Group Meetings
Published by admin on Monday, March 1, 2010
The Gravity Group at UMississippi has a regular weekly scheduled meeting throughout the year to discuss current research progress, topics of interest and new papers. Typically, each week, two members of the group each make a short presentation, either about their current area of research or a paper that has attracted their interest.
For Summer 2025, the Group meets on Wednesdays at 11AM-12PM for a journal club and on Fridays at 11AM-12PM for a research update, both a scheduled ca. half hour presentation and room for free-form updates. The schedule of speakers for this period is:
Group Meeting Schedule(*subject to change)
| Date | Paper Presentation | Reseach Update |
|---|---|---|
| Sept 4 | Dipika | Francesco |
| Sept 11 | Subhayu | Nauman |
| Sept 18 | Aniket | Leo |
| Sept 25 | James | Ahmed |
| Sept 29 | Seminar | Seminar |
| Oct 2 | Arindam | Subhayu |
| Oct 9 | Seminar | Seminar |
| Oct 16 | Leo | Amitesh |
| Oct 23 | Seminar | Seminar |
| Oct 30 | Nauman | Aniket |
| Nov 6 | Seminar | Seminar |
| Nov 13 | Amitesh | Dipika |
| Nov 20 | Gokul | Arindam |
| Dec 4 | Anuradha | James |
The group also has a running series where an external speaker is invited to give seminar talk during one of the usual meetings on their area of research or any topic of interest. The seminar then replaces the usual format of the meetings on those days. The list of external speakers will be updated as time goes on.
Tentative List of Seminars(*subject to change)
| Date | Speaker | Affiliation | Title of talk |
|---|---|---|---|
| Sept 29 | Chris Kavanagh | University College Dublin | Progress and prospects with analytic perturbation theory for small mass-ratio compact binaries. |
| Oct 9 | Maxence Corman | AEI Potsdam | Nonlinear dynamics of compact object mergers beyond General Relativity |
| Oct 23 | Nils Siemonsen | Princeton University | Ergoregion instability: the nonlinear story |
| Nov 6 | Marica Minucci | NBI, Copenhagen | Title |
The next scheduled seminar speaker is .
Title:
Ergoregion instability: the nonlinear story
Abstract:
All current gravitational wave and electromagnetic observations of ultra compact objects are remarkably consistent with the black hole hypothesis. However, to critically analyze what it means to observe a black hole, one needs to entertain horizonless alternatives to the black hole paradigm. Compact, spinning, and horizonless spacetimes can develop an ergoregion, where massless negative-energy states are quasi-trapped and drive the ergoregion instability. I will briefly review the linear mechanism and then describe recent progress in understanding the nonlinear evolution. Nonlinear mode coupling can amplify high-frequency modes through a turbulent direct cascade inside the ergoregion. Gravitational backreaction leads to an enhancement of the unstable process, and ultimately, black hole formation. I will illustrate the relevant dynamics and discuss implications for strongly gravitating horizonless systems.
The archive of previous seminars is here.
Note: In case one wishes to participate, please direct your queries to either Dr. Leo Stein <lcstein@olemiss.edu> or Dr. Anuradha Gupta <agupta1@olemiss.edu>.