Hints of Early Dark Energy in Planck, SPT, and ACT data: new physics or systematics?

Tristan L. Smith, Matteo Lucca, Vivian Poulin +5

We investigate constraints on early dark energy (EDE) using ACT DR4, SPT-3G 2018, Planck polarization, and restricted Planck temperature data (at $\ell <650$), finding a $3.3\sigma$ pref…