Victoria Otero-Espinar
University of Santiago de Compostela
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Publication
Featured researches published by Victoria Otero-Espinar.
Boundary Value Problems | 2009
Bashir Ahmad; Victoria Otero-Espinar
We study the existence of solutions for a class of fractional differential inclusions with anti-periodic boundary conditions. The main result of the paper is based on Bohnenblust- Karlins fixed point theorem. Some applications of the main result are also discussed.
Advances in Difference Equations | 2006
Ravi P. Agarwal; Victoria Otero-Espinar; Kanishka Perera; Dolores R. Vivero
We study the theory of Sobolevs spaces of functions defined on a closed subinterval of an arbitrary time scale endowed with the Lebesgue Δ-measure; analogous properties to that valid for Sobolevs spaces of functions defined on an arbitrary open interval of the real numbers are derived.
Computers & Mathematics With Applications | 2000
Alberto Cabada; Victoria Otero-Espinar; Rodrigo López Pouso
Abstract This paper is devoted to the study of the existence of solutions of first-order difference equations verifying nonlinear conditions that involve the global behavior of the solution. We prove that the existence of lower and upper solutions warrants the existence of such solutions lying in the sector formed by the mentioned functions. We also can prove that some classical results for differential equations are not true in general for this case.
Journal of Difference Equations and Applications | 2008
Rahmat Ali Khan; Juan J. Nieto; Victoria Otero-Espinar
The method of upper and lower solutions and the generalised quasilinearization technique for second order nonlinear three-point time scale boundary value problems of the type are developed. A monotone sequence of solutions of linear problems converging uniformly and quadratically to a solution of the problem is obtained.
Journal of Difference Equations and Applications | 2003
F.Merdivenci Atici; Alberto Cabada; Victoria Otero-Espinar
We are concerned with proving the existence of positive solutions of a periodic boundary value problem for a discrete nonlinear equation We shall also obtain criteria which leads to nonexistence of positive solutions. Index theory for the positive smooth function f and lower and upper solutions when the function f is allowed to have nonconstant sign and to be singular at 0 are employed.
Computers & Mathematics With Applications | 2003
Alberto Cabada; Victoria Otero-Espinar
In this paper, we study the existence of solution of the nonlinear second-order difference problem with Neumann boundary conditions. Assuming the existence of a pair of ordered lower and upper solutions γ and β, we obtain optimal existence results for the case γ ≤ β and even for γ ≥ β. To this end, we do an exhaustive study of the values of the real parameters α and μ, for which the associated Greens function to the linear operator L[α,μ] uκ ≡ uκ+2 − 2 α uκ+1 + μ uκ with Neumann boundary conditions has fixed sign.
Advances in Difference Equations | 2008
Ravi P. Agarwal; Victoria Otero-Espinar; Kanishka Perera; Dolores R. Vivero
This paper is devoted to using perturbation and variational techniques to derive some sufficient conditions for the existence of multiple positive solutions in the sense of distributions to a singular second-order dynamic equation with homogeneous Dirichlet boundary conditions, which includes those problems related to the negative exponent Emden-Fowler equation.
Journal of Difference Equations and Applications | 2006
Victoria Otero-Espinar; Dolores R. Vivero
This paper is devoted to the study of the existence of extremal solutions to a first-order initial value problem on an interval of an arbitrary time scale. We prove the existence of extremal solutions for problems satisfying Carathéodorys conditions. Moreover, they are approximated uniformly by a sequence of lower and upper solutions to this problem, respectively. We also can warrant the existence and approximation of extremal solutions for the problem by relaxing their continuity properties.
Boundary Value Problems | 2013
Victoria Otero-Espinar; Tania Pernas-Castaño
The aim of this paper is to employ variational techniques and critical point theory to prove some conditions for the existence of solutions to a nonlinear impulsive dynamic equation with homogeneous Dirichlet boundary conditions. Also, we are interested in the solutions of the impulsive nonlinear problem with linear derivative dependence satisfying an impulsive condition.MSC:34B37, 34N05.
Advances in Difference Equations | 2009
Ana Gómez González; Victoria Otero-Espinar
This paper is devoted to derive some sufficient conditions for the existence and uniqueness of positive solutions to a singular second-order dynamic equation with Dirichlet boundary conditions.