Torsional oscillations in tensor-vector-scalar theory

TL;DR

This paper investigates torsional oscillations in relativistic stars within TeVeS theory, finding that their frequencies are higher than in GR and could help distinguish between the theories through astrophysical observations.

Contribution

It provides the first analysis of torsional oscillations in TeVeS theory, highlighting differences from GR that could be observed to test gravitational models.

Findings

Torsional frequencies in TeVeS are larger than in GR.

The frequency dependence on gravitational theory differs from that on the equation of state.

Potential to distinguish TeVeS from GR via stellar oscillation observations.

Abstract

With the Cowling approximation, the torsional oscillations on relativistic stars in tensor-vector-scalar (TeVeS) theory are examined. The spectrum features in TeVeS are very similar to those in general relativity (GR), but the torsional frequencies in TeVeS become larger than those expected in GR. We find that, compared with the fluid oscillations with polar parity, the torsional frequencies depend strongly on the gravitational theory. Since the dependences of fundamental frequencies on the gravitational theory and on the equation of state are different from those of overtone, it could be possible to distinguish TeVeS from GR in the strong-field regime via observations of this type of oscillations with the help of the observation of stellar mass.