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Caltech

TAPIR Seminar

Friday, March 15, 2013
2:00pm to 3:00pm
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Cahill 370
Probing the Large Scale Anisotropies of the Universe from the CMB Temperature and Polarization Data
Grigor Aslanyan, Research Fellow, Physics, University of Auckland, New Zealand,

A six-parameter LCDM model is an excellent fit to the WMAP data, however several types of anomalies (deviations from LCDM) have been reported, especially on large scales (l<20). For example, possible deviations from the isotropy of the universe on large scales have been previously discussed in literature.  We do a detailed analysis of the seven and nine year WMAP temperature data for three different flat topologies and obtain bounds for their size using the Feldman-Cousins method. We present a formalism for using the polarization maps to improve these bounds and give forecasts for WMAP and Planck data. We also perform a Markov Chain Monte Carlo (MCMC) Bayesian analysis to constrain two other scenarios of isotropy breaking due to a semiclassical perturbation in the primordial universe.

For more information, please contact JoAnn Boyd by phone at 4280 or by email at [email protected].