We study a lightlike hypersurface M of an indefinite nearly trans-Sasakian manifold M̄ with an (ℓ, m)-type connection such that the structure vector field ζ-->

In this paper, we will find a Seifert matrix for a class of pretzel links with a certain symmetry. Using the symmetry, we find formulae for the Alexander polynomials, determinants and signatures of the pretzel links.

Divide knots and links, defined by A’Campo in the singularity theory of complex curves, is a method to present knots or links by real plane curves. The present paper is a sequel of the author’s previous result that every knot in th...

Niebrzydowski and Przytycki conjectured that the torsion of rack and quandle homology of a dihedral quandle of order 2k is annihilated by k, unless k = 2^t for t...

Minkowski’s inequality is one of the most famous inequalities in mathematics, and has many applications. In this paper, we give Minkowski’s inequality for generalized variational integrals that are based on a supermultiplicative fu...

We show that selfadjoint operator extensions of minimal second order difference operators have only discrete spectrum when the odd order coefficient is unbounded but grows or decays according to specific conditions. Selfadjoint operator extensions...

This article concerns the class of rings which satisfy the property of inserting regular elements at zero products, and rings with such property are called regular-IFP. We study the structure of regular-IFP rings in relation to va...