arXiv subjects

Mehran Z-Abyaneh

Publications and source records attributed to Mehran Z-Abyaneh.

2 recordsLinked to original sources

arXiv2026

Gravitomagnetism from Temporal Dimensional Reduction

We reduce the Taub-NUT metric dimensionally to three spatial dimensions by treating time as an extra curled dimension, and end up with the 3-dimensional Einstein field equations plus a corresponding Maxwell type equations for a gravitomagnetic field, associated with the NUT charge, which also acts as a source for the Einstein field equations. In this approach, the Taub-NUT metric can be envisaged as a (1 + 3)-dimensional analogue of the (1 + 4)-dimensional metric of the Kaluza- Klein theory. Hence, in four dimensions, it unifies gravitation and gravitomagnetism, associated with the NUT charge, in the same footing that the Kaluza-Klein theory unifies gravitation and electromagnetism in five dimensions. In fact, in this way, gravity and gravitomagnetism, associated with the NUT charge, appear as two distinct fields that emerge from the temporal dimensional reduction. We also introduce a relation between the 4-dimensional gravitational constant and the NUT charge.

hep-th↗

arXiv2025

Symmetries of Weyl Superconductors with Different Pairings

We examine the Bogoliubov-de Gennes Hamiltonian and its symmetries for a time-reversal symmetry broken three dimensional Weyl superconductor. In the limit of vanishing pairing potential, we specify that this Hamiltonian is invariant under two sets of continues symmetries, i.e. the $U(1)$ gauge symmetry and the $U(1)_A$ axial symmetry. Although a pairing of the Bardeen-Cooper-Schrieffer type spontaneously breaks both of these symmetries, we show that a Fulde-Ferrell-Larkin-Ovchinnikov type pairing spontaneously breaks only the $U(1)$ gauge symmetry (that is then restored via the well-known scalar phase mode of superconductivity). Consequently, in the former case, two Nambu-Goldstone modes are required in the system to restore the broken symmetries. We indicate that one of these two modes is an emergent pseudo-scalar phase mode. We also demonstrate that such a phase mode leads to a pseudo-Meissner effect.

hep-th↗