Progress on Hardy-type Inequalities

This paper surveys some of our recent progress on Hardy-type inequa\-lities which consist of a well-known topic in Harmonic Analysis. In the first section, we recall the original probabilistic motivation dealing with the stability speed in terms of the $L^2$-theory. A crucial application of a result by Fukushima and Uemura (2003) is included. In the second section, the non-linear case (a general Hardy-type inequality) is handled with a direct and analytic proof. In the last section, it is illustrated that the basic estimates presented in the first two sections can still be improved considerably.Comment: 13 pages, 5 figures, Festschrift Masatoshi Fukushima: In Honor of Masatoshi Fukushima's Sanju. World Scientific, 201

A Nonabelian (1,0)(1,0) Tensor Multiplet Theory in 6D

We construct a general nonabelian (1,0) tensor multiplet theory in six dimensions. The gauge field of this (1,0) theory is non-dynamical, and the theory contains a continuous parameter $b$. When $b=1/2$, the (1,0) theory possesses an extra discrete symmetry enhancing the supersymmetry to (2,0), and the theory turns out to be identical to the (2,0) theory of Lambert and Papageorgakis (LP). Upon dimension reduction, we obtain a general ${\cal N}=1$ supersymmetric Yang-Mills theory in five dimensions. The applications of the theories to D4 and M5-branes are briefly discussed.Comment: 18 pages, published in JHEP. minor changes, references adde

General estimate of the first eigenvalue on manifolds

Ten sharp lower estimates of the first non-trivial eigenvalue of Laplacian on compact Riemannian manifolds are reviewed and compared. An improved variational formula, a general common estimate, and a new sharp one are added. The best lower estimates are now updated. The new estimates provide a global picture of what one can expect by our approach.Comment: 19 page