The effective field theory of cosmological large scale structures

John Joseph M. Carrasco*, Mark P. Hertzberg, Leonardo Senatore

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

299 Scopus citations


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 N-body simulations. We find that the speed of sound of the effective fluid is c2s ≈ 10-6c2 and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)4. The predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≈ 0.24h Mpc-1.

Original languageEnglish (US)
Article number82
JournalJournal of High Energy Physics
Issue number9
StatePublished - Sep 2012


  • Cosmology of theories beyond the SM
  • Renormalization regularization and renormalons
  • Stochastic processes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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