Singular instantons in EddingtoninspiredBornInfeld gravity
In this study, we investigate O(4)symmetric instantons within the EddingtoninspiredBornInfeld gravity theory (EiBI) . We discuss the regular HawkingMoss instanton and find that the tunneling rate reduces to the General Relativity (GR) value, even though the action value is different by a constant. We give a thorough analysis of the singular Vilenkin instanton and the HawkingTurok instanton with a quadratic scalar field potential in the EiBI theory. In both cases, we find that the singularity can be avoided in the sense that the physical metric, its scalar curvature and the scalar field are regular under some parameter restrictions, but there is a curvature singularity of the auxiliary metric compatible with the connection. We find that the onshell action is finite and the probability does not reduce to its GR value. We also find that the Vilenkin instanton in the EiBI theory would still cause the instability of the Minkowski space, similar to that in GR, and this is observationally inconsistent. This result suggests that the singularity of the auxiliary metric may be problematic at the quantum level and that these instantons should be excluded from the path integral.
 Authors:

^{[1]};
^{[1]};
^{[2]};
^{[1]}
 National Taiwan Univ., Taipei (Taiwan)
 National Taiwan Univ., Taipei (Taiwan); Stanford, CA (United States). SLAC National Accelerator Lab.Stanford Univ.
 Publication Date:
 Grant/Contract Number:
 AC0276SF00515
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Cosmology and Astroparticle Physics
 Additional Journal Information:
 Journal Volume: 2017; Journal Issue: 03; Journal ID: ISSN 14757516
 Publisher:
 Institute of Physics (IOP)
 Research Org:
 SLAC National Accelerator Lab., Menlo Park, CA (United States)
 Sponsoring Org:
 USDOE
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTRONOMY AND ASTROPHYSICS; modified gravity; quantum cosmology; physics of the early universe
 OSTI Identifier:
 1374375
Arroja, Frederico, Chen, Che Yu, Chen, Pisin, and Yeom, Donghan. Singular instantons in EddingtoninspiredBornInfeld gravity. United States: N. p.,
Web. doi:10.1088/14757516/2017/03/044.
Arroja, Frederico, Chen, Che Yu, Chen, Pisin, & Yeom, Donghan. Singular instantons in EddingtoninspiredBornInfeld gravity. United States. doi:10.1088/14757516/2017/03/044.
Arroja, Frederico, Chen, Che Yu, Chen, Pisin, and Yeom, Donghan. 2017.
"Singular instantons in EddingtoninspiredBornInfeld gravity". United States.
doi:10.1088/14757516/2017/03/044. https://www.osti.gov/servlets/purl/1374375.
@article{osti_1374375,
title = {Singular instantons in EddingtoninspiredBornInfeld gravity},
author = {Arroja, Frederico and Chen, Che Yu and Chen, Pisin and Yeom, Donghan},
abstractNote = {In this study, we investigate O(4)symmetric instantons within the EddingtoninspiredBornInfeld gravity theory (EiBI) . We discuss the regular HawkingMoss instanton and find that the tunneling rate reduces to the General Relativity (GR) value, even though the action value is different by a constant. We give a thorough analysis of the singular Vilenkin instanton and the HawkingTurok instanton with a quadratic scalar field potential in the EiBI theory. In both cases, we find that the singularity can be avoided in the sense that the physical metric, its scalar curvature and the scalar field are regular under some parameter restrictions, but there is a curvature singularity of the auxiliary metric compatible with the connection. We find that the onshell action is finite and the probability does not reduce to its GR value. We also find that the Vilenkin instanton in the EiBI theory would still cause the instability of the Minkowski space, similar to that in GR, and this is observationally inconsistent. This result suggests that the singularity of the auxiliary metric may be problematic at the quantum level and that these instantons should be excluded from the path integral.},
doi = {10.1088/14757516/2017/03/044},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 03,
volume = 2017,
place = {United States},
year = {2017},
month = {3}
}