Ordinary differential equations, transport theory and Sobolev spaces.
Osgood type conditions for an m th-order differential equation
We present a new theorem on the differential inequality . Next, we apply this result to obtain existence theorems for the equation .
Parametrized relaxation for evolution inclusions of the subdifferential type
In this paper we consider parametric nonlinear evolution inclusions driven by time-dependent subdifferentials. First we prove some continuous dependence results for the solution set (of both the convex and nonconvex problems) and for the set of solution-selector pairs (of the convex problem). Then we derive a continuous version of the “Filippov-Gronwall” inequality and using it, we prove the parametric relaxation theorem. An example of a parabolic distributed parameter system is also worked out...
Periodic and aqlmost-periodic solutions of semihnear equations in Banach spaces.
Periodic boundary value problem in Hilbert space for differential equation of second order with reflection of the argument
Periodic problems for ODEs via multivalued Poincaré operators
We shall consider periodic problems for ordinary differential equations of the form where satisfies suitable assumptions. To study the above problem we shall follow an approach based on the topological degree theory. Roughly speaking, if on some ball of , the topological degree of, associated to (), multivalued Poincaré operator turns out to be different from zero, then problem () has solutions. Next by using the multivalued version of the classical Liapunov-Krasnoselskǐ guiding potential...
Periodic Solutions for Nonlinear Evolution Equations with Non-instantaneous Impulses
In this paper, we consider periodic solutions for a class of nonlinear evolution equations with non-instantaneous impulses on Banach spaces. By constructing a Poincaré operator, which is a composition of the maps and using the techniques of a priori estimate, we avoid assuming that periodic solution is bounded like in [1-4] and try to present new sufficient conditions on the existence of periodic mild solutions for such problems by utilizing semigroup theory and Leray-Schauder's fixed point theorem....
Periodic solutions for nonlinear evolution inclusions
In this paper we prove the existence of periodic solutions for a class of nonlinear evolution inclusions defined in an evolution triple of spaces and driven by a demicontinuous pseudomonotone coercive operator and an upper semicontinuous multivalued perturbation defined on with values in . Our proof is based on a known result about the surjectivity of the sum of two operators of monotone type and on the fact that the property of pseudomonotonicity is lifted to the Nemitsky operator, which we...
Periodic solutions for quasilinear vector differential equations with maximal monotone terms
We consider a quasilinear vector differential equation with maximal monotone term and periodic boundary conditions. Approximating the maximal monotone operator with its Yosida approximation, we introduce an auxiliary problem which we solve using techniques from the theory of nonlinear monotone operators and the Leray-Schauder principle. To obtain a solution of the original problem we pass to the limit as the parameter λ > 0 of the Yosida approximation tends to zero.
Periodic solutions of abstract differential equations: the Fourier method
Periodic solutions of semilinear impulsive periodic system with time-varying generating operators on Banach space.
Periodic solutions to evolution equations: existence, conditional stability and admissibility of function spaces
We prove the existence and conditional stability of periodic solutions to semilinear evolution equations of the form u̇ = A(t)u + g(t,u(t)), where the operator-valued function t ↦ A(t) is 1-periodic, and the operator g(t,x) is 1-periodic with respect to t for each fixed x and satisfies the φ-Lipschitz condition ||g(t,x₁) - g(t,x₂)|| ≤ φ(t)||x₁-x₂|| for φ(t) being a real and positive function which belongs to an admissible function space. We then apply the results to study the existence, uniqueness...
Périodicite des solutions d'equations differentielles dans les espaces de Banach.
Persistence of Crandall-Rabinowitz type bifurcations under small perturbations.
Perturbations of Positive Semigroups and Applications to Population Genetics.
Porous medium equation and fast diffusion equation as gradient systems
We show that the Porous Medium Equation and the Fast Diffusion Equation, , with , can be modeled as a gradient system in the Hilbert space , and we obtain existence and uniqueness of solutions in this framework. We deal with bounded and certain unbounded open sets and do not require any boundary regularity. Moreover, the approach is used to discuss the asymptotic behaviour and order preservation of solutions.
Positive solutions for a class of fourth-order boundary value problems in Banach spaces.
Positive solutions for a high-order multi-point boundary-value problem in Banach spaces.
Positive solutions for impulsive equations of third order in Banach space.
Positive solutions for second-order multi-point boundary-value problems at resonance in Banach spaces.