Geodesic completeness and homogeneity condition for cosmic inflation

Abstract

There are two disjointed problems in cosmology within General Relativity (GR), which can be addressed simultaneously by studying the nature of geodesics around $t\to 0$, where $t$ is the physical time. One is related to the past geodesic completeness of the inflationary trajectory due to the presence of a cosmological singularity, and the other one is related to the homogeneity condition required to inflate a local space-time patch of the universe. We will show that both the problems have a common origin, arising from how the causal structure of null and timelike geodesics are structured within GR. In particular, we will show how a non-local extension of GR can address both problems, while satisfying the null energy condition for the matter sources.

4 pages, 1 figure

References in corpus (4)

• Towards a Resolution of the Cosmological Singularity in Non-local Higher Derivative Theories of Gravity
• Black holes in an ultraviolet complete quantum gravity
• Route to nonlocal cosmology
• Inflating an Inhomogeneous Universe

Cited by in corpus (4)

• Wald's gravitational entropy for ghost-free, infinite derivative theories of Gravity
• On Nonlocal Modified Gravity and its Cosmological Solutions
• Newtonian Potential and Geodesic Completeness in Infinite Derivative Gravity
• Criteria for resolving the cosmological singularity in Infinite Derivative Gravity around expanding backgrounds