1 code implementation • 11 Jul 2017 • Christopher M. Hirata
A key advantage of the BAO as a standard ruler is that it is a sharp feature and hence is more robust against broadband systematic effects than other cosmological probes.
Cosmology and Nongalactic Astrophysics
2 code implementations • 20 Sep 2016 • Xiao Fang, Jonathan A. Blazek, Joseph E. McEwen, Christopher M. Hirata
Cosmological perturbation theory is a powerful tool to predict the statistics of large-scale structure in the weakly non-linear regime, but even at 1-loop order it results in computationally expensive mode-coupling integrals.
Cosmology and Nongalactic Astrophysics
2 code implementations • 15 Mar 2016 • Joseph E. McEwen, Xiao Fang, Christopher M. Hirata, Jonathan A. Blazek
We present a novel algorithm, FAST-PT, for performing convolution or mode-coupling integrals that appear in nonlinear cosmological perturbation theory.
Cosmology and Nongalactic Astrophysics
no code implementations • 5 Jul 2005 • Christopher M. Hirata
(3) The spin-flip scatterings change the frequency of the photon and cause the photon spectrum to relax not to the kinetic temperature of the gas but to a temperature between the kinetic and spin temperatures, effectively reducing the strength of the Wouthuysen-Field coupling.
astro-ph
no code implementations • 10 Jun 2004 • Christopher M. Hirata, Uros Seljak
The first model predicts a gravitational-intrinsic (GI) correlation that can be much greater than the intrinsic-intrinsic (II) correlation for broad redshift distributions, and that remains when galaxies pairs at similar redshifts are rejected.
astro-ph
