20-22 May 2015
Asia/Bangkok timezone
The Centennial Celebration of General Relativity Theory and 80 Years of Thai Physics Graduate

CMB cold spot anomaly from cosmic void

21 May 2015, 10:15
15m
White Lotus ()

White Lotus

Oral presentation Astronomy, Astrophysics, and Cosmology Astronomy, Astrophysics and Cosmology (Sponsored by NARIT)

Speaker

Mr Anut Sangka (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

Description

One of the strongest evidence of the currently favoured standard ΛCDM (Lambda cold dark matter) model with the Big Bang origin came from the Cosmic Microwave Background (CMB) radiation measurement which show us the average temperature of the universe is 2.725 K with the Gaussian fluctuations of about 18 µK RMS. However there presents some anomalies that can be observed by CMB experiment. One of strange structures is the cold spot anomaly originally detected by NASA WMAP and now confirmed by the ESA Planck satellite mission. The temperature of the large cold spot is significant lower than average temperature. Moreover the size of the cold spot is notably larger than expectation, it radius is $5^{\circ}$ on sky. One of the best explanations of this cold spot is the integrated Sachs-Wolfe effect (ISW) cause by a single large cosmic void. Many research used Lemaître-Tolman-Bondi (LTB) metric embedded in ΛCDM background to construct cosmic void and determine ISW effect for explanation of the large cold spot but they ignored the small-scale effect from weak gravitational lensing. In this research we try to calculate ISW effect and weak lensing effect from LTB metric. In addition we used another cosmic void density profile from N-body simulation (Hamuas et,al 2014) to evaluate both ISW effect and weak lensing. And finally both results of LTB metric and cosmic void density profile will be compared to each other.

Primary author

Mr Anut Sangka (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

Co-authors

Dr Nuanwan Sanguansak (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand) Dr Utane Sawangwit (National Astronomical Research Institute of Thailand,Chiang Mai 50200, Thailand)

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