Loop corrections in nonlinear cosmological perturbation theory 2. Two point statistics and selfsimilarity
Feb, 1996
48 pages
Published in:
- Astrophys.J. 473 (1996) 620
e-Print:
- astro-ph/9602070 [astro-ph]
DOI:
Report number:
- FERMILAB-PUB-96-023-A
View in:
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Abstract: (arXiv)
We calculate the lowest-order non-linear contributions to the power spectrum, two-point correlation function, and smoothed variance of the density field, for Gaussian initial conditions and scale-free initial power spectra, . These results extend and in some cases correct previous work in the literature on cosmological perturbation theory. Comparing with the scaling behavior observed in N-body simulations, we find that the validity of non-linear perturbation theory depends strongly on the spectral index . For , we find excellent agreement over scales where the variance \sigma~2(R) \la 10; however, for , perturbation theory predicts deviations from self-similar scaling (which increase with ) not seen in numerical simulations. This anomalous scaling suggests that the principal assumption underlying cosmological perturbation theory, that large-scale fields can be described perturbatively even when fluctuations are highly non-linear on small scales, breaks down beyond leading order for spectral indices . For , the power spectrum, variance, and correlation function in the scaling regime can be calculated using dimensional regularization.References(35)
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