Slowly Rotating Neutron Stars in Aether Scalar-Tensor Theory

TL;DR

This paper investigates slowly rotating neutron stars within Aether Scalar-Tensor theory, revealing unique I-C relations that could be tested through astrophysical observations, thus providing a potential way to distinguish this theory from general relativity.

Contribution

The authors derive and analyze neutron star solutions in Aether Scalar-Tensor theory, highlighting differences in I-C relations from general relativity and proposing observational tests.

Findings

Aether Scalar-Tensor theory predicts distinct I-C relations for neutron stars.

The theory successfully explains cosmological observations like CMB and matter power spectra.

Differences in neutron star properties offer potential tests for the theory.

Abstract

Aether Scalar-Tensor theory is a relativistic alternative gravity model that behaves like cold dark matter on cosmological scales while predicting the MOND force-law in astrophysical systems. The theory correctly predicts the cosmic microwave background and linear matter power spectra, and the mass discrepancies observed across the Universe. We derive and solve the equations governing neutron stars in Aether Scalar Tensor theory at first-order in slow rotation, finding that the theory predicts approximate universal relations between the moment of inertia and the compactness ($I$--$C$ relations) that differ from their general relativity counterparts. These relations may enable tests of Aether Scalar-Tensor theory using X-ray observations of pulsars and gravitational wave observations of binary neutron star mergers.