論文

基本情報

氏名 山内 大介
氏名(カナ) ヤマウチ ダイスケ
氏名(英語) Yamauchi Daisuke
所属 理学部 物理学科
職名 講師
researchmap研究者コード B000327615
researchmap機関 岡山理科大学

題名

CMB ISW-lensing bispectrum from cosmic strings

単著・共著の別

共著

著者

Daisuke Yamauchi, Yuuiti Sendouda, Keitaro Takahashi

概要

We study the effect of weak lensing by cosmic (super-)strings on the higher-order statistics of the cosmic microwave background (CMB). A cosmic string segment is expected to cause weak lensing as well as an integrated Sachs-Wolfe (ISW) effect, the so-called Gott-Kaiser-Stebbins (GKS) effect, to the CMB temperature fluctuation, which are thus naturally cross-correlated. We point out that, in the presence of such a correlation, yet another kind of the post-recombination CMB temperature bispectra, the ISW-lensing bispectra, will arise in the form of products of the auto- and cross-power spectra. We first present an analytic method to calculate the autocorrelation of the temperature fluctuations induced by the strings, and the cross-correlation between the temperature fluctuation and the lensing potential both due to the string network. In our formulation, the evolution of the string network is assumed to be characterized by the simple analytic model, the velocity-dependent one scale model, and the intercommutation probability is properly incorporated in order to characterize the possible superstringy nature. Furthermore, the obtained power spectra are dominated by the Poisson-distributed string segments, whose correlations are assumed to satisfy the simple relations. We then estimate the signal-to-noise ratios of the string-induced ISW-lensing bispectra and discuss the detectability of such CMB signals from the cosmic string network. It is found that in the case of the smaller string tension, Gμ << 10-7, the ISW-lensing bispectrum induced by a cosmic string network can constrain the string-model parameters even more tightly than the purely GKS-induced bispectrum in the ongoing and future CMB observations on small scales.

発表雑誌等の名称

Journal of Cosmology and Astroparticle Physics

出版者

02

041

開始ページ

終了ページ

発行又は発表の年月

2014/02

査読の有無

有り

招待の有無

無し

記述言語

英語

掲載種別

研究論文(学術雑誌)

ISSN

ID:DOI

10.1088/1475-7516/2014/02/041

ID:NAID(CiNiiのID)

ID:PMID

URL

JGlobalID

arXiv ID

1309.5528

ORCIDのPut Code

DBLP ID