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dc.contributor.authorAnderson, David
dc.contributor.authorYunes, Nicolás
dc.date.accessioned2018-02-16T19:19:29Z
dc.date.available2018-02-16T19:19:29Z
dc.date.issued2017-09
dc.identifier.citationAnderson, David, and Nicolas Yunes. "Solar System constraints on massless scalar-tensor gravity with positive coupling constant upon cosmological evolution of the scalar field." Physical Review D 96, no. 6 (September 2017): 1-20. DOI:https://dx.doi.org/10.1103/PhysRevD.96.064037.en_US
dc.identifier.issn2470-0010
dc.identifier.urihttps://scholarworks.montana.edu/xmlui/handle/1/14377
dc.description.abstractScalar-tensor theories of gravity modify general relativity by introducing a scalar field that couples nonminimally to the metric tensor, while satisfying the weak-equivalence principle. These theories are interesting because they have the potential to simultaneously suppress modifications to Einstein\'s theory on Solar System scales, while introducing large deviations in the strong field of neutron stars. Scalar-tensor theories can be classified through the choice of conformal factor, a scalar that regulates the coupling between matter and the metric in the Einstein frame. The class defined by a Gaussian conformal factor with a negative exponent has been studied the most because it leads to spontaneous scalarization (i.e. the sudden activation of the scalar field in neutron stars), which consequently leads to large deviations from general relativity in the strong field. This class, however, has recently been shown to be in conflict with Solar System observations when accounting for the cosmological evolution of the scalar field. We here study whether this remains the case when the exponent of the conformal factor is positive, as well as in another class of theories defined by a hyperbolic conformal factor. We find that in both of these scalar-tensor theories, Solar System tests are passed only in a very small subset of coupling parameter space, for a large set of initial conditions compatible with big bang nucleosynthesis. However, while we find that it is possible for neutron stars to scalarize, one must carefully select the coupling parameter to do so, and even then, the scalar charge is typically 2 orders of magnitude smaller than in the negative-exponent case. Our study suggests that future work on scalar-tensor gravity, for example in the context of tests of general relativity with gravitational waves from neutron star binaries, should be carried out within the positive coupling parameter class.en_US
dc.description.sponsorshipNSF CAREER PHY-1250636; NASA NNX16AB98G;en_US
dc.rightsNOT OAen_US
dc.titleSolar System constraints on massless scalar-tensor gravity with positive coupling constant upon cosmological evolution of the scalar fielden_US
mus.citation.extentfirstpage1en_US
mus.citation.extentlastpage20en_US
mus.citation.issue6en_US
mus.citation.journaltitlePhysical Review Den_US
mus.citation.volume96en_US
mus.identifier.categoryPhysics & Mathematicsen_US
mus.identifier.doi10.1103/PhysRevD.96.064037en_US
mus.relation.collegeCollege of Letters & Scienceen_US
mus.relation.departmentPhysics.en_US
mus.relation.universityMontana State University - Bozemanen_US
mus.data.thumbpage2en_US


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