Weak Gravity Limit in Newer General Relativity

TL;DR

This paper investigates linearised equations in Newer General Relativity models, revealing additional dynamical modes and fixing model parameters based on tensor and vector properties, thus advancing understanding of these theories.

Contribution

It demonstrates that STEGR with a gradient squared of the metric determinant has three halves more dynamical modes than previously thought, and clarifies parameter fixing in Newer GR models.

Findings

STEGR with gradient squared of the metric determinant has three halves more dynamical modes.

Half of the model parameter freedom is fixed by tensor and vector properties.

The analysis reveals more complex scalar sector behavior in Newer GR.

Abstract

We analyse linearised field equations around the Minkowski metric with its standard flat parallel transport in models of Newer GR, that is quadratic actions in terms of nonmetricity tensor. We show that half of the freedom in choosing the model parameters is immediately fixed by asking for reasonable properties of tensors and vectors, defined with respect to spatial rotations, and accurately describe the much more complicated sector of scalars. In particular, we show that, from the teleparallel viewpoint, the model of STEGR with addition of a gradient squared of the metric determinant exhibits three halves new dynamical modes, and not just one like it was previously claimed.