Hassan’s Web Home

About This Website

This website is a way for me to share some content that I made in different areas of physics in an effort to help physics enthusiasts, undergraduate and other graduate students.

About This Person

I am an Egyptian grad student at the University of Wisconsin-Madison. I like physics, math, puzzles, music – as well as sharing what I know about these things with others! 

Scientific Interests

I am currently working on applications from differential geometry to quantum gravity, particularly on
        quantum extremal surfaces [arXiv:1408.3203] and the generalized entropy.

My previous research experience in engineering was as a grad student-researcher at the CNRS/Paris
Observatory, where I worked with Dr. Moustapha Dekkali to develop a new topology for
telecommunication chains that is suitable for space exploration missions. (Cf. arXiv:2209.11742
[astro-ph.IM])

I also worked for 4 years as a software engineer where I developed buisness and financial solutions,
giving me substantial experience with programming and modeling.

Musical Interests

I have been playing classical and flamenco guitars for a little over 17 years now. I also spent a few
years teaching classical guitar and music theory at the Kythara Institute in Cairo. This was a nice
experience as I dealt with students as young as 5 years all the way up to students that were a few
years older than me.

Links

  arXiv

  ORCiD

◉   My UW-Madison page

A rare photo of me with grandpa

Talks

General Relativity Lectures @ UConn Chalk Talks

Venue  UConn Chalk Talks Series Location  UConn, Storrs Campus, GS119 Date TBA Time  TBA


Talk Material

 TBA

Abstract

TBA

Black Hole Thermodynamics and Counterterms in AdS5

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.

The First Law in AdS5 in the Presence of Conformal Anomalies

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 Smarrs relation as well as the first law.

~.~.~.~.

Contact

       Email: hassan.elsayed [at] wisc.edu
       Office: Chamberlin Hall #4250