Loading...

Derivative interactions during inflation: A systematic approach

Abolhasani, A ; Sharif University of Technology | 2022

41 Viewed
  1. Type of Document: Article
  2. DOI: 10.1088/1475-7516/2022/06/032
  3. Publisher: Institute of Physics , 2022
  4. Abstract:
  5. We present a systematic prescription for calculating cosmological correlation functions for models with derivative interactions through the wavefunction of the universe and compare this result with the "in-in"formalism - canonical approach. The key step in this procedure is to perform the path integral over conjugate momenta after which a straightforward generalisation of Feynman's Rules can be applied. We show that this integral recovers the classical action plus some additional divergent contributions which are necessary to cancel other divergences that arise due to loop diagrams involving time derivatives. As a side project, for the first time, we introduce the "off-shell"version of the in-in formalism that is sometimes more straightforward, especially for the models with derivative coupling. To examine our prescription, as a specific example, we work out the trispectra of the scalar fluctuation in the model with the λφ' 3 derivative coupling. © 2022 IOP Publishing Ltd and Sissa Medialab
  6. Keywords:
  7. Cosmological perturbation theory ; Inflation ; Physics of the early universe ; Quantum cosmology
  8. Source: Journal of Cosmology and Astroparticle Physics ; Volume 2022, Issue 6 , 2022 ; 14757516 (ISSN)
  9. URL: https://iopscience.iop.org/article/10.1088/1475-7516/2022/06/032