1,720,988 research outputs found
Absence of global solutions to systems of perturbed parabolic inequalities with Chipot-Weissler nonlinearity in the gradient term
No full textFor a wide class of systems of nonlinear parabolic inequalities with Chipot- Weissler nonlinearity in the gradient term which depend on two nonnegative parameters λ1 and λ2, we study the nonexistence of global solutions according to the "test function" method. We establish theorems that, when λ1 = λ2 = 0, include and, in some cases, improve, or, in part, yield the results obtained by Escobedo and Herrero; Escobedo and Levine; Galaktionov;Levine, Lieberman and Meier; Mitidieri and Pohozaev; Pohozaev and Tesei
Existence theorems for a general variational equation with non coercive main part
No full textBy using the fibering method, we study the solvability of a general variational equation with non coercive main part in a real and reflexive Banach space. The results we get in this paper are useful for searching weak solutions of many problems connected to nonlinear differential homogeneous equations
A new approach for the existence of time periodic solutions of special classes of nonlinear problems
No full textWe study the existence of one or more weak periodic solutions of nonlinear evolution PDEs in a cylinder of RN+1 with conditions on lateral surface by using the results connected to a general evolution variational equation depending on a parameter. To this aim we state existence theorems and in some particular cases we give sufficient conditions about the nonstationarity of the found solutions. In these nonlinear evolution PDEs second partial derivatives with respect to time are also present
On weak extensions of extreme problems for nonlinear operator equations (Part I: Weak Solutions)
No full textIn the paper weak extensions of extreme problems for objects, which are described by nonlinear operator equations with the operators being densely defined and, strictly speaking, not maximal, are investigated. Theorems of the existence of strong and weak solutions are proved. Examples of classes of maps are given
Nonlinear differential-operator equations in Banach Space with mappings of a pseudomonotonic type (Part I. Conditions of Solvability)
No full textOn optimal control of singular mixed systems
No full textAnalysis of optimal control problems for objects, whose mathematical model is described by equations of different types (with partial derivatives, ordinary differential equations, integral equations etc.) Conditions of solvability and properties of solutions of extremal problems are studied
Dirichlet and Neumann Problems Related to Nonlinear Elliptic Systems: Solvability, Multiple Solutions, Solutions with Positive Components
Full text linkWe study the solvability of Dirichlet and Neumann problems for different classes of nonlinear elliptic systems depending on parameters and with nonmonotone operators, using existence theorems related to a general system of variational equations in a reflexive Banach space. We also point out some regularity properties and the sign of the found solutions components. We often prove the existence of at least two different solutions with positive components
A New Result Concerning the Solvability of a Class of General Systems of Variational Equations with Nonmonotone Operators: Applications to Dirichlet and Neumann Nonlinear Problems
Full text linkA new result of solvability for a wide class of systems of variational equations depending on parameters and governed by nonmonotone operators is found in a Banach real and reflexive space with applications to Dirichlet and Neumann problems related to nonlinear elliptic systems
- …
