Accurate predictions on non--linear power spectra, at various redshift z, will be a basic tool to interpret cosmological data from next generation mass probes, so obtaining key information on Dark Energy nature. This calls for high precision simulations, covering the whole functional space of w(z) state equations and taking also into account the admitted ranges of other cosmological parameters; surely a difficult task. A procedure was however suggested, able to match the spectra at z=0, up to k~3, hMpc^{-1}, in cosmologies with an (almost) arbitrary w(z), by making recourse to the results of N-body simulations with w = const. In this paper we extend such procedure to high redshift and test our approach through a series of N-body gravitational simulations of various models, including a model closely fitting WMAP5 and complementary data. Our approach detects w= const. models, whose spectra meet the requirement within 1% at z=0 and perform even better at higher redshift, where they are close to a permil precision. Available Halofit expressions, extended to (constant) w \neq -1 are unfortunately unsuitable to fit the spectra of the physical models considered here. Their extension to cover the desired range should be however feasible, and this will enable us to match spectra from any DE state equation.

Casarini, L., Maccio', A., Bonometto, S. (2009). Dynamical dark energy simulations: High accuracy power spectra at high redshift. JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 03, 014 [10.1088/1475-7516/2009/03/014].

Dynamical dark energy simulations: High accuracy power spectra at high redshift

CASARINI, LUCIANO;
2009

Abstract

Accurate predictions on non--linear power spectra, at various redshift z, will be a basic tool to interpret cosmological data from next generation mass probes, so obtaining key information on Dark Energy nature. This calls for high precision simulations, covering the whole functional space of w(z) state equations and taking also into account the admitted ranges of other cosmological parameters; surely a difficult task. A procedure was however suggested, able to match the spectra at z=0, up to k~3, hMpc^{-1}, in cosmologies with an (almost) arbitrary w(z), by making recourse to the results of N-body simulations with w = const. In this paper we extend such procedure to high redshift and test our approach through a series of N-body gravitational simulations of various models, including a model closely fitting WMAP5 and complementary data. Our approach detects w= const. models, whose spectra meet the requirement within 1% at z=0 and perform even better at higher redshift, where they are close to a permil precision. Available Halofit expressions, extended to (constant) w \neq -1 are unfortunately unsuitable to fit the spectra of the physical models considered here. Their extension to cover the desired range should be however feasible, and this will enable us to match spectra from any DE state equation.
Articolo in rivista - Articolo scientifico
cosmological simulations, gravitational lensing, power spectrum
English
2009
03
014
none
Casarini, L., Maccio', A., Bonometto, S. (2009). Dynamical dark energy simulations: High accuracy power spectra at high redshift. JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 03, 014 [10.1088/1475-7516/2009/03/014].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/21893
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