  In this proceeding we consider a massive charged scalar field in a uniform
electric field background in a de~Sitter spacetime (dS). We compute the
in-vacuum expectation value of the trace of the energy-momentum tensor for the
created Schwinger pairs, and using adiabatic subtraction scheme the trace is
regularized. The effect of the Schwinger pair creation on the evolution of the
Hubble constant is investigated. We find that the production of the
semiclassical pairs leads to a decay of the Hubble constant. Whereas, the
production of a light scalar field in the weak electric field regime leads to a
superacceleration phenomenon.
