Exner P.
A duality between Schroedinger operators on graphs and certain
Jacobi matrices   
(32K, LATEX)

ABSTRACT.  The known correspondence between the Kronig-Penney 
model and certain Jacobi matrices is extended to a wide class of 
Schroedinger operators on graphs. Examples include rectangular 
lattices with and without a magnetic field, or comb-shaped graphs 
leading to a Maryland-type model.