Mathematics, Department of


Date of this Version



Published in Transactions of the American Mathematical Society, Vol. 104, No. 3. (Sep., 1962), pp. 392-397.


Copyright © 1962 American Mathematical Society. Used by permission.


The classical Liouville Theorem of analytic function theory can be stated in either of two equivalent forms: The Liouville Theorem states: If f(w) is analytic and bounded throughout the finite w-plane, then f(w) is constant. If z(x, y) is a real valued function of the real variables x and y which is a solution of zxx + zyy = 0 and is bounded either above or below throughout the finite plane, then z(x, y) is a constant. Here we are concerned with the question of whether or not the second formulation of the above theorem is valid for solutions of more general elliptic partial differential equations.