English

Large-$\eta$ Constant-Roll Inflation Is Never An Attractor

Cosmology and Nongalactic Astrophysics 2018-06-20 v2 General Relativity and Quantum Cosmology

Abstract

Slow roll solutions to inflationary potentials have been widely believed to be the only universal attractor. Over the last few years there has been growing interest in a new class of inflationary models known as Constant-Roll Inflation. Constant roll solutions are a generalization of "ultra-slow roll" dynamics, where the first slow roll parameter is small, but the second slow roll parameter η\eta is larger than unity. In Ultra-slow Roll Inflation, the large-η\eta solution is a dynamical transient, relaxing exponentially to the attractor de Sitter solution. In the constant roll generalization, recent papers have concluded that Constant-Roll Inflation represents a new class of non-slow roll attractor solutions. In this paper we show that these attractor solutions are actually the usual slow roll attractor, disguised by a parameter duality, and that the large-η\eta solutions, as in the case of ultra-slow roll, represent a dynamical transient.

Cite

@article{arxiv.1804.01927,
  title  = {Large-$\eta$ Constant-Roll Inflation Is Never An Attractor},
  author = {Michael J. P. Morse and William H. Kinney},
  journal= {arXiv preprint arXiv:1804.01927},
  year   = {2018}
}

Comments

8 pages, no figures, V2: References added. Version submitted to PRD

R2 v1 2026-06-23T01:15:09.868Z