Properties of solutions of the differential equation xx'' - kx'...+ f(x) = 0.
In this paper we consider evolution inclusions driven by a time-dependent subdifferential. First we prove a relaxation result and then we use it to show that if the solution set is closed in a space of continuous functions, then the orientor field is almost everywhere convex valued.
Let , k = const > 0, j = 1,2, . Suppose that (*) for all k > 0, where p is an arbitrary fixed bounded piecewise-analytic function on [0,1], which changes sign finitely many times, and solves the problem , 0 ≤ x ≤ 1, , . It is proved that (*) implies p = 0. This result is applied to an inverse problem for a heat equation.
In this paper, for the impulsive fractional integro-differential equations involving Caputo fractional derivative in Banach space, we investigate the existence and uniqueness of a pseudo almost periodic -mild solution. The working tools are based on the fixed point theorems, the fractional powers of operators and fractional calculus. Some known results are improved and generalized. Finally, existence and uniqueness of a pseudo almost periodic -mild solution of a two-dimensional impulsive fractional...
Psi-series (i.e., logarithmic series) for the solutions of quadratic vector fields on the plane are considered. Its existence and convergence is studied, and an algorithm for the location of logarithmic singularities is developed. Moreover, the relationship between psi-series and non-integrability is stressed and in particular it is proved that quadratic systems with psi-series that are not Laurent series do not have an algebraic first integral. Besides, a criterion about non-existence of an analytic...