374 citations · 2.5k across the 52 of their papers we have counts for
7 papers · 1 filter
Generalized Couch--Torrence inversions
Panagiotis Charalambous, Laura Donnay, Alexandru Lupsasca
The Laplace equation on Euclidean flat space admits a discrete radial inversion symmetry. In 1983, Couch and Torrence (CT) found -- surprisingly -- that the massless wave equation…
Early science acceleration experiments with GPT-5
Sébastien Bubeck, Christian Coester, Ronen Eldan +11
AI models like GPT-5 are an increasingly valuable tool for scientists, but many remain unaware of the capabilities of frontier AI. We present a collection of short case studies in…
Gravitational Waves on Kerr Black Holes II: Metric Reconstruction with Cosmological Constant
Roman Berens, Trevor Gravely, Alexandru Lupsasca
In this second paper of our series started with \cite{Berens2024}, we investigate linearized gravitational perturbations of a rotating Kerr black hole in a non-asymptotically flat…
Interferometric inference of black hole spin from photon ring size and brightness
Joseph R. Farah, Alexandru Lupsasca, Eliot Quataert +1
The photon ring is a full image of the astrophysical source around a black hole, produced by photons that execute half-orbit around the event horizon on their way…
Black Hole Polarimetry II: The Connection Between Spin and Polarization
George N. Wong, Andrew Chael, Alexandru Lupsasca +1
We study synchrotron polarization in spatially resolved horizon-scale images, such as those produced by the Event Horizon Telescope (EHT). In both general relativistic magnetohydro…
Photon rings in a holographic toy model
Stéphane Detournay, Sahaja Kanuri, Alexandru Lupsasca +3
Light circling around an astrophysical black hole can spend a long time skirting its unstably bound photon orbits before escaping to infinity. To a distant observer, this orbiting…
Why there is no Love in black holes
Alexandru Lupsasca
This paper presents a new conformal symmetry of stationary, axisymmetric Kerr perturbations. This symmetry is exact but non-geometric (or "hidden"), and each of its generators has…