Tensor modes in pure natural inflation
We study tensor modes in pure natural inflation, a recentlyproposed inflationary model in which an axionic inflaton couples to pure Yang–Mills gauge fields. We find that the tensortoscalar ratio r is naturally bounded from below. This bound originates from the finiteness of the number of metastable branches of vacua in pure Yang–Mills theories. Details of the model can be probed by future cosmic microwave background experiments and improved lattice gauge theory calculations of the θangle dependence of the vacuum energy.
 Authors:

^{[1]}
;
^{[2]}
 Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of Tokyo, Chiba (Japan)
 Univ. of Tokyo, Chiba (Japan)
 Publication Date:
 Grant/Contract Number:
 AC0205CH11231; 15K17634
 Type:
 Published Article
 Journal Name:
 Physics Letters. Section B
 Additional Journal Information:
 Journal Volume: 780; Journal Issue: C; Related Information: © 2018; Journal ID: ISSN 03702693
 Publisher:
 Elsevier
 Research Org:
 Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), High Energy Physics (HEP) (SC25)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
 OSTI Identifier:
 1423905
 Alternate Identifier(s):
 OSTI ID: 1461997
Nomura, Yasunori, and Yamazaki, Masahito. Tensor modes in pure natural inflation. United States: N. p.,
Web. doi:10.1016/j.physletb.2018.02.071.
Nomura, Yasunori, & Yamazaki, Masahito. Tensor modes in pure natural inflation. United States. doi:10.1016/j.physletb.2018.02.071.
Nomura, Yasunori, and Yamazaki, Masahito. 2018.
"Tensor modes in pure natural inflation". United States.
doi:10.1016/j.physletb.2018.02.071.
@article{osti_1423905,
title = {Tensor modes in pure natural inflation},
author = {Nomura, Yasunori and Yamazaki, Masahito},
abstractNote = {We study tensor modes in pure natural inflation, a recentlyproposed inflationary model in which an axionic inflaton couples to pure Yang–Mills gauge fields. We find that the tensortoscalar ratio r is naturally bounded from below. This bound originates from the finiteness of the number of metastable branches of vacua in pure Yang–Mills theories. Details of the model can be probed by future cosmic microwave background experiments and improved lattice gauge theory calculations of the θangle dependence of the vacuum energy.},
doi = {10.1016/j.physletb.2018.02.071},
journal = {Physics Letters. Section B},
number = C,
volume = 780,
place = {United States},
year = {2018},
month = {3}
}