2013/01/31 by Enrico Pajer, Matias Zaldarriaga, Matías Zaldarriaga · 4 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Classical mechanics #Cosmological perturbation theory #Cosmology and Gravitation Theories #Cutoff #Dissipative system #Effective field theory #Galaxies: Formation, Evolution, Phenomena #Inflation (cosmology) #Perturbation theory (quantum mechanics) #Physics #Quantum electrodynamics #Quantum field theory #Quantum mechanics #Renormalization #Renormalization group #Scale (ratio) #Statistical physics #Theoretical physics #Universe #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2013/08/037
24 pages, 2 figures, 1 mathematica notebook
arxiv created 2013/02/03 · openalex publication_date 2013/08/20 · arxiv updated 2015/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Standard perturbation theory (SPT) for large-scale matter inhomogeneities is unsatisfactory for at least three reasons: there is no clear expansion parameter since the density contrast is not small on all scales; it does not fully account for deviations at large scales from a perfect pressureless fluid induced by short-scale non-linearities; for generic initial conditions, loop corrections are UV-divergent, making predictions cutoff dependent and hence unphysical. The Effective Field Theory of Large Scale Structures successfully addresses all three issues. Here we focus on the third one and show explicitly that the terms induced by integrating out short scales, neglected in SPT, have exactly the right scale dependence to cancel all UV-divergences at one loop, and this should hold at all loops. A particularly clear example is an Einstein deSitter universe with no-scale initial conditions P in ∼ k n . After renormalizing the theory, we use self-similarity to derive a very simple result for the final power spectrum for any n , excluding two-loop corrections and higher. We show how the relative importance of different corrections depends on n . For n ∼ −1.5, relevant for our universe, pressure and dissipative corrections are more important than the two-loop corrections.