Talk detail

Participant	Parikh , Maulik
Institution	Arizona state university - Department of Physics - Tempe - Arizona - USA

Session	AT3	Accepted	Yes	Order	5	Time	16:30	20'
Talk	Oral abstract	Title	Two Roads to the Null Energy Condition
Coauthors
Abstract	The null energy condition has sweeping consequences in general relativity. We argue here that it has been misunderstood as a property of matter, when in fact it is better viewed as a constraint on spacetime geometry. We then derive precisely the geometric formulation of the null energy condition from worldsheet string theory, where it is simply the Virasoro condition for a closed string moving in a curved background. But further, we show that there is an entirely different thermodynamic origin of the null energy condition, if gravity emerges from some holographic theory. Thus, rather than being an incidental property of matter, the validity of the null energy condition appears to hint at the origins of gravity.
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Session	ES3	Accepted	Yes	Order	8	Time	16:45	15'
Talk	Oral abstract	Title	The Physical Origin of the Null Energy Condition
Coauthors
Abstract	The energy conditions are seemingly reasonable but ad hoc assumptions about matter that are used to greatly constrain the set of physical solutions to Einstein's equations. However, the energy conditions have thus far lacked a physical origin. Here I derive the null energy condition from first principles in two different ways. This at last provides a physical basis for the most important local constraint on solutions of Einstein's equations.
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Session	BH5	Accepted	Yes	Order	7	Time	17:20	20'
Talk	Oral abstract	Title	The Volume of Black Holes
Coauthors
Abstract	We propose a simple definition of volume for stationary spacetimes. The proposed volume is constant in time, independent of the choice of stationary time slicing, and applies even in the absence of a globally timelike Killing vector. If time permits, we will also discuss the effect of topology on black hole nucleation.
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Session	ST2	Accepted	Yes	Order	10	Time	18:15	20'
Talk	Oral abstract	Title	Rindler-AdS/CFT
Coauthors
Abstract	In anti-de Sitter space a highly accelerating observer perceives a Rindler horizon. For AdS3, the holographic duality is especially tractable, allowing quantum-gravitational aspects of Rindler horizons to be probed. We recover the thermodynamics of Rindler-AdS space directly from the boundary conformal field theory. We derive the temperature from the two-point function and obtain the Rindler entropy density precisely, including numerical factors, using the Cardy formula. We also probe the causal structure of the spacetime, and find from the behavior of the one-point function that the CFT “knows” when a source has fallen across the Rindler horizon.
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