Coupling Metric-Affine Gravity to a Higgs-Like Scalar Field

Understand

General Relativity (GR) exists in different formulations.

• They are equivalent in pure gravity but generically lead to distinct predictions once matter is included.
• After a brief overview of various versions of GR, we focus on metric-affine gravity, which avoids any assumption about the vanishing of curvature, torsion or non-metricity.
• We use it to construct an action of a scalar field coupled non-minimally to gravity.