Dark Energy as a Critical Phenomenon: a Resolution for Hubble Tension
  We propose a dark energy model based on the physics of critical phenomena
which is consistent with both the Planck's CMB and the Riess et al.'s local
Hubble measurements. In this model the dark energy density behaves like the
magnetization of the Ising model. This means the dark energy is an emergent
phenomenon and we named it critically emergent dark energy model, CEDE. In
CEDE, dark energy emerges at a transition redshift, $z_c$, corresponding to the
critical temperature in critical phenomena. Combining the Planck CMB data and
local measurement of the Hubble constant from Riess et al. (2019) we find
statistically significant support for this transition with respect to the case
of very early transition that represents effectively the cosmological constant.
This is understandable since CEDE model naturally prefers larger values of
Hubble constant consistent with local measurements. Since CEDE prefers a
non-trivial transition when we consider both high redshift Planck CMB data and
local Hubble constant measurements, we conclude that $H_0$ tension can be a
hint for the substructure of the dark energy as a well-studied properties of
critical phenomena.
