Speaker:
David Weinberg
Institution:
Ohio State Univ.
Speaker Link:
Date:
Thursday, October 18, 2012
Time:
3:30 pm
Location:
RH 101
ABSTRACT:
The remarkable discovery of cosmic acceleration poses two fundamental questions.
(1) Does acceleration reflect the presence of a new energy component or the breakdown of General Relativity on cosmological scales?
(2) If acceleration is caused by a new energy component, is it constant in space and time as expected for fundamental vacuum energy, or does it show evolution or variation that imply a dynamical field?
I will review observational methods for addressing these questions, with emphasis on baryon acoustic oscillations (BAO) and on galaxy clusters. I will show recent BAO results from the SDSS-III BOSS survey and recent cluster results based on cluster catalogs and stacked weak lensing mass measurements from SDSS-I and II.
The methods being pioneered in these investigations will grow steadily more powerful with future surveys such as the Dark Energy Survey, BigBOSS, LSST, Euclid, and WFIRST.
Host:
James Bullock