Search results for "integral"

Dual of the Class of HKr Integrable Functions

2019

We define for 1 <= r < infinity a norm for the class of functions which are Henstock-Kurzweil integrable in the L-r sense. We then establish that the dual in this norm is isometrically isomorphic to L-r' and is therefore a Banach space, and in the case r = 2, a Hilbert space. Finally, we give results pertaining to convergence and weak convergence in this space.

A variational henstock integral characterization of the radon-nikodým property

2009

A characterization of Banach spaces possessing the Radon-Nikodym property is given in terms of finitely additive interval functions. We prove that a Banach space X has the RNP if and only if each X-valued finitely additive interval function possessing absolutely continuous variational measure is a variational Henstock integral of an X-valued function. Due to that characterization several X-valued set functions that are only finitely additive can be represented as integrals.

Approximation of Banach space valued Riemann type integrable functions by step functions

2008

In this talk we consider the possibility to approximate (with respect to some topology induced by the Alexiewicz norm) non absolutely integrable functions defined on the unit interval by step functions. In particular we show that any Henstock (respectively Henstock-Kurzweil-Pettis, Denjoy-Khintchine-Pettis) integrable functions can be scalarly approximate in the Alexiewicz norm by a sequence of step functions. Moreover the approximation may be done in the Alexiewicz norm if and only if the range of the integral is relatively norm compact (property which is automatically satisfied by the Henstock integrable functions). We also provide an example to show that, unlike the Pettis case, Henstock…

MR3093276 Reviewed Naralenkov, K. M. On continuity and compactness of some vector-valued integrals. Rocky Mountain J. Math. 43 (2013), no. 3, 1015–10…

2014

ZBL MS 63/6 Satco, Bianca-Renata; Turcu, Corneliu-Octavian Henstock-Kurzweil-Pettis integral and weak topologies in nonlinear integral equations on t…

2013

The authors prove an existence result for a nonlinear integral equation on time scales under weak topology assumption in the target Banach space. In the setting of vector valued functions on time scales they consider the Henstock-Kurzweil-Pettis $\Delta$-integral which is a kind of Henstock integral recently introduced by Cichon, M. [Commun. Math. Anal. 11 (2011), no. 1, 94�110]. In this framework they show the existence of weakly continuous solutions for an integral equation x(t)= f(t, x(t))+ (HKP)\int_0^t g(t,s,x(s)) \Delta s governed by the sum of two operators: a continuous operator and an integral one. The main tool to get the solutions is a generalization of Krasnosel'skii fixed point…

THE HKr-INTEGRAL IS NOT CONTAINED IN THE Pr-INTEGRAL

2022

We compare a Perron-type integral with a Henstock-Kurzweiltype integral, both having been introduced to recover functions from their generalized derivatives defined in the metric Lr. We give an example of an HKr-integrable function which is not Pr-integrable, thereby showing that the first integral is strictly wider than the second one.

HENSTOCK- AND PERRON-TYPE INTEGRAL ON A COMPACT ZERO-DIMENSIONAL METRIC SPACE

2011

MR2657294 (2011h:28021) Bensimhoun, Michael Change of variable theorems for the KH integral. Real Anal. Exchange 35 (2010), no. 1, 167–194. (Reviewer…

2010

From Reviews: 0 MR2657294 (2011h:28021) Bensimhoun, Michael(IL-HEBR) Change of variable theorems for the KH integral. (English summary) Real Anal. Exchange 35 (2010), no. 1, 167–194. 28B05 (26A42 46G10) PDF Clipboard Journal Article Make Link Let $({\scr E},{\scr F}, {\scr G})$(E,F,G) be a Banach triple and let $f\colon [a,b] \subset \overline{\Bbb R} \rightarrow {\scr E}$f:[a,b]⊂R−−→E, $\varphi \colon [a,b] \rightarrow {\scr F}$φ:[a,b]→F and $\psi\colon [c,d] \subset \overline{\Bbb R} \rightarrow [a,b]$ψ:[c,d]⊂R−−→[a,b] be given. The problem of change of variables in an integral consists in finding the best conditions under which the equality $$ \int_c^d f \circ \psi \cdot d(\varphi \circ …

Recensione: MR3198633 Reviewed Olszowy, Leszek A family of measures of noncompactness in the space L1loc(R+) and its application to some nonlinear Vo…

2014

Decomposability in the space of HKP-integrable functions

2014

In this paper we introduce the notion of decomposability in the space of Henstock-Kurzweil-Pettis integrable (for short HKP-integrable) functions. We show representations theorems for decomposable sets of HKP-integrable or Henstock integrable functions, in terms of the family of selections of suitable multifunctions.