74 citations · 307 across the 11 of their papers we have counts for
8 papers · 1 filter
The bound on viscosity and the generalized second law of thermodynamics
Itzhak Fouxon, Gerold Betschart, Jacob D. Bekenstein
We describe a new paradox for ideal fluids. It arises in the accretion of an \textit{ideal} fluid onto a black hole, where, under suitable boundary conditions, the flow can violate…
Response to ``Comment on `Primordial magnetic seed field amplification by gravitational waves' "
G. Betschart, C. Zunkel, P. K. S. Dunsby +1
Here we respond to the comment by Tsagas (gr-qc/0503042) on our paper gr-qc/0503006. We show that the results in that comment are flawed and cannot be used for drawing conclusion a…
Perfect magnetohydrodynamics as a field theory
Jacob D. Bekenstein, Gerold Betschart
We propose the generally covariant action for the theory of a self-coupled complex scalar field and electromagnetism which by virtue of constraints is equivalent, in the regime of…
On inhomogeneous magnetic seed fields and gravitational waves within the MHD limit
Caroline Zunckel, Gerold Betschart, Peter K S Dunsby +1
In this paper we apply second-order gauge-invariant perturbation theory to investigate the possibility that the non-linear coupling between gravitational waves (GW) and a large sca…
Primordial magnetic seed field amplification by gravitational waves
Gerold Betschart, Caroline Zunckel, Peter Dunsby +1
Using second-order gauge-invariant perturbation theory, a self-consistent framework describing the non-linear coupling between gravitational waves and a large-scale homogeneous mag…
Scalar field and electromagnetic perturbations on Locally Rotationally Symmetric spacetimes
Gerold Betschart, Chris A. Clarkson
We study scalar field and electromagnetic perturbations on Locally Rotationally Symmetric (LRS) class II spacetimes, exploiting a recently developed covariant and gauge-invariant p…