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…
Photon Emission from Circular Equatorial Kerr Orbiters
Delilah E. A. Gates, Shahar Hadar, Alexandru Lupsasca
We consider monochromatic and isotropic photon emission from circular equatorial Kerr orbiters. We derive analytic expressions for the photon escape probability and the redshift-de…
Photon Ring Autocorrelations
Shahar Hadar, Michael D. Johnson, Alexandru Lupsasca +1
In the presence of a black hole, light sources connect to observers along multiple paths. As a result, observed brightness fluctuations must be correlated across different times an…
Maximum Observable Blueshift from Circular Equatorial Kerr Orbiters
Delilah E. A. Gates, Shahar Hadar, Alexandru Lupsasca
The region of spacetime near the event horizon of a black hole can be viewed as a deep potential well at large gravitational redshift relative to distant observers. However, matter…