On the multipole moments of a rigidly rotating fluid body

TL;DR

This paper presents a new conjecture about the multipole moments of a rigidly rotating fluid body, suggesting its exterior cannot be described by the Kerr metric, based on numerical and analytical methods.

Contribution

It introduces a novel conjecture linking multipole moments to the exterior spacetime of rotating fluid bodies, challenging the Kerr metric description.

Findings

Conjecture that the exterior of a rotating fluid body differs from Kerr metric.

Numerical and analytical evidence supporting the conjecture.

Implication that rotating fluid bodies have unique exterior geometries.

Abstract

Based on numerical simulations and analytical calculations we formulate a new conjecture concerning the multipole moments of a rigidly rotating fluid body in equilibrium. The conjecture implies that the exterior region of such a fluid is not described by the Kerr metric.