Family of scalar-nonmetricity theories of gravity

Understand

We extend the class of recently formulated scalar-nonmetricity theories by coupling a five-parameter nonmetricity scalar to a scalar field and considering a mixed kinetic term between the metric and the scalar field.

• The symmetric teleparallel constraint is invoked by Lagrange multipliers or by inertial variation.
• The equivalents for the general relativity and ordinary (curvature-based) scalar-tensor theories are obtained as particular cases.
• We derive the field equations, discuss some technical details, e.g., debraiding, and formulate the Hamilton-like approach.