Holographic Ricci DE as running vacuum with nonlinear interactions
  The holographic Ricci dark energy can be treated as a running vacuum due to
its analogy in the energy density, which is a combination of $H$ and $\dot H$,
the model can predict either eternal acceleration or eternal deceleration. In
the earlier works, we have shown that the presence of additive constant in the
energy density or by considering possible interaction between dark sectors
through a phenomenological term, the model can predict a transition from a
prior decelerated to a late accelerated epoch. This paper analyses the cosmic
evolution of holographic Ricci dark energy as a running vacuum with a nonlinear
interaction between dark sectors in a flat FLRW universe. We consider three
possible nonlinear interaction forms which give analytically feasible
solutions. We have constrained the model using the Type1a
Supernova(Pantheon)+CMB(Planck 2018)+BAO(SDSS) data and evaluated the
best-estimated values of all the model parameters. We have analyzed the
evolution of the Hubble parameter and deceleration parameter of all three
cases. We perform state finder analysis of the model, which implies the
quintessence nature of the model and found that it is distinguishably different
from the standard $\Lambda$CDM model. The dynamical system analysis of all
three cases confirms the evolution of the universe from an unstable prior
matter-dominated era to a stable end de Sitter phase.
