†Department of Mathematics, Southeast University, Nanjing 210096, China ‡College of Mathematics and Information Science, Guangxi University, Nanning 530004, China E-mail: [email protected] E-mail: [email protected] E-mail: [email protected] Abstract: It is well known that for an associative ring R, if ab is Drazin invertible then ba is Drazin invertible. In this case, (ba)D = b((ab)D)2a. This for...

Based on the Padé approximation method, in this paper we determine the coefficients [Formula: see text] and [Formula: see text] ([Formula: see text]) such that [Formula: see text] where [Formula: see text] is any given integer. Based on the obtained result, we establish new upper bounds for [Formula: see text]. As an application, we give a generalized Carleman-type inequality.

a r t i c l e i n f o a b s t r a c t The Poincaré–Bertrand formula concerning two repeated Cauchy's principal integrals on a smooth curve in the plane is generalized to identities of singular integrals on smooth hypersurfaces in higher dimensions. Published by Elsevier Inc.

A generalized hyperbolic tetrahedra is a polyhedron (possibly noncompact) with finite volume in hyperbolic space, obtained from a tetrahedron by the polar truncation at the vertices lying outside the space. In this paper it is proved that a volume formula for ordinary hyperbolic tetrahedra devised by J. Murakami and M. Yano can be applied to such ones. There are two key tools for the proof; one...