Gravitational leptogenesis with kination and gravitational reheating

Kohei Kamada, Jun'Ya Kume, Yusuke Yamada, Jun'Ichi Yokoyama

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


We revisit the gravitational leptogenesis scenario in which the inflaton is coupled to gravity by the Chern-Simons term and the lepton asymmetry is generated through the gravitational anomaly in the lepton number current during inflation. We constrain the possible model parameter space by requiring the absence of ghost modes below the Planck scale, which would suggest the breakdown of the effective theory, and evaluate the net baryon asymmetry for various reheating processes. We find that the mechanism with these requirements is insufficient to explain the observed baryon asymmetry of the Universe for standard reheating scenarios. We show that, however, with the kination scenario realized in e.g. the k- and G-inflation models, a sufficient baryon asymmetry can be generated within a feasible range of the model parameters.

Original languageEnglish
Article number016
JournalJournal of Cosmology and Astroparticle Physics
Issue number1
Publication statusPublished - 2020 Jan 3
Externally publishedYes


  • Inflation
  • Leptogenesis
  • Primordial gravitational waves (theory)

ASJC Scopus subject areas

  • Astronomy and Astrophysics


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