Talk detail

Participant	Mazumdar, Anupam
Institution	Lancaster University - Physics Department - Lancaster - Lancaster - United Kingdom

Session	EU3	Accepted		Order	Time
Talk	Oral abstract	Title	Focusing theorem in non-local gravity and its applications for avoiding cosmological singularity problem
Coauthors
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.
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Session	ST3	Accepted		Order	Time
Talk	Oral abstract	Title	Ground state of gravity and holographic interpretation of gravity
Coauthors
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.
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