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Title: Neutrinos in non-linear structure formation — a simple SPH approach

We present a novel method for implementing massive neutrinos in N-body simulations. Instead of sampling the neutrino velocity distribution by individual point particles we take neutrino free-streaming into account by treating it as an effective redshift dependent sound speed in a perfect isothermal fluid, and assume a relation between the sound speed and velocity dispersion of the neutrinos. Although the method fails to accurately model the true neutrino power spectrum, it is able to calculate the total matter power spectrum to the same accuracy as more complex hybrid neutrino methods, except on very small scales. We also present an easy way to update the publicly available GADGET-2 version with this neutrino approximation.
Authors:
;  [1] ;  [2]
  1. Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C (Denmark)
  2. Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen (Denmark)
Publication Date:
OSTI Identifier:
22280075
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2012; Journal Issue: 02; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; APPROXIMATIONS; ASTROPHYSICS; COMPUTERIZED SIMULATION; COSMOLOGY; ENERGY SPECTRA; NEUTRINOS; NONLINEAR PROBLEMS; RED SHIFT; SOUND WAVES; VELOCITY