On the range of validity of perturbative models for galaxy clustering and its uncertainty
arXiv (Cornell University)(2023)
摘要
We explore the reach of analytical models at one-loop in Perturbation Theory
(PT) to accurately describe measurements of the galaxy power spectrum from
numerical simulations in redshift space. We consider the validity range in
terms of three different diagnostics: 1) the goodness of fit; 2) a
figure-of-bias quantifying the error in recovering the fiducial value of a
cosmological parameter; 3) an internal consistency check of the theoretical
model quantifying the running of the model parameters with the scale cut. We
consider different sets of measurements corresponding to an increasing
cumulative simulation volume in redshift space. For each volume we define a
median value and the associated scatter for the largest wavenumber where the
model is valid (the k-reach of the model). We find, as a rather general
result, that the median value of the reach decreases with the simulation
volume, as expected since the smaller statistical errors provide a more
stringent test for the model. This is true for all the three definitions
considered, with the one given in terms of the figure-of-bias providing the
most stringent scale cut. More interestingly, we find as well that the error
associated with the k-reach value is quite large, with a significant
probability of being as low as 0.1h Mpc^-1 (or, more generally,
up to 40
We explore as well the additional information on the growth rate parameter
encoded in the power spectrum hexadecapole, compared to the analysis of
monopole and quadrupole, as a function of simulation volume. While our analysis
is, in many ways, rather simplified, we find that the gain in the determination
of the growth rate is quite small in absolute value and well within the
statistical error on the corresponding figure of merit.
更多查看译文
关键词
perturbative models,galaxy,uncertainty
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要