Using elementary arguments, we shall show that every bounded disjointness preserving linear functional of the Wiener ring L1 (Z) assumes the form (f)=

For Banach lattices X and Y, let X | | Y and X | | Y denote the positive projective and injective tensor products of X and Y, respectively. In this paper, we characterize the inheritance of reflexivity and containment of copies of c 0, 1, by X | | Y and X | | Y from X and Y, when one of them is an atomic Banach lattice. In this case, we also give an affirmative answer to an open question of Jeurnink.

Assume that <i>F</i> is a nonlinear operator on a real Hilbert space <i>H</i> which is -strongly monotone and -Lipschitzian on a nonempty closed convex subset <i>C</i> of <i>H</i>. Assume also that <i>C</i> is the intersection of the fixed-point sets of a finite number of nonexpansive mappings on <i>H</i>. We construct an iterative algorithm with variable parameters which generates a sequence {<i>x</i> _<i>n</i>} from an arbitrary initial point <i>x</i> ₀ <i>H</i>. The sequence {<i>x</i> _<i>n</i>} is shown to converge in norm to the unique solution <i>u</i>  of the variational inequality

We look for bounded periodic solutions for a parametric fractional problem involving a continuous nonlinearity with subcritical growth. By using a variant of Caffarelli and Silvestre extension method adapted to the periodic case and variational tools we prove the existence of at least three bounded periodic solutions when the parameter varies in an appropriate range.

In this paper, we introduce a broad class of nonlinear mappings in a Hilbert space which covers nonexpansive mappings, nonspreading mappings, hybrid mappings and contractive mappings. Then we prove fixed point theorems for the class of such mappings. Using these results, we prove well-known and new fixed point theorems in a Hilbert space.