Stronger gravity in the early universe
Abstract
Scalartensor theories of gravity that embrace conformal coupling to the scalar curvature are the focal point of cosmology on discussions of inflation and latetime accelerating universe. Although there exists a stringent nucleosynthesis constraint on conformal gravity, one can formulate how to evade this difficulty by modifying the standard particle theory action consistently with the principles of gauge invariant quantum field theory. It is shown that stronger gravity at early epochs of cosmological evolution than previously thought of is inevitable in a class of conformal gravity models. This enhances discovery potentials of primordial gravitational wave emission and primordial black hole formation. The strong gravity effect may be enormous if massive clumps are energetically dominated by cold dark matter made of inflaton field, and created black holes may become a major candidate of cold dark matter.
 Publication:

arXiv eprints
 Pub Date:
 April 2022
 DOI:
 10.48550/arXiv.2204.11384
 arXiv:
 arXiv:2204.11384
 Bibcode:
 2022arXiv220411384Y
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 5 pages