2026 Fall Schedule

Abstract: Our Universe is still largely a mystery. Elusive dark matter shapes cosmic structures, while the Universe expands at a rate that we struggle to understand. Unraveling these fundamental open questions demands a deeper look into the distant cosmos, where gravitational waves from stellar-mass binary black holes offer a unique observational window. 

Unlike electromagnetic signals, gravitational waves traverse the Universe without alteration, except for gravitational lensing. Their long wavelengths make them subject to diffraction by cosmic structures, providing an unprecedented opportunity to map dark matter and test the foundations of gravity. If we can recover these lensed signals, we gain a cosmic magnifying glass to observe the most distant black hole mergers and illuminate their origins. Current gravitational-wave observations have already produced puzzling lensing candidates (e.g., GW231123), and the first definitive detections are expected very soon.

In this talk, I will explain why gravitational-wave lensing is uniquely informative, outline how deep‑learning methods can accelerate its discovery, and show what the first detections could reveal about dark‑matter substructure and astrophysical black hole formation channels.

Abstract: TBA

Abstract: TBA

Abstract: TBA

Abstract: Accreting supermassive black holes are known to be variable, changing in brightness across all wavelengths and timescales. In recent years, a remarkable subset of these Active Galactic Nuclei (AGN) has been discovered to show extreme spectral variability. These changing-look events are thought to arise from extreme and rapid changes in how fast the black hole is feeding, defying the expected accretion timescales for black holes with masses of millions to billions of solar masses. Such rapid variations provide unique insights into the physics of accretion in supermassive black holes.With the upcoming Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST), we expect to uncover thousands of these dramatic transformations, thanks to its combination of depth and rapid, repeated imaging of the sky. In this talk, I will review what we have learned about changing-look AGN so far, and look ahead to how LSST, combined with new large-scale spectroscopic surveys such as 4MOST, will open a new era in our understanding of black hole accretion physics.