Talk detail

Participant	LOCHAN, KINJALK
Institution	Inter-University Centre for Astronomy and Astrophysics - Ganeshkhind - Pune - Maharashtra - India

Session	BH6	Accepted		Order	Time
Talk	Oral abstract	Title	QFT on curved spacetime with non vacuum states : Implications for Hawking radiation
Coauthors
Abstract	We present a general formalism describing characterization of an arbitrary inertial state for a quantum field on arbitrary space-time. We demonstrate the technique for Rindler observers. This has a direct implication for spectrum of Hawking radiation from black holes. We show that any arbitrary in-state will always have a thermal component with additional contributions arising from the non-vacuum nature of the in-state. We classify the nature of the additional contributions in terms of functions characterizing the in-state. The complete information about the in-state is generally not encoded in the resulting Hawking radiation and hence is non-retrievable. However, we identify a class of in-states capable of doing so. We show that for a large class of in-states, some particular observables on the initial Hilbert space generically get fixed from the resulting spectrum. We also show that for some special class of states, some other interesting quantities can also be obtained. We argue that a semi-classical collapse scenario forgets about this richness of information in the resulting spectrum and a consistent full quantum treatment is warranted. [Ref: Phys.Rev. D 91 (2015) 4, 044002]
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Session	QG2	Accepted		Order	Time
Talk	Oral abstract	Title	Gravitational Lensing by Self-Dual Black Holes in Loop Quantum Gravity
Coauthors
Abstract	We study gravitational lensing by a recently proposed black hole solution in Loop Quantum Gravity. We highlight the fact that the quantum gravity corrections to the Schwarzschild metric in this model evade the `mass suppression' effects (that the usual quantum gravity corrections are susceptible to) by virtue of one of the parameters in the model being dimensionless, which is unlike any other quantum gravity motivated parameter. Gravitational lensing in the strong and weak deflection regimes is studied and a sample consistency relation is presented which could serve as a test of this model. We discuss that though the consistency relation for this model is qualitatively similar to what would have been in Brans-Dicke, in general it can be a good discriminator between many alternative theories. Although the observational prospects do not seem to be very optimistic even for a galactic supermassive black hole case, time delay between relativistic images for billion solar mass black holes in other galaxies might be within reach of future relativistic lensing observations. [Ref: Phys. Rev. D 91, 063001 (2015)]
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