The IRresummed Effective Field Theory of Large Scale Structures
Abstract
We present a new method to resum the effect of large scale motions in the Effective Field Theory of Large Scale Structures. Because the linear power spectrum in ΛCDM is not scale free the effects of the large scale flows are enhanced. Although previous EFT calculations of the equaltime density power spectrum at one and two loops showed a remarkable agreement with numerical results, they also showed a 2% residual which appeared related to the BAO oscillations. We show that this was indeed the case, explain the physical origin and show how a Lagrangian based calculation removes this differences. We propose a simple method to upgrade existing Eulerian calculations to effectively make them Lagrangian and compare the new results with existing fits to numerical simulations. Our new twoloop results agrees with numerical results up to k∼ 0.6 h Mpc{sup −1} to within 1% with no oscillatory residuals. We also compute power spectra involving momentum which is significantly more affected by the large scale flows. We show how keeping track of these velocities significantly enhances the UV reach of the momentum power spectrum in addition to removing the BAO related residuals. We compute predictions for the real space correlation function around the BAO scalemore »
 Authors:
 Stanford Institute for Theoretical Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305, U.S.A (United States)
 School of Natural Sciences, Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540 (United States)
 Publication Date:
 OSTI Identifier:
 22381995
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 02; Other Information: Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRELATION FUNCTIONS; FIELD THEORIES; FORECASTING; LAGRANGIAN FUNCTION; ORIGIN; POWER DENSITY; SENSITIVITY; SPACE; SPECTRA; VELOCITY
Citation Formats
Senatore, Leonardo, and Zaldarriaga, Matias, Email: senatore@stanford.edu, Email: matiasz@ias.edu. The IRresummed Effective Field Theory of Large Scale Structures. United States: N. p., 2015.
Web. doi:10.1088/14757516/2015/02/013.
Senatore, Leonardo, & Zaldarriaga, Matias, Email: senatore@stanford.edu, Email: matiasz@ias.edu. The IRresummed Effective Field Theory of Large Scale Structures. United States. doi:10.1088/14757516/2015/02/013.
Senatore, Leonardo, and Zaldarriaga, Matias, Email: senatore@stanford.edu, Email: matiasz@ias.edu. 2015.
"The IRresummed Effective Field Theory of Large Scale Structures". United States.
doi:10.1088/14757516/2015/02/013.
@article{osti_22381995,
title = {The IRresummed Effective Field Theory of Large Scale Structures},
author = {Senatore, Leonardo and Zaldarriaga, Matias, Email: senatore@stanford.edu, Email: matiasz@ias.edu},
abstractNote = {We present a new method to resum the effect of large scale motions in the Effective Field Theory of Large Scale Structures. Because the linear power spectrum in ΛCDM is not scale free the effects of the large scale flows are enhanced. Although previous EFT calculations of the equaltime density power spectrum at one and two loops showed a remarkable agreement with numerical results, they also showed a 2% residual which appeared related to the BAO oscillations. We show that this was indeed the case, explain the physical origin and show how a Lagrangian based calculation removes this differences. We propose a simple method to upgrade existing Eulerian calculations to effectively make them Lagrangian and compare the new results with existing fits to numerical simulations. Our new twoloop results agrees with numerical results up to k∼ 0.6 h Mpc{sup −1} to within 1% with no oscillatory residuals. We also compute power spectra involving momentum which is significantly more affected by the large scale flows. We show how keeping track of these velocities significantly enhances the UV reach of the momentum power spectrum in addition to removing the BAO related residuals. We compute predictions for the real space correlation function around the BAO scale and investigate its sensitivity to the EFT parameters and the details of the resummation technique.},
doi = {10.1088/14757516/2015/02/013},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 02,
volume = 2015,
place = {United States},
year = 2015,
month = 2
}

Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from Nbody simulations. We find that the speed of sound of the effective fluidmore »

On the renormalization of the effective field theory of large scale structures
Standard perturbation theory (SPT) for largescale 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 shortscale nonlinearities; for generic initial conditions, loop corrections are UVdivergent, 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,more » 
On the velocity in the Effective Field Theory of Large Scale Structures
We compute the renormalized twopoint functions of density, divergence and vorticity of the velocity in the Effective Field Theory of Large Scale Structures. Because of momentum and mass conservation, the corrections from short scales to the largescale power spectra of density, divergence and vorticity must start at order k{sup 4}. For the vorticity this constitutes one of the two leading terms. Exact (approximated) selfsimilarity of an Einsteinde Sitter (ΛCDM) background fixes the time dependence so that the vorticity power spectrum at leading order is determined by the symmetries of the problem and the power spectrum around the nonlinear scale. Wemore » 
The Effective Field Theory of Large Scale Structures at two loops
Large scale structure surveys promise to be the next leading probe of cosmological information. It is therefore crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbation theory for the weakly nonlinear regime of dark matter, where correlation functions are computed in an expansion of the wavenumber k of a mode over the wavenumber associated with the nonlinear scale k{sub NL}. Since most of the information is contained at high wavenumbers, it is necessary to compute higher order corrections to correlation functions. After the oneloop correction to the matter powermore »