Constraining Galaxy Bias and Cosmology Using Galaxy Clustering Data
Monday 15 December, 2:30 pm, Curia II
Zheng Zheng (Ohio State U.)
zhengz@astronomy.ohio-state.edu

Galaxy bias, which is the difference between galaxy and matter distributions, is usually regarded as an obstacle to constraining cosmological parameters using galaxy clustering data (e.g., from galaxy redshift surveys). On the other hand, galaxy bias contains information that tells us about the galaxy formation process, and an empirical determination of it can put useful constraints on galaxy formation models. The framework of the Halo Occupation Distribution (HOD) completely describes galaxy bias at the level of individual dark matter halos. In my talk, I first discuss inferring galaxy bias (HOD) from the SDSS galaxy clustering data with the
cosmological model assumed to be known. I show how to interpret departures from a power law in galaxy correlation function and the luminosity and color dependences of galaxy clustering by linking galaxies to dark matter halos. I also compare inferred HODs with predictions of galaxy formation models. I then move to a theoretical investigation of the possibility that we infer galaxy bias and constrain cosmological parameters simultaneously from observations of galaxy clustering.