Resumo:
In this text we study the Einstein equations in the spatially flat spacetimes (Bianchi-I)
which are endowed with an extra locally rotational symmetry (LRS). We develop a new
local coordinate representation where we use the components of the energy-momentum
tensor directly in the metric, the energy density being the "time" coordinate. As an
application, some general classes of exact solutions are obtained which are of physical and
mathematical interest. In particular, the general barotropic perfect fluid solution is given,
p = p( ).
