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Non-Standard cosmological models and the trans-planckian censorship conjecture

Torabian, M ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1002/prop.201900092
  3. Publisher: Wiley-VCH Verlag , 2020
  4. Abstract:
  5. The trans-Planckian censorship conjecture (TCC) puts an upper bound on the life-time of de Sitter spacetimes. It has immediate consequences for inflationary cosmology. In the standard paradigm, the universe has experienced a single stage of inflation and follows a thermal history. Then, the TCC puts an upper bound on the Hubble parameter during inflation Hinf around 0.1 GeV. Consequently, it implies a severe fine-tuning in initial condition for inflation and non-detection of primordial gravitational waves. In this note, we study non-standard cosmological paradigms with non-thermal history and/or multiple stages of inflations. It is motivated by string theory compactifications and axiverse scenarios in which the modulus/axion fields are effective in the early universe. In early matter domination the TCC bound on Hinf can be raised up to 3 orders of magnitude. In multiple inflationary scenarios the upper bound on the observable inflation can be raised up 1014 GeV to touch the Planck 2018 bound. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  6. Keywords:
  7. Inflation ; Non-standard cosmology ; Swampland ; Trans-Planckian censorship
  8. Source: Fortschritte der Physik ; Volume 68, Issue 2 , 2020
  9. URL: https://onlinelibrary.wiley.com/doi/full/10.1002/prop.201900092