374 citations · 1k across the 28 of their papers we have counts for
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Extreme Black Hole Anabasis
Shahar Hadar, Alexandru Lupsasca, Achilleas P. Porfyriadis
We study the transformation properties of spherically symmetric perturbations of the Bertotti-Robinson universe and identify an invariant that characterizes th…
Generalized Near Horizon Extreme Binary Black Hole Geometry
Jacob Ciafre, Shahar Hadar, Erin Rickenbach +1
We present a new vacuum solution of Einstein's equations describing the near horizon region of two neutral, extreme (zero-temperature), co-rotating, non-identical Kerr black holes.…
Near-extremal black holes at late times, backreacted
Shahar Hadar
Black holes display universal behavior near extremality. One such feature is the late-time blowup of derivatives of linearized perturbations across the horizon. For generic initial…
Is there a breakdown of effective field theory at the horizon of an extremal black hole?
Shahar Hadar, Harvey S. Reall
Linear perturbations of extremal black holes exhibit the Aretakis instability, in which higher derivatives of a scalar field grow polynomially with time along the event horizon. Th…
Whirling orbits around twirling black holes from conformal symmetry
Shahar Hadar, Achilleas P. Porfyriadis
Dynamics in the throat of rapidly rotating Kerr black holes is governed by an emergent near-horizon conformal symmetry. The throat contains unstable circular orbits at radii extend…
Fast plunges into Kerr black holes
Shahar Hadar, Achilleas P. Porfyriadis, Andrew Strominger
Most extreme-mass-ratio-inspirals of small compact objects into supermassive black holes end with a fast plunge from an eccentric last stable orbit. For rapidly rotating black hole…