On graviton non-gaussianities during inflation

By J. Maldacena, G. L. Pimentel. 2011

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We consider the most general three point function for gravitational waves produced during a period of exactly de Sitter expansion. The de Sitter isometries constrain the possible shapes to only three: two preserving parity and one violating parity. These isometries imply that these correlation functions should be conformal invariant. One of the shapes is produced by the ordinary gravity action. The other shape is produced by a higher derivative correction and could be as large as the gravity contribution. The parity violating shape does not contribute to the bispectrum [1, 2], even though it is present in the wavefunction. We also introduce a spinor helicity formalism to describe de Sitter gravitational waves with circular polarization.These results also apply to correlation functions in Anti-de Sitter space. They also describe the general form of stress tensor correlation functions, in momentum space, in a three dimensional conformal field theory. Here all three shapes can arise, including the parity violating one.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/84a70185a3c756c0605969e660a8bdacca3b1e66

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Citations in the corpus

Conformal consistency relations for single-field inflation (2012, background): “In doing this, some derivatives act on the δ-function of momentum conservation, as explained in [3], and give a term with a distribution ∇δ multiplied by the dilation transformation of the correlation function.”
Bootstrapping inflationary correlators in Mellin space (2019, background): “[23, 29, 36, 88, 103, 104, 109, 111, 112, 146–152].”
Conformal Symmetries of Adiabatic Modes in Cosmology (2012, methodology): “This fact has been used recently to derive the form of correlation functions for gravitons [8] and spectator scalar fields [9].”
A natural language for AdS/CFT correlators (2011, background): “Indeed, recently some simple results have been obtained for tensor correlators in momentum space [44].”
The Simons Observatory: science goals and forecasts (2018, background): “Recently, a growing body of work (Maldacena and Pimentel 2011; Lee et al. 2016; Bordin et al. 2016; Baumann et al. 2018; Domènech et al. 2017) has explored the possibility of non-Gaussianities sourced by tensors (Meerburg et al. 2016).”
Shape dependence of entanglement entropy in conformal field theories (2015, unknown): “(9)In three dimensions there is also potentially a parity odd structure [43, 44] that we did not write down.”
Towards Feynman rules for Mellin amplitudes in AdS/CFT (2011, methodology): “Recently there was an attempt to use the spinor-helicity formalism to compactly describe CFT correlators in momentum space [35].”
Late-time structure of the Bunch-Davies de Sitter wavefunction (2014, methodology): “This agrees with several computations of the cubic contribution [69, 70], as well as our general tree level argument in section 4.”
The Cosmological Optical Theorem (2020, methodology): “It has been observed [6, 7] and later discussed e.”
On soft limits of inflationary correlation functions (2012, background): “Being non-linearly realized, the broken symmetry is still reflected in Ward identities relating the squeezed limits of N -point functions to the symmetry variation of (N − 1)-point functions [11, 42, 43].”
Chern–Simons theory with vector fermion matter (2011, background): “In particular, we demonstrate that certain parity odd tensor structures of three point functions recently found in [35,36] arise at one-loop order.”
A note on CFT correlators in three dimensions (2011, background): “Note: Upon completion of the bulk of this work, we became aware of [11] which also observed the parity violating 〈TTT 〉 structure.”
CMB-S4 Science Case, Reference Design, and Project Plan (2019, background): “Although the presence of these couplings is predicted to be small [24, 25] in the simplest inflation models, such a detection would present evidence of exciting new physics [26, 27].”
Causality constraints on corrections to the graviton three-point coupling (2014, methodology): “ton three-point vertex during inflation [17, 20].”