Some remarks on anthropic approaches to the strong CP problem
Abstract
The peculiar value of θ is a challenge to the notion of an anthropic landscape. We briefly review the possibility that a suitable axion might arise from an anthropic requirement of dark matter. We then consider an alternative suggestion of Kaloper and Terning that θ might be correlated with the cosmological constant. We note that in a landscape one expects that θ is determined by the expectation value of one or more axions. We discuss how a discretuum of values of θ might arise with an energy distribution dominated by QCD, and find the requirements to be quite stringent. Given such a discretuum, we find no circumstances where small θ might be selected by anthropic requirements on the cosmological constant.
 Authors:

 Univ. of California, Santa Cruz, CA (United States). Santa Cruz Inst. for Particle Physics and Dept. of Physics
 Hebrew Univ. of Jerusalem (Israel). Racah Inst. of Physics
 SISSA International School for Advanced Studies, Trieste (Italy)
 Publication Date:
 Research Org.:
 Univ. of California, Santa Cruz, CA (United States)
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 1507771
 Grant/Contract Number:
 FG0204ER41286
 Resource Type:
 Accepted Manuscript
 Journal Name:
 Journal of High Energy Physics (Online)
 Additional Journal Information:
 Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2018; Journal Issue: 5; Journal ID: ISSN 10298479
 Publisher:
 Springer Berlin
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; QCD Phenomenology
Citation Formats
Dine, Michael, Haskins, Laurel Stephenson, Ubaldi, Lorenzo, and Xu, Di. Some remarks on anthropic approaches to the strong CP problem. United States: N. p., 2018.
Web. doi:10.1007/jhep05(2018)171.
Dine, Michael, Haskins, Laurel Stephenson, Ubaldi, Lorenzo, & Xu, Di. Some remarks on anthropic approaches to the strong CP problem. United States. https://doi.org/10.1007/jhep05(2018)171
Dine, Michael, Haskins, Laurel Stephenson, Ubaldi, Lorenzo, and Xu, Di. Mon .
"Some remarks on anthropic approaches to the strong CP problem". United States. https://doi.org/10.1007/jhep05(2018)171. https://www.osti.gov/servlets/purl/1507771.
@article{osti_1507771,
title = {Some remarks on anthropic approaches to the strong CP problem},
author = {Dine, Michael and Haskins, Laurel Stephenson and Ubaldi, Lorenzo and Xu, Di},
abstractNote = {The peculiar value of θ is a challenge to the notion of an anthropic landscape. We briefly review the possibility that a suitable axion might arise from an anthropic requirement of dark matter. We then consider an alternative suggestion of Kaloper and Terning that θ might be correlated with the cosmological constant. We note that in a landscape one expects that θ is determined by the expectation value of one or more axions. We discuss how a discretuum of values of θ might arise with an energy distribution dominated by QCD, and find the requirements to be quite stringent. Given such a discretuum, we find no circumstances where small θ might be selected by anthropic requirements on the cosmological constant.},
doi = {10.1007/jhep05(2018)171},
journal = {Journal of High Energy Physics (Online)},
number = 5,
volume = 2018,
place = {United States},
year = {2018},
month = {5}
}
Web of Science
Figures / Tables:
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