Generalized trapezoid type inequalities for functions with values in Banach spaces
نویسندگان
1 Victoria University, Melbourne, Australia.
doi
10.30504/jims.2021.299742.1038چکیده
Let $E$ be a complex Banach space. In this paper we show among others that, if $\alpha :\left[ a,b\right] \rightarrow \mathbb{C}$ is continuous and $Y: \left[ a,b\right] \rightarrow E$ is strongly differentiable on the interval $ \left( a,b\right) ,$ then for all $u\in \left[ a,b\right] ,$ \begin{align*} & \left\Vert \left( \int_{u}^{b}\alpha \left( s\right) ds\right) Y\left( b\right) +\left( \int_{a}^{u}\alpha \left( s\right) ds\right) Y\left( a\right) -\int_{a}^{b}\alpha \left( t\right) Y\left( t\right) dt\right\Vert \\ & \leq \left\{ \begin{array}{l} \max \left\{ \int_{u}^{b}\left\vert \alpha \left( s\right) \right\vert ds,\int_{a}^{u}\left\vert \alpha \left( s\right) \right\vert ds\right\} \int_{a}^{b}\left\Vert Y^{\prime }\left( t\right) \right\Vert dt, \\ \left[ \int_{u}^{b}\left( b-t\right) \left\vert \alpha \left( t\right) \right\vert dt+\int_{a}^{u}\left( t-a\right) \left\vert \alpha \left( t\right) \right\vert dt\right] \sup_{t\in \left[ a,b\right] }\left\Vert Y^{\prime }\left( t\right) \right\Vert , \\ \leq \left( b-a\right) ^{1/p}\left[ \left( \int_{u}^{b}\left\vert \alpha \left( s\right) \right\vert ds\right) ^{p}+\left( \int_{a}^{u}\left\vert \alpha \left( s\right) \right\vert ds\right) ^{p}\right] ^{1/p} \\ \times \left( \int_{a}^{b}\left\Vert Y^{\prime }\left( t\right) \right\Vert ^{q}dt\right) ^{1/q} \end{array} \right. \end{align*} for $p,$ $q>1$ with $\frac{1}{p}+\frac{1}{q}=1.$ Applications for operator monotone functions with examples for power and logarithmic functions are also given.