Departmental Oral Examination (Thesis Title: "Energy, Entropy and Spacetime: Lessons from Semiclassical Black Holes")

Event Date:
2019-06-07T12:00:00
2019-06-07T14:00:00
Event Location:
Room 309, Hennings Bldg
Speaker:
BRUNO ARDERUCIO COSTA
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Intended Audience:
Public
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Department of Physics and Astronomy

Event Information:

Thesis Abstract:
This doctoral thesis explores semiclassical effects on black hole physics. Semiclassical theory refers as the application of quantum field theory in curved, classical background geometries, which respond to the expectation value of the regularised stress-energy tensor of the quantum matter.

Among the original findings, I develop a few useful techniques to help regularising the stress-energy tensor in two dimensions; and their application to a model of stellar collapse to analyse the importance of quantum mechanical effects in the collapse itself. I found an explicit example showing that the behaviour of the late-times Hawking radiation does not depend on the details of the collapse and argued that any quantum mechanical effect is negligible for the collapse of an astrophysical object (whose mass is comparable to the solar mass).
In the realm of black hole thermodynamics, I proved its first law for stationary black holes, proposed a definition for the entropy in piecewise stationary black holes which I showed to obey the generalised second law of thermodynamics. After also discussing its zeroth law, it becomes clear that this set of laws are originated in the semiclassical approach and it is made clear which hypothesis are necessary for these laws to hold. The derivation of these laws also point towards the long-standing question of the interpretation of the Bekenstein-Hawking entropy as accounting from the information perspective.

Add to Calendar 2019-06-07T12:00:00 2019-06-07T14:00:00 Departmental Oral Examination (Thesis Title: "Energy, Entropy and Spacetime: Lessons from Semiclassical Black Holes") Event Information: Thesis Abstract: This doctoral thesis explores semiclassical effects on black hole physics. Semiclassical theory refers as the application of quantum field theory in curved, classical background geometries, which respond to the expectation value of the regularised stress-energy tensor of the quantum matter. Among the original findings, I develop a few useful techniques to help regularising the stress-energy tensor in two dimensions; and their application to a model of stellar collapse to analyse the importance of quantum mechanical effects in the collapse itself. I found an explicit example showing that the behaviour of the late-times Hawking radiation does not depend on the details of the collapse and argued that any quantum mechanical effect is negligible for the collapse of an astrophysical object (whose mass is comparable to the solar mass). In the realm of black hole thermodynamics, I proved its first law for stationary black holes, proposed a definition for the entropy in piecewise stationary black holes which I showed to obey the generalised second law of thermodynamics. After also discussing its zeroth law, it becomes clear that this set of laws are originated in the semiclassical approach and it is made clear which hypothesis are necessary for these laws to hold. The derivation of these laws also point towards the long-standing question of the interpretation of the Bekenstein-Hawking entropy as accounting from the information perspective. Event Location: Room 309, Hennings Bldg