Bounds for an integral involving the modified Struve function of the first kind

Robert E. Gaunt

Published 2021-01-27Version 1

Simple upper and lower bounds are established for the integral $\int_0^x\mathrm{e}^{-\beta t}t^\nu \mathbf{L}_\nu(t)\,\mathrm{d}t$, where $x>0$, $\nu>-1$, $0<\beta<1$ and $\mathbf{L}_\nu(x)$ is the modified Struve function of the first kind. These bounds complement and improve on existing results, through either sharper bounds or increased ranges of validity. In deriving our bounds, we obtain some monotonicity results and inequalities for products of the modified Struve function of the first kind and the modified Bessel function of the second kind $K_{\nu}(x)$, as well as a new bound for the ratio $\mathbf{L}_{\nu}(x)/\mathbf{L}_{\nu-1}(x)$.