Constraining Dark Energy Sound Speed

Background: The influence of dark energy sound speed ($c_s^2$) on structure formation and cosmological constraints is a subject of theoretical interest in modified dark energy models.

Question / Future Work: Although allowing the dark energy sound speed ($c_s^2$) to vary freely did not significantly affect the constraints on other iDMDE parameters in the forecast, further investigation into the impact of varying $c_s^2$ across different future survey combinations and more non-linear scales might be warranted to fully explore its constraining potential.