  We investigate the role of inhomogeneous field configurations in systems with
a spontaneously broken continuous global symmetry. Spontaneous breaking is
usually defined as a specific double limit, first infinite volume at finite
explicit breaking sources, which are then extrapolated to zero. We consider a
different approach in which the order parameter is constrained under the path
integral, which we simulate using lattice Monte Carlo techniques. In this way
we access the flat region of the effective potential and we show that
inhomogeneous configurations are dominant there. We topologically classify the
important configurations and measure the excess energy stored in the
inhomogeneities allowing for the definition of a generalized differential
surface tension. We show that this contribution becomes negligible at large
volumes restoring the flatness of the effective potential in the thermodynamic
limit.
