Venue  Zewail University Invited Speaksers Series      Location  Center for Fundamental Phyiscs, Zewail City for Science & Technology | Nano S31
Date  9-10 August 2026      Time  2:00 PM

Talk Material

◈  This is a blackboard talk. No digital material is available.

◈  Related literature: arXiv:1408.3203, arXiv:2006.06872, arXiv:2607.26194, arXiv:2311.12921, arXiv:1912.00228, arXiv:2208.04993.

Abstract

The black hole information paradox arises from an apparent conflict between Hawking’s semiclassical calculation of black hole evaporation and the unitary evolution expected in quantum mechanics. In this talk, I will review the origin of the paradox, the role of entanglement and the Page curve, and the assumptions underlying the sharpest formulations of the problem. I will then discuss recent developments based on modern concepts like quantum extremal surfaces, the island formula, and replica wormholes, which reproduce a unitary Page curve in controlled models of evaporating black holes. I will emphasize both what these results appear to establish and what remains unclear, including the microscopic mechanism by which information is recovered, the reconstruction of the black hole interior, the interpretation of replica wormholes, and the extension of these ideas to realistic four-dimensional black holes. The goal is to provide a broad overview of how our understanding of the information paradox has changed and which questions remain open.

Mr. Hassan ElSayed is a theoretical physicist specializing in gravity, black hole thermodynamics, and high-energy physics. He is currently pursuing a Ph.D. in Physics at the University of Wisconsin-Madison, following an M.Sc. in Physics from the University of Connecticut and an earlier M.Sc. in Telecommunications Engineering from Sorbonne University and Télécom Paris. His research focuses on quantum gravity, black hole physics, and differential geometry, and he has previously worked as a research assistant at CNRS (France) and the American University in Cairo.

Venue  UConn Chalk Talks Series      Location  UConn, Storrs Campus, GS119

Talk Material

◈  The lectures are based on my notes which can be found here.

Abstract

A series of colloquial lectures on general relativity and differential geometry.

Venue  UConn PAN Seminars Location  UConn, Storrs Campus, GS119 Date 10/24/2022 Time  2-3 PM Official Link

Talk Material

◈  Presentation

◈  UConn Physics LaTeX template

Abstract

Black hole thermodynamics has applications related to all physics research groups at UConn. From the point of view of astrophysics, for example, black hole thermodynamics allows the study of black hole phase transitions, and can be used in studying binary black hole mergers. From the point of view of high energy physics, it is our clearest gateway at the moment to understanding quantum gravity. This is possible thanks to the anti-de Sitter/conformal field theory (AdS/CFT) correspondence. The latter is a correspondence between black hole solutions arising from string theory in a weak-coupling regime and a particular class of quantum field theories in a strong-coupling regime. The AdS/CFT correspondence thus finds applications in condensed matter physics, AMO physics and QCD. Particularly, it allows us to massively simplify certain calculations by doing the analysis in a weak-coupling regime instead of a strong-coupling one.

In this talk, I will explain the major ideas behind the thermodynamics of black holes, and how they relate to the traditional laws of thermodynamics. Following that, I will give a brief overview of the Holographic Principle and its embodiment in the AdS/CFT correspondence. Finally, I will discuss my research on a class of black holes in five-dimensional AdS spacetime [arXiv:2209.09031]. In this research we have demonstrated some conjectured relations between these black holes and the conformal field theories on the boundary. We have also extended an earlier analysis by Papadimitriou and Skenderis [arXiv:hep-th/0505190] to solve a long-standing problem with the first law of thermodynamics in extended phase-space and the generalized Smarr relation.

Venue  Fall Meeting of the APS New England Section      Location  U. of New Hampshire, Durham Campus      Date 10/15/2022       Time  1-3 PM 

Official Link

Talk Material

◈  Presentation

◈  Paper link

Abstract

In this talk I will present the results that we recently reported in arXiv:2209.0903. In this research we proposed a solution to a long-standing problem with the compatibility of the counterterms subtraction method with the 1st law and generalized Smarr’s formula in extended phase-space. We used the counterterms subtraction method to calculate various thermodynamical quantities for charged rotating black holes in five-dimensional minimal gauged supergravity. Specifically, we analyzed certain issues related to the first law and Smarr's relation in the presence of a conformal anomaly. Among the bulk quantities calculated are the on-shell action, total mass, and angular momenta of the solution. All these quantities are consistent with previous calculations made using other methods. For the boundary theory, we calculate the renormalized stress tensor, conformal anomaly, and Casimir energy. Using the Papadimitriou-Skenderis analysis [arXiv:hep-th/0505190], we showed that the mass calculated via the counterterms method satisfies the first law of black hole thermodynamics. To discuss extended thermodynamics, we extended the definition of the thermodynamic volume to cases with conformal anomalies using a procedure similar to that of Papadimitriou-Skenderis. We showed that this volume correctly accounts for extra terms due to boundary metric variation. This shows that the mass and volume calculated using counterterms satisfy Smarr’s relation as well as the first law.