  We have studied the emergence of bound states in weakly deformed and/or
heterogeneous waveguides, comparing the analytical predictions obtained using a
recently developed perturbative method, with precise numerical results, for
different configurations (a homogeneous asymmetric waveguide, a heterogenous
asymmetric waveguide and a homogeneous broken-strip). In all the examples
considered in this paper we have found excellent agreement between analytical
and numerical results, thus providing a numerical verification of the
analytical approach.
