We consider the problem of multiplicity and uniqueness of radial solutions of a nonlinear elliptic equation of the form where f is a prescribed function, satisfying appropriate conditions. This paper is a review of recent ...

Using the notion of summable dichotomy in ordinary difference equations and the contraction and Schauder fixed point theorem, we obtain the existence of bounded and periodic solutions on ℤ under quite general hypotheses ...

After an aggregated problem has been solved, it is often desirable to estimate the accuracy loss due to the fact that a simpler problem than the original one has been solved. One way of measuring this loss in accuracy is ...

After an aggregated problem has been solved, it is often desirable to estimate the accuracy loss due to the fact that a simpler problem than the original one has been solved. One way of measuring this loss in accuracy is ...

Using a "summable" dichotomy and fixed-point theorems, we prove the existence of convergent and bounded solutions of nonlinear difference systems. © 1998 Elsevier Science Ltd. All rights reserved.

We establish the existence of bounded, almost periodic solutions and asymptotically almost periodic solutions for functional difference equations with infinite delay on abstract phase space. An application to Volterra ...

With a general mixing of vector and scalar couplings in a two-dimensional world, a short-range potential is used to explore certain features of the bound states of a spinless particle. Bound-state solutions are found in ...

We establish the uniqueness of the second radial bound state solution of