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The other 99 percent.

Afshordi, Niyayesh.

The other 99 percent.

Record Type:	Electronic resources : Monograph/item
Title/Author:	The other 99 percent.
Author:	Afshordi, Niyayesh.
Description:	148 p.
Notes:	Adviser: David N. Spergel.
Notes:	Source: Dissertation Abstracts International, Volume: 65-06, Section: B, page: 2967.
Contained By:	Dissertation Abstracts International65-06B.
Subject:	Physics, Astronomy and Astrophysics.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3136690
ISBN:	0496838865

The other 99 percent.
Afshordi, Niyayesh.

The other 99 percent. - 148 p.

Adviser: David N. Spergel.

Thesis (Ph.D.)--Princeton University, 2004.

The Wilkinson Microwave Anisotropy Probe (WMAP) has recently provided us with an all-sky map of Cosmic Microwave Background (CMB) with a resolution of &sim;0.5°. The rest of the thesis is devoted to techniques that can be used to extract signatures of dark energy and hot gas from WMAP CMB maps. We first cross-correlate the WMAP maps with the distribution of galaxies in the Two Micron All Sky Survey (2MASS), and demonstrate the presence of Integrated Sachs-Wolfe (ISW) and thermal Sunyaev-Zel'dovich (SZ) effects at large and small angles respectively. In a flat universe, the ISW effect is interpreted as a signature of late time acceleration of the universe, caused by dark energy, while the thermal SZ effect traces the distribution of hot gas in clusters of galaxies. We go on to consider different aspects of observing dark energy via cross-correlating the CMB sky with galaxy surveys, and describe the potential of the method for constraining cosmological parameters. Finally, we devise an optimized filter match method to study the thermal SZ signature of 100 low-redshift X-ray clusters. Applying this method to the WMAP maps, we can put novel constraints on the gas fraction and concentration parameter of the Intra-Cluster Medium (ICM) in these clusters.

ISBN: 0496838865Subjects--Topical Terms:

227131
Physics, Astronomy and Astrophysics.

The other 99 percent.
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100 0 $a Afshordi, Niyayesh. $3 227905
245 1 4 $a The other 99 percent.
300 $a 148 p.
500 $a Adviser: David N. Spergel.
500 $a Source: Dissertation Abstracts International, Volume: 65-06, Section: B, page: 2967.
502 $a Thesis (Ph.D.)--Princeton University, 2004.
520 # $a The Wilkinson Microwave Anisotropy Probe (WMAP) has recently provided us with an all-sky map of Cosmic Microwave Background (CMB) with a resolution of &sim;0.5°. The rest of the thesis is devoted to techniques that can be used to extract signatures of dark energy and hot gas from WMAP CMB maps. We first cross-correlate the WMAP maps with the distribution of galaxies in the Two Micron All Sky Survey (2MASS), and demonstrate the presence of Integrated Sachs-Wolfe (ISW) and thermal Sunyaev-Zel'dovich (SZ) effects at large and small angles respectively. In a flat universe, the ISW effect is interpreted as a signature of late time acceleration of the universe, caused by dark energy, while the thermal SZ effect traces the distribution of hot gas in clusters of galaxies. We go on to consider different aspects of observing dark energy via cross-correlating the CMB sky with galaxy surveys, and describe the potential of the method for constraining cosmological parameters. Finally, we devise an optimized filter match method to study the thermal SZ signature of 100 low-redshift X-ray clusters. Applying this method to the WMAP maps, we can put novel constraints on the gas fraction and concentration parameter of the Intra-Cluster Medium (ICM) in these clusters.
520 # $a There is now overwhelming evidence that only less than one percent of the mass in the universe can be observed via its optical signature. This thesis examines some of the signatures of (optically) invisible components of our universe, which comprise more than 99 percent of its energy content, namely dark energy (&sim;70%), dark matter (&sim;25%), and hot gas (&sim;4%).
520 # $a We start by introducing an alternative model for Cold Dark Matter (CDM), which consists of massive Primordial Black Holes (PBH's). We study the imprint of Poisson fluctuations, due to the discrete nature of PBH's, on the cosmological power spectrum. Combining our results with Ly-alpha forest observations, we arrive at a new upper limit on the mass of PBH's. We then point out that evaporation of haloes with a small of number of PBH's puts a lower cut-off on the mass of CDM haloes.
590 $a School code: 0181.
650 # 0 $a Physics, Astronomy and Astrophysics. $3 227131
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710 0 # $a Princeton University. $3 212488
773 0 # $g 65-06B. $t Dissertation Abstracts International
790 $a 0181
790 1 0 $a Spergel, David N., $e advisor
791 $a Ph.D.
792 $a 2004
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