Talk detail

MG14 - Talk detail

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 Participant

Mazumdar, Anupam

Institution

Lancaster University  - Physics Department - Lancaster - Lancaster - United Kingdom

Session

EU3

Accepted

Yes

Order

7

Time

17:10 15'

Talk

Oral abstract

Title

Focusing theorem in non-local gravity and its applications for avoiding cosmological singularity problem
Coauthors Tirthabir Biswas, Aindriu Conroy, Alexey Koshelev, Tomi Koivisto

Abstract

I will discuss how to modify gravity in the ultraviolet which becomes ghost free and singularity free theory of gravity by following the non-local prescription given by Biswas-Gerwick-Koivisto and Mazumdar (BGKM). I will show how an infinite derivative theory of gravity becomes non-local and how it can smoothen the singular sources and modify the ultraviolet aspects of gravity. In particular, I will revisit the focusing theorem for gravity by Penrose and Hawking for non-local, ghost free and singularity free theory of gravity, and I will show how BGKM gravity can resolve cosmological singularity problem for a spatially flat background with all energy conditions, such as strong, weak and null energy conditions remain intact. Finally, I will construct non-singular bouncing cosmology, which is stable under linear perturbations, and will discuss smoking gun signature of such non-singular cosmology present within WMAP and Planck data for cosmic microwave background radiation.

Pdf file

pdf file 

Session

ST3

Accepted

Yes

Order

10

Time

18:25 5'

Talk

Oral abstract

Title

Ground state of gravity and holographic interpretation of gravity
Coauthors Aindriu Conroy, Ali Teimouri

Abstract

In this talk, I will demonstrate that the Wald’s entropy for any spherically symmetric blackhole within an infinite derivative theory of gravity, which is ghost free and singularity free theory of gravity is determined solely by the area law. Thus, the infrared behaviour of gravity is captured by the Einstein-Hilbert term, provided that the massless graviton remains the only propagating degree of freedom in the spacetime. In the ultraviolet the Wald's entropy vanishes identically, suggesting that graviton excitation vanishes identically, and so it the gravitational entropy. A deep connection can be built based on gauge theory and such gravity within anti-de Sitter space which I will discuss briefly in my talk.

Pdf file

pdf file 

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