Existence results are established for the equation y '' +f(t, y) = 0, 0 < t < 1. Here f may be singular in y and f is allowed to change sign. Our boundary data include y(0) = y'(1) + ky(1) = 0, k > -1 and y(0) = ...

We prove the existence of nonnegative solutions of the problem (py')'/p + mu qg(x, y) = 0, lim(x-->0+)py' = 0, h(y'(1)) + y(1) = 0 for a physically motivated class of nonlinearity h. The results, which are established ...

Fixed point theory is presented for compact u.s.c. and l.s.c. set valued maps.

We study the existence and multiplicity of solutions for the three-point nonlinear boundary value problem u '' ( t) +lambda a(t) f (u) = 0, 0 < t < 1; u( 0) = 0 = u(1)-gamma u(eta), where eta is an element of (0,1), ...

The Schauder Tychonoff theorem in a locally convex topological space is used to establish existence results for Volterra-Hammmerstein and Hammerstein integral equations in a reflexive Banach space.