Gravitational Lensing by Black Holes in Einstein Quartic Gravity

TL;DR

This paper explores how Einstein Quartic Gravity predicts different gravitational lensing effects by black holes compared to general relativity, with potential observable deviations in image positions and time delays.

Contribution

It provides an approximate analytic solution for black holes in EQG and compares lensing predictions with GR, highlighting observable differences.

Findings

Deviations in image positions up to milliarcseconds from GR

Time delays can differ significantly from GR predictions

Potential for observational tests of EQG in the near future

Abstract

We investigate gravitational lensing effects of spherically symmetric black holes in Einstein Quartic Gravity (EQG). Using an approximate analytic solution obtained by continued fraction methods we consider the predictions of EQG for lensing effects by supermassive black holes at the center of our galaxy and others in comparison with general relativity (GR). We numerically compute both time delays and angular positions of images and find that they can deviate from GR by as much as milliarcseconds, suggesting that observational tests of EQG are feasible in the near future. We discuss the challenges of distinguishing the predictions of EQG from those of Einstein Cubic Gravity.