Stellar Pulsations in Beyond Horndeski Gravity Theories
  Theories of gravity in the beyond Horndeski class recover the predictions of
general relativity in the solar system whilst admitting novel cosmologies,
including late-time de Sitter solutions in the absence of a cosmological
constant. Deviations from Newton's law are predicted inside astrophysical
bodies, which allow for falsifiable, smoking-gun tests of the theory. In this
work we study the pulsations of stars by deriving and solving the wave equation
governing linear adiabatic oscillations to find the modified period of
pulsation. Using both semi-analytic and numerical models, we perform a
preliminary survey of the stellar zoo in an attempt to identify the best
candidate objects for testing the theory. Brown dwarfs and Cepheid stars are
found to be particularly sensitive objects and we discuss the possibility of
using both to test the theory.
