graduate

New large-scale galaxy clustering results from the SDSS and WiggleZ surveys

TYPEAstrophysics Seminar
Speaker:Dr. Eyal Kazin
Affiliation:NYU --> Swinburne
Date:08.08.2011
Time:13:30
Location:Lidow 605
Abstract:

Galaxy clustering measurements play an essential role in constraining
cosmology.
Here I present new clustering results obtained from the
Sloan Digital Sky Survey (SDSS; z<0.5) and the Australian WiggleZ survey
(z<1).

Combining SDSS and WiggleZ data sets we detect a significant baryonic
acoustic feature,
a relic from early Universe plasma waves that left ripples in the
distribution of matter.
This 140 Mpc signature is a cosmic standard ruler with wich we test the
geometry of the Universe and constrain parameters of the standard LCDM
model.

I also present preliminary results of a test of gravity on large-scales
(50-110 Mpc),
when using anisotropies in galaxy clustering measurements of the SDSS
luminous red galaxy sample,
Doppler shift measurements are strongly contaminated by degeneracies between
the Hubble expansion and peculiar velocities
causing an apparent anisotropy in redshift maps.  Because these ``redshift
distortions"  are
sensitive to the galaxies' dynamical environment, they can ultimately
be used to test General Relativity and alternative models.