211,594 research outputs found
The sign of the Green function of an n-th order linear boundary value problem
[EN] This paper provides results on the sign of the Green function (and its partial derivatives) of ann-th order boundary value problem subject to a wide set of homogeneous two-point boundary conditions. The dependence of the absolute value of the Green function and some of its partial derivatives with respect to the extremes where the boundary conditions are set is also assessed.This work has been supported by the Spanish Ministerio de Economia, Industria y Competitividad (MINECO), the Agencia Estatal de Investigacion (AEI) and Fondo Europeo de Desarrollo Regional (FEDER UE) grant MTM2017-89664-P.Almenar, P.; Jódar Sánchez, LA. (2020). The sign of the Green function of an n-th order linear boundary value problem. Mathematics. 8(5):1-22. https://doi.org/10.3390/math8050673S12285Butler, G. ., & Erbe, L. . (1983). Integral comparison theorems and extremal points for linear differential equations. Journal of Differential Equations, 47(2), 214-226. doi:10.1016/0022-0396(83)90034-7Peterson, A. C. (1979). Green’s functions for focal type boundary value problems. Rocky Mountain Journal of Mathematics, 9(4). doi:10.1216/rmj-1979-9-4-721Peterson, A. C. (1980). Focal Green’s functions for fourth-order differential equations. Journal of Mathematical Analysis and Applications, 75(2), 602-610. doi:10.1016/0022-247x(80)90104-3Elias, U. (1980). Green’s functions for a non-disconjugate differential operator. Journal of Differential Equations, 37(3), 318-350. doi:10.1016/0022-0396(80)90103-5Nehari, Z. (1967). Disconjugate linear differential operators. Transactions of the American Mathematical Society, 129(3), 500-500. doi:10.1090/s0002-9947-1967-0219781-0Keener, M. S., & Travis, C. C. (1978). Positive Cones and Focal Points for a Class of nth Order Differential Equations. Transactions of the American Mathematical Society, 237, 331. doi:10.2307/1997625Schmitt, K., & Smith, H. L. (1978). Positive solutions and conjugate points for systems of differential equations. Nonlinear Analysis: Theory, Methods & Applications, 2(1), 93-105. doi:10.1016/0362-546x(78)90045-7Eloe, P. W., Hankerson, D., & Henderson, J. (1992). Positive solutions and conjugate points for multipoint boundary value problems. Journal of Differential Equations, 95(1), 20-32. doi:10.1016/0022-0396(92)90041-kEloe, P. W., & Henderson, J. (1994). Focal Point Characterizations and Comparisons for Right Focal Differential Operators. Journal of Mathematical Analysis and Applications, 181(1), 22-34. doi:10.1006/jmaa.1994.1003Almenar, P., & Jódar, L. (2015). Solvability ofNth Order Linear Boundary Value Problems. International Journal of Differential Equations, 2015, 1-19. doi:10.1155/2015/230405Almenar, P., & Jódar, L. (2016). Improving Results on Solvability of a Class ofnth-Order Linear Boundary Value Problems. International Journal of Differential Equations, 2016, 1-10. doi:10.1155/2016/3750530Almenar, P., & Jodar, L. (2017). SOLVABILITY OF A CLASS OF N -TH ORDER LINEAR FOCAL PROBLEMS. Mathematical Modelling and Analysis, 22(4), 528-547. doi:10.3846/13926292.2017.1329757Sun, Y., Sun, Q., & Zhang, X. (2014). Existence and Nonexistence of Positive Solutions for a Higher-Order Three-Point Boundary Value Problem. Abstract and Applied Analysis, 2014, 1-7. doi:10.1155/2014/513051Hao, X., Liu, L., & Wu, Y. (2015). Iterative solution to singular nth-order nonlocal boundary value problems. Boundary Value Problems, 2015(1). doi:10.1186/s13661-015-0393-6Webb, J. R. L. (2017). New fixed point index results and nonlinear boundary value problems. Bulletin of the London Mathematical Society, 49(3), 534-547. doi:10.1112/blms.12055Jiang, D., & Yuan, C. (2010). The positive