A min-max theorem and its applications to nonconservative systems.
We describe a constructive method which yields two monotone sequences that converge uniformly to extremal solutions to the periodic boundary value problem u''(t) = f(t,u(t),u'(t)), u(0) = u(2π), u'(0) = u'(2π) in the presence of a lower solution α(t) and an upper solution β(t) with β(t) ≤ α(t).
We present a new approach to solving boundary value problems on noncompact intervals for second order differential equations in case of nonlocal conditions. Then we apply it to some problems in which an initial condition, an asymptotic condition and a global condition is present. The abstract method is based on the solvability of two auxiliary boundary value problems on compact and on noncompact intervals, and uses some continuity arguments and analysis in the phase space. As shown in the applications,...
We study the nonlinear boundary value problem involving reflection of the argument where and are continuous functions with . Using Galerkin approximations combined with the Brouwer’s fixed point theorem we obtain existence and uniqueness results. A numerical algorithm is also presented.
We study the nonexistence result of radial solutions to -Δu + c u/(|x|2) + |x|σ|u|qu ≤ 0 posed in B or in B {0} where B is the unit ball centered at the origin in RN, N ≥ 3. Moreover, we give a complete classification of radial solutions to the problem -Δu + c u/(|x|2) + |x|σ|u|qu = 0. In particular we prove that the latter has exactly one family of radial solutions.
In this paper, we develop a generalized quasilinearization technique for a nonlinear second order periodic boundary value problem and obtain a sequence of approximate solutions converging uniformly and quadratically to a solution of the problem. Then we improve the convergence of the sequence of approximate solutions by establishing the convergence of order