English

The non-adiabatic pressure in general scalar field systems

Astrophysics 2010-01-07 v3

Abstract

We discuss the non-adiabatic or entropy perturbation, which controls the evolution of the curvature perturbation in the uniform density gauge, for a scalar field system minimally coupled to gravity with non-canonical action. We highlight the differences between the sound and the phase speed in these systems, and show that the non-adiabatic pressure perturbation vanishes in the single field case, resulting in the conservation of the curvature perturbation on large scales.

Keywords

Cite

@article{arxiv.0809.3518,
  title  = {The non-adiabatic pressure in general scalar field systems},
  author = {Adam J. Christopherson and Karim A. Malik},
  journal= {arXiv preprint arXiv:0809.3518},
  year   = {2010}
}

Comments

6 pages, revtex4; v2: typos corrected, results clarified, version being submitted; v3: version accepted for publication