On the existence of solutions of nonlinear integral equations in Banach spaces and Henstock-Kurzweil integrals

Aneta Sikorska-Nowak

Displaying similar documents to “On the existence of solutions of nonlinear integral equations in Banach spaces and Henstock-Kurzweil integrals”

Henstock-Kurzweil integral on $BV$ sets

Jan Malý, Washek Frank Pfeffer (2016)

Mathematica Bohemica

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The generalized Riemann integral of Pfeffer (1991) is defined on all bounded $BV$ subsets of $ℝ^{n}$ , but it is additive only with respect to pairs of disjoint sets whose closures intersect in a set of $σ$ -finite Hausdorff measure of codimension one. Imposing a stronger regularity condition on partitions of $BV$ sets, we define a Riemann-type integral which satisfies the usual additivity condition and extends the integral of Pfeffer. The new integral is lipeomorphism-invariant and closed with respect...

Variational Henstock integrability of Banach space valued functions

Luisa Di Piazza, Valeria Marraffa, Kazimierz Musiał (2016)

Mathematica Bohemica

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We study the integrability of Banach space valued strongly measurable functions defined on $[0, 1]$ . In the case of functions $f$ given by $\sum_{n = 1}^{\infty} x_{n} χ_{E_{n}}$ , where $x_{n}$ are points of a Banach space and the sets $E_{n}$ are Lebesgue measurable and pairwise disjoint subsets of $[0, 1]$ , there are well known characterizations for Bochner and Pettis integrability of $f$ . The function $f$ is Bochner integrable if and only if the series $\sum_{n = 1}^{\infty} x_{n} | E_{n} |$ is absolutely convergent. Unconditional convergence of the series is equivalent to Pettis integrability...

The $L^{r}$ Henstock-Kurzweil integral

Paul M. Musial, Yoram Sagher (2004)

Studia Mathematica

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We present a method of integration along the lines of the Henstock-Kurzweil integral. All $L^{r}$ -derivatives are integrable in this method.

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Wadie Aziz, José A. Guerrero, L. Antonio Azócar, Nelson Merentes (2016)

Discussiones Mathematicae, Differential Inclusions, Control and Optimization

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In this paper we study existence and uniqueness of solutions for the Hammerstein equation $u (x) = v (x) + λ \int_{I_{a}^{b}} K (x, y) f (y, u (y)) d y$ in the space of function of bounded total $ϕ$ -variation in the sense of Hardy-Vitali-Tonelli, where $λ \in ℝ$ , $K : I_{a}^{b} \times I_{a}^{b} ⟶ ℝ$ and $f : I_{a}^{b} \times ℝ ⟶ ℝ$ are suitable functions. The existence and uniqueness of solutions are proved by means of the Leray-Schauder nonlinear alternative and the Banach contraction mapping principle.

Boundary value problems for the Schrödinger equation involving the Henstock-Kurzweil integral

Salvador Sánchez-Perales, Francisco J. Mendoza-Torres (2020)

Czechoslovak Mathematical Journal

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In the present paper, we investigate the existence of solutions to boundary value problems for the one-dimensional Schrödinger equation $- y^{''} + q y = f$ , where $q$ and $f$ are Henstock-Kurzweil integrable functions on $[a, b]$ . Results presented in this article are generalizations of the classical results for the Lebesgue integral.

The only continuous Volterra right inverses in $C_{c} [0, 1]$ of the operator $d / d t$ are $ʃ_{a}^{t}$

D. Przeworska-Rolewicz, S. Rolewicz (1987)

Colloquium Mathematicae

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Continuity in the Alexiewicz norm

Erik Talvila (2006)

Mathematica Bohemica

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If $f$ is a Henstock-Kurzweil integrable function on the real line, the Alexiewicz norm of $f$ is $∥ f ∥ = {sup}_{I} | \int_{I} f |$ where the supremum is taken over all intervals $I \subset ℝ$ . Define the translation $τ_{x}$ by $τ_{x} f (y) = f (y - x)$ . Then $∥ τ_{x} f - f ∥$ tends to $0$ as $x$ tends to $0$ , i.e., $f$ is continuous in the Alexiewicz norm. For particular functions, $∥ τ_{x} f - f ∥$ can tend to 0 arbitrarily slowly. In general, $∥ τ_{x} f - f ∥ \geq osc f | x |$ as $x \to 0$ , where $osc f$ is the oscillation of $f$ . It is shown that if $F$ is a primitive of $f$ then $∥ τ_{x} F - F ∥ \leq ∥ f ∥ | x |$ . An example shows that the function $y \mapsto τ_{x} F (y) - F (y)$ need not be in $L^{1}$ . However, if...

Elementary construction of Hölder functions such that the Kurzweil-Stieltjes integral does not exist

Martin Rmoutil (2025)

Czechoslovak Mathematical Journal

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For any $α, β > 0$ with $α + β < 1$ we provide a simple construction of an $α$ -Hölde function $f : [0, 1] \to ℝ$ and a $β$ -Hölder function $g : [0, 1] \to ℝ$ such that the integral $\int_{0}^{1} f d g$ fails to exist even in the Kurzweil-Stieltjes sense.

Role of the Harnack extension principle in the Kurzweil-Stieltjes integral

Umi Mahnuna Hanung (2024)

Mathematica Bohemica

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In the theories of integration and of ordinary differential and integral equations, convergence theorems provide one of the most widely used tools. Since the values of the Kurzweil-Stieltjes integrals over various kinds of bounded intervals having the same infimum and supremum need not coincide, the Harnack extension principle in the Kurzweil-Henstock integral, which is a key step to supply convergence theorems, cannot be easily extended to the Kurzweil-type Stieltjes integrals with...

On coincidence of Pettis and McShane integrability

Marián J. Fabián (2015)

Czechoslovak Mathematical Journal

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R. Deville and J. Rodríguez proved that, for every Hilbert generated space $X$ , every Pettis integrable function $f : [0, 1] \to X$ is McShane integrable. R. Avilés, G. Plebanek, and J. Rodríguez constructed a weakly compactly generated Banach space $X$ and a scalarly null (hence Pettis integrable) function from $[0, 1]$ into $X$ , which was not McShane integrable. We study here the mechanism behind the McShane integrability of scalarly negligible functions from $[0, 1]$ (mostly) into $C (K)$ spaces. We focus in more detail on...