properties of the Green function for Dirichlet-type boundary value problems of nonlinear fractional differential equations and its application. Nonlinear Analysis: Theory, Methods & Applications, 72(2), 710-719. doi:10.1016/j.na.2009.07.012Wang, Y., & Liu, L. (2017). Positive properties of the Green function for two-term fractional differential equations and its application. The Journal of Nonlinear Sciences and Applications, 10(04), 2094-2102. doi:10.22436/jnsa.010.04.63Zhang, L., & Tian, H. (2017). Existence and uniqueness of positive solutions for a class of nonlinear fractional differential equations. Advances in Difference Equations, 2017(1). doi:10.1186/s13662-017-1157-7Wang, Y. (2020). The Green’s function of a class of two-term fractional differential equation boundary value problem and its applications. Advances in Difference Equations, 2020(1). doi:10.1186/s13662-020-02549-
Generalized vector valued almost periodic and ergodic distributions
For \Cal A\subset L^1_{loc}(\Bbb J,X) let \Cal M\Cal A consist of all
with M_h f (\cdot):=\frac {1}{h}\int_{0}^{h}f(\cdot +s)\,ds
\in \Cal A for all . Here is a Banach space, or . Usually \Cal A\subset\Cal M\Cal
A\subset \Cal M^2\Cal A\subset ....
The map \Cal A \to \Cal {D}'_{\Cal A} is iteration complete, that is
\Cal {D}'_{\Cal {D}'_{\Cal A}}= \Cal {D}'_{\Cal A}. Under suitable assumptions
\widetilde {\Cal M}^n \Cal {A}= \Cal A + \{T^{(n)} : T \in \Cal A\}, and
similarly for \Cal {M}^n \Cal A. Almost periodic -valued distributions
\h'_{\A} with \A = almost periodic (ap) functions are characterized in
several ways.
Various generalizations of the Bohl-Bohr-Kadets theorem on the almost
periodicity of the indefinite integral of an ap or almost automorphic function
are obtained.
On \Cal {D}'_{\Cal E} , \Cal E the class of ergodic functions, a mean
can be constructed which gives Fourier series. Special cases of \Cal A are
the Bohr ap, Stepanoff ap, almost automorphic, asymptotically ap, Eberlein
weakly ap, pseudo ap and (totally) ergodic functions (\T)\E.
Then always \Cal {M}^n \Cal A is strictly contained in \Cal {M}^{n+1}
\Cal A. The relations between \m^n \E, \m^n\T\E and subclasses are
discussed. For many of the above results a new -condition is needed,
we show that it holds for most of the \A needed in applications.
Also, we obtain new tauberian theorems for to
belong to a class \A which are decisive in describing the asymptotic behavior
of unbounded solutions of many abstract differential-integral equations. This
generalizes various recent resultsComment: 69 page
Existence Results for Some Damped Second-Order Volterra Integro-Differential Equations
In this paper we make a subtle use of operator theory techniques and the
well-known Schauder fixed-point principle to establish the existence of
pseudo-almost automorphic solutions to some second-order damped
integro-differential equations with pseudo-almost automorphic coefficients. In
order to illustrate our main results, we will study the existence of
pseudo-almost automorphic solutions to a structurally damped plate-like
boundary value problem.Comment: 20 pages. arXiv admin note: substantial text overlap with
arXiv:1402.563
A new effective weighted modified perturbation technique for solving a class of hypersingular integral equations
This paper is an attempt to solve an important class of hypersingular
integral equations of the second kind. To this end, we apply a new weighted and
modified perturbation method which includes some special cases of the Adomian
decomposition method. To justify the efficiency and applicability of the
proposed method, we examine some examples. The principal aspects of this method
are its simplicity along with fast computations
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