Decay rates of Gaussian-type I-balls and Bose-enhancement effects in 3 + 1 dimensions

Masahiro Kawasaki, Masaki Yamada

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


I-balls/oscillons are long-lived spatially localized lumps of a scalar field which may be formed after inflation. In the scalar field theory with monomial potential nearly and shallower than quadratic, which is motivated by chaotic inflationary models and supersymmetric theories, the scalar field configuration of I-balls is approximately Gaussian. If the I-ball interacts with another scalar field, the I-ball eventually decays into radiation. Recently, it was pointed out that the decay rate of I-balls increases exponentially by the effects of Bose enhancement under some conditions and a non-perturbative method to compute the exponential growth rate has been derived. In this paper, we apply the method to the Gaussian-type I-ball in 3+1 dimensions assuming spherical symmetry, and calculate the partial decay rates into partial waves, labelled by the angular momentum of daughter particles. We reveal the conditions that the I-ball decays exponentially, which are found to depend on the mass and angular momentum of daughter particles and also be affected by the quantum uncertainty in the momentum of daughter particles.

Original languageEnglish
Article number001
JournalJournal of Cosmology and Astroparticle Physics
Issue number2
Publication statusPublished - 2014 Feb
Externally publishedYes


  • cosmological phase transitions
  • ination
  • physics of the early universe
  • supersymmetry and cosmology

ASJC Scopus subject areas

  • Astronomy and Astrophysics


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