Constraints on fourth order gravity from binary pulsar and gravitational waves

TL;DR

This paper tests a fourth order gravity model against binary pulsar and gravitational wave data, finding it consistent if the model's length parameter is below a certain upper limit.

Contribution

It provides observational constraints on a fourth order gravity model using binary pulsar data and gravitational wave emission, linking theory with astrophysical measurements.

Findings

Model is consistent with binary pulsar observations

Length parameter must be below a certain upper bound

Supports viability of the fourth order gravity model

Abstract

We have earlier proposed a fourth order gravity model as a possible explanation for late time cosmic acceleration, and for flattened galaxy rotation curves. The model has a free length parameter whose value depends on the scale of the system under study (e.g. the whole Universe, a galaxy, or a compact binary pulsar). In the present work, we investigate the constraints imposed on the free model parameter by Hulse-Taylor binary pulsar data: periastron advance; and emission of gravitational waves and consequent period decay. It is shown that the model is consistent with these observations, provided the length parameter is bounded from above.