Bumblebee black holes in light of Event Horizon Telescope observations

TL;DR

This paper introduces new static black-hole solutions in a vector-tensor gravity model and tests their compatibility with recent Event Horizon Telescope observations, finding most parameter ranges remain viable.

Contribution

It presents novel black-hole solutions in bumblebee gravity and performs the first strong-field tests using EHT data.

Findings

Parameter space largely unexcluded by current observations

More experiments needed to constrain the theory

Black-hole shadows consistent with some bumblebee gravity solutions

Abstract

We report the existence of novel static spherical black-hole solutions in a vector-tensor gravitational theory called the bumblebee gravity model which extends the Einstein-Maxwell theory by allowing the vector to nonminimally couple to the Ricci curvature tensor. A test of the solutions in the strong-field regime is performed for the first time using the recent observations of the supermassive black-hole shadows in the galaxy M87 and the Milky Way from the Event Horizon Telescope Collaboration. The parameter space is found largely unexcluded and more experiments are needed to fully bound the theory.