TY - JOUR

T1 - Geodesic completeness and homogeneity condition for cosmic inflation

AU - Conroy, Aindriu

AU - S. Koshelev, Alexey

AU - Mazumdar, Anupam

N1 - 4 pages, 1 figure

PY - 2014/8/26

Y1 - 2014/8/26

N2 - There are two disjointed problems in cosmology within General Relativity (GR), which can be addressed simultaneously by studying the nature of geodesics around $t\rightarrow 0$, 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.

AB - There are two disjointed problems in cosmology within General Relativity (GR), which can be addressed simultaneously by studying the nature of geodesics around $t\rightarrow 0$, 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.

KW - gr-qc

KW - astro-ph.CO

KW - hep-th

M3 - Journal article

JO - arxiv.org

JF - arxiv.org

ER -