Adami R., Teta A.
A Simple Model of Concentrated Nonlinearity.
(18K, LATeX 2e)

ABSTRACT.  We study the nonlinear Schroedinger equation in dimension one
with a nonlinearity concentrated in a point. We give results on local
and global existence of the solution and find conditions for the blow-up.
In the critical case an explicit blow-up solution is constructed.