Generalized Ordinary Differential Equations in Abstract Spaces and Applications. Группа авторов

Чтение книги онлайн.

Читать онлайн книгу Generalized Ordinary Differential Equations in Abstract Spaces and Applications - Группа авторов страница 45

Generalized Ordinary Differential Equations in Abstract Spaces and Applications - Группа авторов

Скачать книгу

delta less-than epsilon EndLayout"/>

      and the Claim is proved.

      A less restrict version of the Fundamental Theorem of Calculus is stated next. A proof of it follows as in [108, Theorem 9.6].

      Theorem 1.75 (Fundamental Theorem of Calculus): Suppose is a continuous function such that there exists the derivative , for nearly everywhere on i.e. except for a countable subset of . Then, and

integral Subscript a Superscript t Baseline f left-parenthesis s right-parenthesis d s equals upper F left-parenthesis t right-parenthesis minus upper F left-parenthesis a right-parenthesis comma t element-of left-bracket a comma b right-bracket period

      Now, we present a class of functions f colon left-bracket a comma b right-bracket right-arrow upper X, laying between absolute continuous and continuous functions, for which we can obtain a version of the Fundamental Theorem of Calculus for Henstock vector integrals. Let m denote the Lebesgue measure.

      If we denote by upper A upper C left-parenthesis left-bracket a comma b right-bracket comma upper X right-parenthesis the space of all absolutely continuous functions from left-bracket a comma b right-bracket to upper X, then it is not difficult to prove that

upper A upper C left-parenthesis left-bracket a comma b right-bracket comma upper X right-parenthesis subset-of upper S upper L left-parenthesis left-bracket a comma b right-bracket comma upper X right-parenthesis subset-of upper C left-parenthesis left-bracket a comma b right-bracket comma upper X right-parenthesis period

      In upper S upper L left-parenthesis left-bracket a comma b right-bracket comma upper X right-parenthesis, we consider the usual supremum norm, parallel-to dot parallel-to Subscript infinity Baseline, induced by upper C left-parenthesis left-bracket a comma b right-bracket comma upper X right-parenthesis.

      The next two versions of the Fundamental Theorem of Calculus for Henstock vector integrals, as described in Definition 1.41, are borrowed from [70, Theorems 1 and 2]. We use the term almost everywhere in the sense of the Lebesgue measure m.

      Theorem 1.77: If and are both differentiable and is such that for almost every , then and , that is,

integral Subscript a Superscript t Baseline alpha left-parenthesis s right-parenthesis f prime left-parenthesis s right-parenthesis d s equals integral Subscript a Superscript t Baseline alpha left-parenthesis s right-parenthesis d f left-parenthesis s right-parenthesis comma t element-of left-bracket a comma b right-bracket period

      Theorem 1.78: If is differentiable and is bounded, then , and there exists the derivative for almost every , that is,

StartFraction d Over d t EndFraction left-bracket integral Subscript a Superscript t Baseline alpha left-parenthesis s right-parenthesis d f left-parenthesis s right-parenthesis right-bracket equals alpha left-parenthesis t right-parenthesis f prime left-parenthesis t right-parenthesis comma almost everywhere in left-bracket a comma b right-bracket period

      Corollary 1.79: Suppose is differentiable and nonconstant on any nondegenerate subinterval of and is bounded and such that . Then, almost everywhere in .

      From Corollary 1.50, we know that if f element-of upper C left-parenthesis left-bracket a comma b right-bracket comma upper X right-parenthesis and alpha element-of upper K Subscript f Baseline left-parenthesis left-bracket a comma b right-bracket comma upper L left-parenthesis upper X comma upper Y right-parenthesis right-parenthesis, then alpha overTilde Subscript f Baseline element-of upper C left-parenthesis left-bracket a comma b right-bracket comma upper Y right-parenthesis. For the Henstock vector integral, we have the following analogue whose proof can be found in [70, Theorem 7].

      Theorem 1.80: If and , then we have .

      The next result is borrowed from [70, Theorem 5]. We reproduce its proof here.

      Theorem 1.81: Suppose and is such that almost everywhere on . Then, and , that

Скачать книгу