Title: Solitons and geometrical structures in a perfect fluid spacetime,
Abstract: Geometrical aspects of a perfect fluid spacetime are described in terms of
different curvature tensors and $\eta$-Ricci and $\eta$-Einstein solitons in a
perfect fluid spacetime are determined. Conditions for the Ricci soliton to be
steady, expanding or shrinking are also given. In a particular case when the
potential vector field $\xi$ of the soliton is of gradient type,
$\xi:=grad(f)$, we derive from the soliton equation a Laplacian equation
satisfied by $f$.