Halo Zel’dovich model and perturbation theory: Dark matter power spectrum and correlation function
- University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Stanford University, CA (United States); Stanford University, CA (United States). Kavli Institute for Particle Astrophysics & Cosmology
Perturbation theory for dark matter clustering has received a lot of attention in recent years, but its convergence properties remain poorly justified and there is no successful model that works both for correlation functions and for power spectra. In this paper we present the halo Zel’dovich approach combined with perturbation theory, in which we use standard perturbation theory at one-loop order (SPT) at very low k, and connect it to a version of the halo model, for which we adopt the Zel’dovich approximation plus a Padé expansion of a compensated one-halo term. This low-k matching allows us to determine the one-halo term amplitude and redshift evolution, both of which are in an excellent agreement with simulations, and approximately agree with the expected value from the halo model. Our Padé expansion approach of the one-halo term added to the Zel’dovich approximation identifies a typical halo scale averaged over the halo mass function, the halo radius scale of order of 1 Mpc/h, and a much larger halo mass compensation scale, which can be determined from SPT. The model gives better than one-percent-accurate predictions for the correlation function above 5 Mpc/h at all redshifts, without any free parameters. With three fitted Padé expansion coefficients the agreement in the power spectrum is good to a percent up to k ~ 1h/Mpc, which can be improved to arbitrary k by adding higher-order terms in the Padé expansion.
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE; National Aeronautics and Space Administration (NASA)
- Grant/Contract Number:
- AC02-76SF00515; NNX12AG71G
- OSTI ID:
- 1261205
- Alternate ID(s):
- OSTI ID: 1184424
- Journal Information:
- Physical Review. D, Particles, Fields, Gravitation and Cosmology, Vol. 91, Issue 12; ISSN 1550-7998
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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