Dr
Ignacy
Sawicki
CEICO, Institute of Physics of the Czech Academy of Sciences
I will review the existing tensions in cosmological observations as a motivation for a dynamical mechanism for accelerating the expansion of the universe alternative to a cosmological constant. I will discuss how the observation of gravitational waves has constrained the theory space for such ideas, but argue that possible dynamical models remain. I will discuss their phenomenology and how we expect to constrain them using upcoming cosmological data.