Improved Forecasts for the Baryon Acoustic Oscillations and Cosmological Distance Scale

Hee-Jong Seo and Daniel J. Eisenstein
University of Arizona

We present the cosmological distance errors achievable using the baryonic acoustic oscillations as a standard ruler. We begin from a Fisher matrix formalism that is upgraded from Seo and Eisenstein (2003). We isolate the information from the baryonic peaks by excluding distance information from other less robust sources. Meanwhile, we accommodate the Lagrangian displacement distribution into the Fisher matrix calculation to reflect the gradual loss of information in scale and in time due to nonlinear growth, nonlinear bias, and nonlinear redshift distortions. We then show that we can contract the multi-dimensional fisher matrix calculations into a 2-dimensional or even 1-dimensional formalism with physically motivated approximations. We present the resulting fitting formula for the cosmological distance errors from galaxy redshift surveys as a function of survey parameters and nonlinearity, which saves us going through the 12-dimensional Fisher matrix calculations. Finally, we show excellent agreement between the error estimates from the revised Fisher matrix and the precision on the distance scale recovered from N-body simulations.

The paper itself (submitted to the Astrophysical Journal).

A code in C implementing the fitting formula is posted here. The comments in the code explain the use.

Back Back to Daniel Eisenstein's Home Page

Address questions and comments about this server to