Is the Effective Field Theory of Dark Energy Effective?

Understand

The effective field theory of cosmic acceleration systematizes possible contributions to the action, accounting for both dark energy and modifications of gravity.

• Rather than making model dependent assumptions, it includes all terms, subject to the required symmetries, with four (seven) functions of time for the coefficients.
• These correspond respectively to the Horndeski and general beyond Horndeski class of theories.
• We address the question of whether this general systematization is actually effective, i.e.