Quadratic theory of gravity with a scalar field and type I Shapovalov wave spacetimes

TL;DR

This paper derives exact gravitational-wave solutions in a quadratic gravity theory with a scalar field within Shapovalov type I spacetimes, offering new models not present in general relativity, useful for testing alternative gravity theories.

Contribution

It provides the first exact solutions for gravitational waves in quadratic gravity with a scalar field in Shapovalov type I spacetimes, expanding the understanding of such models.

Findings

Exact solutions for gravitational waves in quadratic gravity with scalar field.

Shapovalov type I spacetimes depend on three variables, including the wave variable.

Models can test the realism of alternative gravity theories.

Abstract

For the quadratic theory of gravity with a scalar field, exact solutions are found for gravitational-wave models in Shapovalov~I~type spacetimes, which do not arise in models of the general theory of relativity. The theory of gravity under consideration can effectively describe the early stages of the dynamics of the universe. Type I Shapovalov spaces are the most general form of gravitational-wave Shapovalov spacetimes, whose metric in privileged coordinate systems depends on three variables, including the wave variable. For Einstein vacuum spacetimes, these wave models degenerate into simpler types. The obtained exact models of gravitational waves in the quadratic theory of gravity can be used to test the realism of such theories of gravity.