Department of Mathematics,

University of Patras,

Rio 26500,

GREECE

E-mail: spawn@math.upatras.gr, tsoubeli@math.upatras.gr

_{Symmetry Analysis of Boussinesq Type Systems and
Complete Invariance of Associated Initial and Boundary Value Problems}

**Abstract:**

The classical and conditional symmetries of two Boussinesq type systems,
namely of the so-called KdV-KdV and the Classical Boussinesq system, are
determined. These symmetries and the notion of complete invariance are
used in deriving exact solutions of initial-boundary value problems
for the above systems of nonlinear evolution equations.