Primordial non-Gaussianity from LAMOST surveys

发布时间：2018-03-19 09:46

  本文选题：cosmology　切入点：large　出处：《Research in Astronomy and Astrophysics》2010年02期 　论文类型：期刊论文

【摘要】：The primordial non-Gaussianity (PNG) in the matter density perturbation is a very powerful probe of the physics of the very early Universe. The local PNG can induce a distinct scale-dependent bias on the large scale structure distribution of galaxies and quasars, which could be used for constraining it. We study the detection limits of PNG from the surveys of the LAMOST telescope. The cases of the main galaxy survey, the luminous red galaxy (LRG) survey, and the quasar survey of dif- ferent magnitude limits are considered. We find that the Main1 sample (i.e. the main galaxy survey which is one magnitude deeper than the SDSS main galaxy survey, or r 18.8) could only provide a very weak constraint on PNG. For the Main2 sample (r 19.8) and the LRG survey, the 2σ (95.5%) limits on the PNG parameter fNL are |fNL| 145 and |fNL| 114 respectively, which are comparable to the current limit from cosmic microwave background (CMB) data. The quasar survey could provide a much more stringent constraint, and we find that the 2σ limit for |fNL| is between 50 and 103, depending on the magnitude limit of the survey. With Planck-like priors on cosmological parameters, the quasar survey with g 21.65 would improve the constraint to |fNL| 43 (2σ). We also discuss the possibility of further tightening the constraint by using the relative bias method proposed by Seljak.
[Abstract]:The primordial non-Gaussianity (PNG) in the matter density perturbation is a very powerful probe of the physics of the very early Universe. The local PNG can induce a distinct scale-dependent bias on the large scale structure distribution of galaxies and quasars, which could be used for constraining it. We study the detection limits of PNG from the surveys of the LAMOST telescope. The cases of the main galaxy survey, the luminous red Galaxy (LRG) survey, and the quasar survey of dif- ferent magnitude limits are considered. We find that the Main1 sample (i.e. the main galaxy survey which is one magnitude deeper than the SDSS main galaxy survey or R could only provide a 18.8) very weak constraint on PNG. For the Main2 sample (r 19.8) and The LRG survey, the 2 (95.5%) limits on the PNG parameter fNL are |fNL| 145 and |fNL| 114 respectively, which are comparable to the current limit from cosmic microwave background (CMB) data. The quasar survey could provide a much more stringent constraint, and we find that the limit for |fNL| is 2 between 50 and 103, depending on the magnitude limit of the survey. With Planck-like priors on cosmological parameters, the quasar survey with G would improve the constraint 21.65 to fNL| 43 | (2 sigma). We also discuss the possibility of further tightening the constraint by using the relative bias method proposed by Seljak.

【基金】：supported by the National Natural Science Foundation of China under the Distinguished Young Scholar Grant 10525314 the Key Project Grant 10533010，by the ChineseAcademy of Sciences under grant KJCX3-SYW-N2 by the Ministry of Science and Technologynational basic science Program (Project 973) under grant No. 2007CB815401
【分类号】：P158
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本文编号：1633724