Frame-dragging Effect in Strong Gravity Regime

TL;DR

This paper derives exact frame-dragging rates for various spacetimes, revealing anomalies and potential astrophysical signatures of NUT charge, with implications for understanding pulsar interiors and strong gravity effects.

Contribution

It provides the first exact calculations of frame-dragging in Kerr, Kerr-Taub-NUT, and Taub-NUT spacetimes, highlighting anomalies and their astrophysical significance.

Findings

Exact frame-dragging rates derived for Kerr, KTN, and Taub-NUT spacetimes.

Anomalous LT precession observed in pulsar interiors and KTN spacetime.

Potential observational signatures of NUT charge in pulsars.

Abstract

The exact frame-dragging (or Lense-Thirring (LT) precession) rates for Kerr, Kerr-Taub-NUT (KTN) and Taub-NUT spacetimes have been derived. Remarkably, in the case of the `zero angular momentum' Taub-NUT spacetime, the frame-dragging effect is shown not to vanish, when considered for spinning test gyroscope. In the case of the interior of the pulsars, the exact frame-dragging rate monotonically decreases from the center to the surface along the pole and but it shows an `anomaly' along the equator. Moving from the equator to the pole, it is observed that this `anomaly' disappears after crossing a critical angle. The `same' anomaly can also be found in the KTN spacetime. The resemblance of the anomalous LT precessions in the KTN spacetimes and the spacetime of the pulsars could be used to identify a role of Taub-NUT solutions in the astrophysical observations or equivalently, a signature of the existence of NUT charge in the pulsars.