

The description is in section 4, page 14.

Basically, they take the "fiducial" expansion rate from a simple expansion model, and then correct it by comparing the observed correlation peak and compare it with the peak as measured from the CMB.