School of Astronomy (SoA) - Weekly Seminar

By: Amir Aghamousa (University of Pune, India)  

IPM Larak Building, School of Astronomy 

Address: Larak Garden, opposite Araj, Artesh Highway,Tehran, Iran

Abstract

The angular power spectrum of CMB temperature fluctuations is a measurable physical quantity that depends sensitively on the physics of the early universe. In particular, the shape of the angular power spectrum relates directly to parameters in the underlying cosmological models. In the cosmological context, it is conventional to employ parametric models that attempt to capture the essential physics of the problem via the pre-specified functional form. Using a nonparametric function estimation methodology, we present a comparative analysis of the WMAP 1-, 3-, 5-, and 7-year data releases for the CMB angular power spectrum with respect to the following key questions. (a) How well is the power spectrum determined by the data alone? (b) How well is the LCDM model supported by a model-independent, data-driven analysis? (c) What are the realistic uncertainties on peak/dip locations and heights? In addition we estimate the Cosmological Parameters and their correlations by using these nonparametric results and standard numerical calculation of Angular Power Spectrum.

E-mail: astro(at)ipm.ir