Instabilities of Scalar Fields around Oscillating Stars

The behavior of fundamental fields in strong gravity or nontrivial environments is important for our understanding of nature. This problem has interesting applications in the context of dark matter, of dark energy physics, or of quantum field theory. The dynamics of fundamental fields has been studied mainly in static or stationary backgrounds, whereas most of our Universe is dynamic. In this Letter we investigate blueshift and parametric instabilities of scalar fields in dynamical backgrounds, which can be triggered (for instance) by oscillating stars in scalar-tensor theories of gravity. We discuss possible implications of our results, which include constraints on an otherwise hard-to-access parameter space of scalar-tensor theories.

Automated summary

The behavior of fundamental fields in strong gravity or nontrivial environments plays a vital role in understanding nature. In this study, the dynamics of scalar fields in dynamic backgrounds were investigated, revealing implications for constraining the parameter space of scalar-tensor theories. The study sheds light on the significance of studying fundamental fields in dynamic environments.