The 35th Midwest Relativity Meeting & Eric Fest

Session

Friday Morning Session 2

31 Oct 2025, 11:00

113 (MacKinnon Building)

3. Extracting Astrophysical Clues from Eccentric, Precessing Binary Black Hole Dynamics

Anuradha Gupta (The University of Mississippi)

31/10/2025, 11:00

The most general bound binary black hole (BBH) system has an eccentric orbit and precessing spins. Detecting a BBH with significant eccentricity near merger would be a clear signature of dynamical formation, while the spin–orbit misalignment angles (spin tilts) provide a powerful probe of different astrophysical formation channels. We have developed publicly available codes that evolve...

33. Geodesics and stability of a black hole surrounded by an anisotropic fluid

Diogo Gripa Rodrigues (NASA Goddard Space Flight Center)

31/10/2025, 11:15

The Kiselev metric has gained increasing relevance in recent years due to its ability to model a variety of physical systems. It describes a black hole influenced by the presence of an anisotropic fluid—composed of the superposition of a perfect fluid, an electromagnetic field, and a scalar field. Depending on the equation of state parameter $\omega$, this metric can model dispersed gases in...

6. Dynamical quasinormal mode excitation

Marina De Amicis (Niels Bohr Institute)

31/10/2025, 11:30

Current waveform models of binary black hole mergers incorporate a large amount of analytical information during the inspiral phase. On the other hand, post-merger templates use a phenomenological ansatz informed by numerical simulations, with the quasinormal frequencies as the only analytical input.
Working in the perturbative limit, we develop the first analytical model predicting the...

18. Perturbed black holes and Integrability

Carlos F. Sopuerta (Institute of Space Sciences of the Spanish National Research Council (ICE, CSIC))

31/10/2025, 11:45

Black Hole Perturbation Theory (BHPT) has been shown to be very successful in describing physical processes around BHs. In particular, the scattering of electromagnetic and gravitational waves (and other physical fields) and the so-called quasinormal mode (QNM) oscillations, the damped BH oscillations that dominate the ringdown phase of binary BH (BBH) coalescences.
A key feature of BHPT is...

20. Evolution of a black hole cluster in full general relativity

Jamie Bamber (University of Illinois Urbana-Champaign)

31/10/2025, 12:00

We evolve for the first time in full GR a small, collisional N-body black hole cluster of arbitrary total mass M. The bound cluster is initially compact (radius R/M≈10), stable, and consists of 25 equal-mass, nonspinning black holes. The dynamical interactions of compact objects in N-body clusters is of great interest for the formation of black holes in the upper mass gap as well as...

21. Influence of observer’s inclination and spacetime structure on photon ring observables

kiana salehi (perimeter Institute)

31/10/2025, 12:15

Recent millimeter-wavelength observations of the near-horizon regions of
M87 and Sgr A by the Event Horizon Telescope have significantly advanced our understanding of gravity and astrophysics under extreme conditions. A key goal for future observations, with improved angular resolution and sensitivity, is the detection of the photon ring in these black holes. For Kerr black holes, photon...