Nonlinear interacting cosmological models after Planck 2018 legacy
  release and the $H_0$ tension
  Interacting dark energy models are widely renowned for giving an explanation
to the cosmic coincidence problem as well as several observational issues.
According to the recent observational data, and so far we are concerned with
the literature, the choice of the interaction function between dark matter and
dark energy is always questionable since there is no such underlying theory
that could derive it. Thus, in this work we have raised this issue by proposing
two new nonlinear interaction functions and constrain them using cosmic
microwave background (CMB) from Planck 2018, baryon acoustic oscillations
(BAO), dark energy survey and a measurement of the Hubble constant $H_0$ from
Hubble Space Telescope (HST) 2019. The dark energy equation of state is
considered to be constant throughout the work and the geometry of the universe
is assumed to be homogeneous and isotropic with zero spatial curvature. Our
analyses report that a non-zero interaction is always allowed by the
observational data and the dark energy equation of state is bent towards the
phantom regime. In particular, when $H_0$ from HST is added to Planck 2018+BAO,
we find an evidence for a non-zero coupling at more than $2\sigma$ confidence
level. Our analyses also report that for both the models, $H_0$ is close to its
local measurements and thus alleviating the $H_0$ tension. In particular, one
of the interacting models perfectly solves the $H_0$ tension.
