• DOI:10.1088/1475-7516/2016/02/018
• Corpus ID: 119246295

Precision measurement of the local bias of dark matter halos

@article{Lazeyras2015PrecisionMO,
  title={Precision measurement of the local bias of dark matter halos},
  author={Titouan Lazeyras and Christian Wagner and Tobias Baldauf and Fabian Schmidt},
  journal={Journal of Cosmology and Astroparticle Physics},
  year={2015},
  volume={2016},
  pages={018 - 018}
}

• Titouan Lazeyras, C. Wagner, +1 author F. Schmidt
• Published 3 November 2015
• Physics
• Journal of Cosmology and Astroparticle Physics

We present accurate measurements of the linear, quadratic, and cubic local bias of dark matter halos, using curved “separate universe” N-body simulations which effectively incorporate an infinite-wavelength overdensity. This can be seen as an exact implementation of the peak-background split argument. We compare the results with the linear and quadratic bias measured from the halo-matter power spectrum and bispectrum, and find good agreement. On the other hand, the standard peak-background split applied to the Sheth & Tormen (1999) and Tinker et al. (2008) halo mass functions matches the measured linear bias parameter only at the level of 10%. The prediction from the excursion set-peaks approach performs much better, which can be attributed to the stochastic moving barrier employed in the excursion set-peaks prediction. We also provide convenient fitting formulas for the nonlinear bias parameters b2(b1) and b3(b1), which work well over a range of redshifts.