  Whightman function, vacuum expectation values of the field square, and the
energy-momentum tensor are investigated for a scalar field inside a wedge with
and without a coaxial cylindrical boundary. Dirichlet boundary conditions are
assumed on the bounding surfaces. The vacuum energy-momentum tensor is
evaluated in the general case of the curvature coupling parameter. Making use
of a variant of the generalized Abel-Plana formula, expectation values are
presented as the sum of two terms. The first one corresponds to the geometry
without a cylindrical boundary and the second one is induced by the presence of
this boundary. The asymptotic behaviour of the field square, vacuum energy
density and stresses near the boundaries are investigated. The additional
vacuum forces acting on the wedge sides due the presence of the cylindrical
boundary are evaluated and it is shown that these forces are attractive. As a
limiting case, the geometry of two parallel plates perpendicularly intersected
by a third one is analyzed.
