論文

2018年11月23日

Dark Quest. I. Fast and Accurate Emulation of Halo Clustering Statistics and Its Application to Galaxy Clustering

  • Takahiro Nishimichi
  • ,
  • Masahiro Takada
  • ,
  • Ryuichi Takahashi
  • ,
  • Ken Osato
  • ,
  • Masato Shirasaki
  • ,
  • Taira Oogi
  • ,
  • Hironao Miyatake
  • ,
  • Masamune Oguri
  • ,
  • Ryoma Murata
  • ,
  • Yosuke Kobayashi
  • ,
  • Naoki Yoshida

記述言語
掲載種別
研究論文(学術雑誌)

We perform an ensemble of cosmological $N$-body simulations with $2048^3$<br />
particles for 101 cosmological models within a flat $w$CDM cosmology framework<br />
sampled based on a maximin-distance Sliced Latin Hypercube Design. By using the<br />
outputs of $N$-body simulations and the halo catalogs extracted in the range of<br />
$z=[0,1.48]$, we develop an emulator, Dark Emulator, which enables fast and<br />
accurate computations of halo clustering quantities, the halo mass function,<br />
halo-matter cross-correlation, and halo auto-correlation as a function of halo<br />
masses, redshift, separations and cosmological models, based on the Principal<br />
Component Analysis and the Gaussian Process Regression for the<br />
large-dimensional input and output data vector. We use a validation set of<br />
$N$-body simulations for cosmological models, which are not used in training<br />
the emulator, to assess the performance of the emulator. We show that, for<br />
typical halos hosting CMASS galaxies in the Sloan Digital Sky Survey, the<br />
emulator predicts the halo-matter cross correlation, relevant for galaxy-galaxy<br />
weak lensing, with an accuracy better than $2\%$ and the halo auto-correlation,<br />
relevant for galaxy clustering correlation, with an accuracy better than $4\%$.<br />
We give several demonstrations of the emulator. For instance, the emulator<br />
outputs can be used to study properties of halo mass density profiles such as<br />
the mass-concentration relation and splashback radius and their cosmology and<br />
redshift dependences. We also show that the emulator outputs can be combined<br />
with an analytical prescription of halo-galaxy connection such as the halo<br />
occupation distribution at the equation level, instead of using the mock<br />
catalogs, to make accurate predictions of galaxy clustering statistics such as<br />
the galaxy-galaxy weak lensing and the projected correlation function for any<br />
model within the $w$CDM cosmologies, with a CPU time of a few seconds.

リンク情報
arXiv
http://arxiv.org/abs/arXiv:1811.09504
URL
http://arxiv.org/abs/1811.09504v1

エクスポート
BibTeX RIS