Effective field theory of cosmological perturbations

By F. Piazza, F. Vernizzi. 2013

133 citations recorded by the source corpus.

The effective field theory of cosmological perturbations stems from considering a cosmological background solution as a state displaying spontaneous breaking of time translations and (adiabatic) perturbations as the related Nambu–Goldstone modes. With this insight, one can systematically develop a theory for the cosmological perturbations during inflation and, with minor modifications, also describe in full generality the gravitational interactions of dark energy, which are relevant for late-time cosmology. The formalism displays a unique set of Lagrangian operators containing an increasing number of cosmological perturbations and derivatives. We give an introductory description of the unitary gauge formalism for theories with broken gauge symmetry—that allows us to write down the most general Lagrangian—and of the Stückelberg ‘trick’—that allows to recover gauge invariance and to make the scalar field explicit. We show how to apply this formalism to gravity and cosmology and we reproduce the detailed analysis of the action in the ADM variables. We also review some basic applications to inflation and dark energy.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/499845b2fddd450493a253cd5f292915f76c1075

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Citations in the corpus

Effective description of higher-order scalar-tensor theories (2017, unknown): “To find the associated quadratic action, we can proceed similarly to what was done in [4, 6].”
Exploring gravitational theories beyond Horndeski (2014, methodology): “[15, 16, 11, 17] (see [31, 33] for reviews).”
Effective field theory of dark energy: A review (2019, background): “It is possible to think of this scalar field as the Goldstone field which inevitably appears upon application of the Stückelberg trick as consequence of broken time translations characteristic of an expanding universe [36].”
A systematic approach to generalisations of General Relativity and their cosmological implications (2018, background): “Using the language of effective description of dark energy [233, 234, 235] in terms of lapse, shift and the extrinsic curvature, the quadratic action for DHOST can be written as [236]”
Cosmological tests of modified gravity (2015, background): “Another approach is to build the effective action [243, 244, 245, 246, 247, 248, 249, 250, 251] following the effective field theory approach developed for inflationary models [252, 253].”
A unifying description of dark energy (2014, methodology): “This approach was initially inspired by the so-called effective field theory (EFT) formalism, pioneered in [2, 3] for inflation and in [4] for minimally coupled dark energy, and later developed in the context of dark energy [5, 6, 7] (see also [8] for a recent review and e.”