2020/04/30 by Lorenzo Bordin, Giovanni Cabass
Physics and Astronomy · #Bispectrum #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Graviton #Inflation (cosmology) #Noncommutative and Quantum Gravity Theories #Operator (biology) #Order (exchange) #Parity (physics) #Slow roll #astro-ph.CO #hep-ph
paper · pdf · doi:10.1088/1475-7516/2020/07/014
21 pages (15+6). v3: added a section on soft limits, a more detailed discussion on the $M^2_{\rm P}A_{\rm s}/Λ^2\gg 1$ limit, and comments in light of "boostless cosmological bootstrap" program
openalex created_date 2020/04/10 · openalex publication_date 2020/07/06 · arxiv created 2020/11/17 · arxiv updated 2020/11/19 · openalex updated_date 2026/08/05
We study graviton non-Gaussianities in the EFT of Inflation. At leading (second) order in derivatives, the graviton bispectrum is fixed by Einstein gravity. There are only two contributions at third order. One of them breaks parity. They come from operators that directly involve the foliation: we then expect sizable non-Gaussianities in three-point functions involving both gravitons and scalars. However, we show that at leading order in slow roll the parity-odd operator does not modify these mixed correlators. We then identify the operators that can affect the graviton bispectrum at fourth order in derivatives. There are two operators that preserve parity. We show that one gives a scalar-tensor-tensor three-point function larger than the one computed in Maldacena, 2003 [1] if M 2 P A s /Λ 2≫ 1 (where Λ is the scale suppressing this operator and A s the amplitude of the scalar power spectrum). There are only two parity-odd operators at this order in derivatives.