The special case I of the Kholodenko-Silagadze multiple integral considered anew
arXiv:1410.5788
Abstract
The nested Kholodenko-Silagadze quadrature \[ I_{n} = \int_{-\infty}^{\;\infty}ds_{1}\int_{-\infty}^{\;s_{1}}ds_{2}\int_{-\infty}^{\;s_{2}}ds_{3}\cdots \int_{-\infty}^{\;s_{2n-3}}ds_{2n-2}\int_{-\infty}^{\;s_{2n-2}}ds_{2n-1}\int_{-\infty}^{\;s_{2n-1}}ds_{2n}\cos(s_{1}^{2}-s_{2}^{2})\cos(s_{3}^{2}-s_{4}^{2})\cdots\cos(s_{2n-3}^{2}-s_{2n-2}^{2})\cos(s_{2n-1}^{2}-s_{2n}^{2})= \frac{2}{n!}\left(\fracπ{4}\right)^{n} \;, \] obtained for all integers by an elegant but indirect argument, is tackled anew from a uniform quadrature reduction viewpoint. Along the way, at its first instance of real difficulty when the recondite quadrature \[ \int_{\,0}^{\;\infty} \frac{\cos(u)}{u} du \int_{\,0}^{\,u} \frac{\sin^{2}(v)}{v}dv + \int_{\,0}^{\;\infty} \frac{\sin(u)}{u} du \int_{\,0}^{\,u} \frac{\sin(v)\cos(v)}{v}dv = \,\frac{π^{2}}{12}\;,\] heretofore presumably unknown, receives an indirect resolution with its indicated value of .
9 pages total: title, abstract, plus 7 pages of text; external abstract formatting improved; minor typos lifted from text in abstract and on p. 1; Footnote 1 added at the bottom of p. 6; Section 5 amplified somewhat and its numerical estimates slightly revised; minor text glosses elsewhere; mathematics totally unchanged