Gravity Workshop: Mergers and Beyond
April 15–16, 2026 - University of Tübingen (room C10 L08)
Program
Day 1: Wednesday April 15
09:45 – 10:00: Prof. Kostas Kokkotas, University of Tübingen, Germany
Welcome
10:00 – 10:45: Prof. Andrea Maselli, Gran Sasso Science Institute (GSSI), Italy
“Challenging the vacuum binary paradigm with gravitational wave observations“
Abstract: Astrophysical environments offer a natural setting to test the standard vacuum description of compact binary coalescences with gravitational waves. In this talk, I discuss what binary black hole observations can realistically probe beyond the vacuum paradigm, emphasizing both opportunities and fundamental limitations. I examine how surrounding matter or fields modify orbital dynamics and waveform phasing, and identify which signatures are degenerate with intrinsic binary parameters or with higher-order vacuum effects. I then assess the impact of these degeneracies on parameter inference, highlighting the observables that remain robust and the associated systematic uncertainties. Finally, I outline the regimes in which current and next-generation detectors can meaningfully constrain environmental effects, as well as those where such tests remain intrinsically challenging.
10:45 - 11:30
Coffee Break
11:30 – 12:15: Dr. Sebastian Völkel, University of Tübingen, Germany
“Black hole spectroscopy: Are we ready for what lies ahead?”
Abstract: The first direct detection of gravitational waves from two merging black holes occurred more than a decade ago. Since then, gravitational-wave astronomy has revolutionized our ability to study black holes and neutron stars and to test Einstein’s theory of general relativity. Gravitational waves are now an essential tool for astronomers, and future detectors promise unprecedented opportunities to explore the dark universe. Black hole spectroscopy, in particular, is key for probing fundamental physics and the nature of compact objects. In this talk, I will briefly review the current status of gravitational-wave astronomy before focusing on recent progress and open challenges in black hole spectroscopy. Looking ahead to the next generation of ground- and space-based detectors, a central question emerges: Are we ready for what lies ahead? Are our theoretical models sufficiently accurate to fully realize the scientific potential of these instruments, or will systematic biases limit our discoveries?
12:15 – 14:00
Lunch break
14:00 – 14:45: PhDc. Davide Perrone, University of Geneva, Switzerland
“Dynamical Love numbers from a shell effective field theory”
Abstract: I will discuss how to construct a novel effective field theory for a compact body coupled to gravity, whose key feature is that the dynamics of the gravitational perturbations is explicitly determined by known solutions in black hole perturbation theory in 4d. In this way the physical effects of gravitational perturbation in curved space are already encoded in the effective field theory, bypassing the need for the higher-order calculation that constitute an hurdle in standard approaches. I will show how to model a compact body as a shell, whose finite size regulates short distance divergencies in 4d and whose tidal responses are described by higher dimensional operators.
14:45 – 15:30: Q&A - Discussion
Day 2: Thursday April 16
10:00 – 10:45: Prof. Pantelis Pnigouras, University of Alicante, Spain
“Asteroseismology with binary neutron stars”
Abstract: During the late stages of a neutron star binary inspiral finite-size effects come into play, with the tidal deformability of the supranuclear density matter leaving an imprint on the gravitational-wave signal. As demonstrated in the case of GW170817—the first direct detection of gravitational waves from a neutron star binary—this can lead to constraints on the neutron star equation of state. As detectors become more sensitive, the hydrostatic response of the neutron star to the tidal field of its companion (equilibrium tide) needs to be supplemented by dynamical effects, such as oscillation mode resonances triggered by the orbital motion (dynamical tide). In this talk, we will demonstrate how dynamical tidal effects can serve as a tool for asteroseismology studies, in order to extract information about the neutron star internal structure. In addition, we will discuss a recently-discovered gravitational-wave-driven tidal secular instability in neutron star binaries, in which gravitational-wave emission may pump energy into the tide, thus slowing down the inspiral and affecting the gravitational-wave phasing. These studies are highly relevant for the future of gravitational-wave observations, since the effects of tides on the gravitational-wave signal are among the scientific goals of next-generation gravitational-wave detectors, like the Einstein Telescope.
10:45 - 11:30
Coffee Break
11:30 – 12:15: Prof. Kostas Kokkotas, University of Tübingen, Germany
“Some new results on neutron star dynamics”
Abstract: TBA
12:00 – 13:30
Lunch break
14:00 – 14:45: Q&A - Discussion
Organizing Committee
- Dr. Arthur Suvorov
- Marta Piscitelli
- Kostas Kourmpetis