Spherical collapse models with clustered dark energy

Chia Chun Chang, Wolung Lee, Kin Wang Ng

研究成果: 雜誌貢獻文章

2 引文 (Scopus)

摘要

We investigate the clustering effect of dark energy (DE) in the formation of galaxy clusters using the spherical collapse model. Assuming a fully clustered DE component, the spherical overdense region is treated as an isolated system which conserves the energy separately for both matter and DE inside the spherical region. Then, by introducing a parameter r to characterize the degree of DE clustering, which is defined by the nonlinear density contrast ratio of matter to DE at turnaround in the recollapsing process, i.e. r≡δde,ta NL∕δm,ta NL, we are able to uniquely determine the spherical collapsing process and hence obtain the virialized overdensity Δvir through a proper virialization scheme. Estimation of the virialized overdensities from current observation on galaxy clusters suggests that 0.5<r<0.8 at 1σ level for the clustered DE with w<−0.9. Also, we compare our method to the linear perturbation theory that deals with the growth of DE perturbation at early times. While both results are consistent with each other, our method is practically simple and it shows that the collapse process is rather independent of initial DE perturbation and its evolution at early times.

原文英語
頁(從 - 到)12-20
頁數9
期刊Physics of the Dark Universe
19
DOIs
出版狀態已發佈 - 2018 三月

指紋

dark energy
energy
perturbation
galaxies
perturbation theory

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

引用此文

Spherical collapse models with clustered dark energy. / Chang, Chia Chun; Lee, Wolung; Ng, Kin Wang.

於: Physics of the Dark Universe, 卷 19, 03.2018, p. 12-20.

研究成果: 雜誌貢獻文章

Chang, Chia Chun ; Lee, Wolung ; Ng, Kin Wang. / Spherical collapse models with clustered dark energy. 於: Physics of the Dark Universe. 2018 ; 卷 19. 頁 12-20.
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