PIRSA:26030081

Probing spacetime with black hole mergers

Lu, N. (2026). Probing spacetime with black hole mergers. Perimeter Institute. https://pirsa.org/26030081

Lu, Neil. Probing spacetime with black hole mergers. Perimeter Institute, Mar. 26, 2026, https://pirsa.org/26030081 

          @misc{ pirsa_PIRSA:26030081,
            doi = {10.48660/26030081},
            url = {https://pirsa.org/26030081},
            author = {Lu, Neil},
            keywords = {Strong Gravity},
            language = {en},
            title = {Probing spacetime with black hole mergers},
            publisher = {Perimeter Institute},
            year = {2026},
            month = {mar},
            note = {PIRSA:26030081 see, \url{https://pirsa.org}}
          }

Neil Lu Australia National University

Talk numberPIRSA:26030081
DOI10.48660/26030081
Collection
Talk Type Scientific Series
Subject

Abstract

The detection of gravitational waves from binary black hole mergers enables us to observe the behavior of spacetimes in the strong-field, highly dynamical regime. The LIGO–Virgo–KAGRA collaboration has now observed hundreds of such events, offering several exciting candidates with differing properties. In this talk I will discuss recent results using these gravitational wave observations to test general relativity and probe the spacetime near black holes. I will present the first confident detection of an overtone in the ringdown signal during the postmerger phase of the binary black hole signal. I will also discuss the “direct wave” signal, a recently proposed model for the merger portion of the waveform that depends on the physics close to the black hole horizon. Finally, I will present the first results from applying this model to real data, using it to analyze the loudest gravitational wave event ever detected.