Necessary and sufficient conditions for the local solvability in hyperfunctions of a class of systems of complex vector fields.
We discuss the existence of solutions and Ulam's type stability concepts for a class of partial functional fractional differential inclusions with noninstantaneous impulses and a nonconvex valued right hand side in Banach spaces. An example is provided to illustrate our results.
A new method to solve stationary one-dimensional Schroedinger equation is investigated. Solutions are described by means of representation of circles with multiple winding number. The results are demonstrated using the well-known analytical solutions of the Schroedinger equation.
A new variational principle and duality for the problem Lu = ∇G(u) are provided, where L is a positive definite and selfadjoint operator and ∇G is a continuous gradient mapping such that G satisfies superquadratic growth conditions. The results obtained may be applied to Dirichlet problems for both ordinary and partial differential equations.
Dans ce travail, nous avons montré que si , où les sont des champs de vecteurs linéairement independants dans un ouvert de tels que l’algèbre de Lie qu’ils engendrent soit de rang maximum en tout point et la forme volume qu’on leur associe soit de classe 4 en un point de , alors il existe un voisinage ouvert de et une fonction tels que possède pas la propriété de prolongement unique.
It is proved that the solution to the initial value problem , u(0,x) = 1/(1+x²), does not belong to the Gevrey class in time for 0 ≤ s < 1. The proof is based on an estimation of a double sum of products of binomial coefficients.
The paper deals with error estimates and lower bound approximations of the Steklov eigenvalue problems on convex or concave domains by nonconforming finite element methods. We consider four types of nonconforming finite elements: Crouzeix-Raviart, , and enriched Crouzeix-Raviart. We first derive error estimates for the nonconforming finite element approximations of the Steklov eigenvalue problem and then give the analysis of lower bound approximations. Some numerical results are presented to...
We discuss the solvability of a nonhomogeneous boundary value problem for the semilinear equation of the vibrating string in a bounded domain and with a certain type of superlinear nonlinearity. To this end we derive a new dual variational method.
The paper surveys recent results obtained for the existence and multiplicity of radial solutions of Dirichlet problems of the type where is the open ball of center and radius in , and is continuous. Comparison is made with similar results for the Laplacian. Topological and variational methods are used and the case of positive solutions is emphasized. The paper ends with the case of a general domain.
We study the lifespan of solutions to fully nonlinear second-order Cauchy problems with small real- or complex-analytic data. The nonlinear term is an analytic function in u, ū and their derivatives. We give an outline of the proof based on the method of majorants and the fixed point technique.
The nonlinear dissipative wave equation in dimension has strong solutions with the following structure. In the solutions have a focusing wave of singularity on the incoming light cone . In that is after the focusing time, they are smoother than they were in . The examples are radial and piecewise smooth in