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We consider the perihelion precession and bending of light in a class of Kaluza-Klein models and show that the electric redshift model, proposed in Zhang (2006) to explain the redshift of Quasars, does not agree with observations. As Zhangs model only considers the Jordan frame, we also compute the perihelion precession as seen in the Einstein frame and show that, to lowest order, the perihelion precession can only be consistent with observation in the Einstein frame. However, when we consider the corresponding electric redshift in the Einstein frame, we find that the redshift is significantly lower than for the Jordan frame and is therefore very unlikely to explain the redshift of quasars.
We investigate the geodetic precession effect of a parallely transported spin-vector along a circular geodesic in the five-dimensional squashed Kaluza-Klein black hole spacetime. Then we derive the higher-dimensional correction of the precession angl
We studied spherically symmetric solutions in scalar-torsion gravity theories in which a scalar field is coupled to torsion with a derivative coupling. We obtained the general field equations from which we extracted a decoupled master equation, the s
The newly proposed island formula for entanglement entropy of Hawking radiation is applied to spherically symmetric 4-dimensional eternal Kaluza-Klein (KK) black holes (BHs). The charge $Q$ of a KK BH quantifies its deviation from a Schwarzschild BH.
We apply the Dirac-Bergmann algorithm for the analysis of constraints to gauge theories defined on spherically symmetric black hole backgrounds. We find that the constraints for a given theory are modified on such spacetimes through the presence of a
We discuss the Kaluza-Klein reduction of spaces with (anti-)self-dual Weyl tensor and point out the emergence of the Einstein-Weyl equations for the reduction from four to three dimensions. As a byproduct we get a simple expression for the gravitatio