English

Do Mixed States save Effective Field Theory from BICEP?

High Energy Physics - Theory 2014-03-24 v2 Cosmology and Nongalactic Astrophysics High Energy Physics - Phenomenology

Abstract

The BICEP2 collaboration has for the first time observed the B-mode polarization associated with inflationary gravitational waves. Their result has some discomfiting implications for the validity of an effective theory approach to single-field inflation since it would require an inflaton field excursion larger than the Planck scale. We argue that if the quantum state of the gravitons is a mixed state based on the Bunch-Davies vacuum, then the tensor to scalar ratio r measured by BICEP is different than the quantity that enters the Lyth bound. When this is taken into account, the tension between effective field theory and the BICEP result is alleviated.

Keywords

Cite

@article{arxiv.1403.4592,
  title  = {Do Mixed States save Effective Field Theory from BICEP?},
  author = {Hael Collins and R. Holman and Tereza Vardanyan},
  journal= {arXiv preprint arXiv:1403.4592},
  year   = {2014}
}

Comments

3 pages, uses RevTeX; v2 Added References, and new paragraph about backreaction

R2 v1 2026-06-22T03:29:24.750Z