27 citations · 94 across the 14 of their papers we have counts for
15 papers
A theory agnostic uniqueness theorem for the Kerr solution
Joshua Baines
In this paper, we show that under a suitable set of symmetry arguments and asymptotic conditions, the uniqueness of the Kerr solution can be proven. None of the conditions consider…
Exact analytic photon escape cones and silhouettes for extremal Kerr
Joshua Baines, Matt Visser
We exhibit exact analytic, fully explicit, photon escape cones and related silhouettes ("shadows") at arbitrary distance from the extremal Kerr black hole. In contrast to the situa…
Perturbative photon escape cones in the Kerr spacetime
Joshua Baines, Matt Visser
We consider the perturbative, fully explicit, analytical behaviour of photon escape cones in the Kerr spacetime. When one conducts the fully general non-perturbative Kerr analysis,…
Photon escape cones, physical and optical metrics, asymptotic and near-horizon physics
Joshua Baines, Matt Visser
We consider the explicit analytic behaviour of photon escape cones in generic static spherically symmetric spacetimes, emphasizing the interplay between the physical spacetime metr…
Defect wormholes are defective
Joshua Baines, Rudeep Gaur, Matt Visser
The various "defect wormholes" developed by Klinkhamer have recently attracted considerable attention -- especially in view of the fact that the simplest example, the so-called "va…
Explicit formulae for surface gravities in stationary circular axi-symmetric spacetimes
Joshua Baines, Matt Visser
Using minimalist assumptions we develop a natural functional decomposition for the spacetime metric, and explicit tractable formulae for the surface gravities, in arbitrary station…
Killing horizons and surface gravities for a well-behaved three-function generalisation of the Kerr spacetime
Joshua Baines, Matt Visser
Thanks to the recent advent of the event horizon telescope (EHT), we now have the opportunity to test the physical ramifications of the strong-field near-horizon regime for astroph…
Physically motivated ansatz for the Kerr spacetime
Joshua Baines, Matt Visser
Despite some 60 years of work on the subject of the Kerr rotating black hole there is as yet no widely accepted physically based and pedagogically viable ansatz suitable for derivi…
Constant- geodesics in the Painleve-Gullstrand form of Lense-Thirring spacetime
Joshua Baines, Thomas Berry, Alex Simpson +1
Herein we explore the non-equatorial constant- ("quasi-circular") geodesics (both timelike and null) in the Painleve-Gullstrand variant of the Lense-Thirring spacetime recently…
Geodesics for the Painleve-Gullstrand form of Lense-Thirring spacetime
Joshua Baines, Thomas Berry, Alex Simpson +1
Recently, the current authors have formulated and extensively explored a rather novel Painleve-Gullstrand variant of the slow-rotation Lense-Thirring spacetime, a variant which has…
Killing tensor and Carter constant for Painleve-Gullstrand form of Lense-Thirring spacetime
Joshua Baines, Thomas Berry, Alex Simpson +1
Recently, the authors have formulated and explored a novel Painleve-Gullstrand variant of the Lense-Thirring spacetime, which has some particularly elegant features -- including un…
Unit-Lapse Forms of Various Spacetimes
Joshua Baines
Every spacetime is defined by its metric, the mathematical object which further defines the spacetime curvature. From the relativity principle, we have the freedom to choose which…
Darboux diagonalization of the spatial 3-metric in Kerr spacetime
Joshua Baines, Thomas Berry, Alex Simpson +1
The astrophysical importance of the Kerr spacetime cannot be overstated. Of the currently known exact solutions to the Einstein field equations, the Kerr spacetime stands out in te…
Unit-lapse versions of the Kerr spacetime
Joshua Baines, Thomas Berry, Alex Simpson +1
The Kerr spacetime is perhaps the most astrophysically important of the currently known exact solutions to the Einstein field equations. Whenever spacetimes can be put in unit-laps…
Painleve-Gullstrand form of the Lense-Thirring spacetime
Joshua Baines, Thomas Berry, Alex Simpson +1
The standard Lense-Thirring metric is a century-old slow-rotation large-distance approximation to the gravitational field outside a rotating massive body, depending only on the tot…