Let $ X $ be a metric space with doubling measure, and $ L $ be a non-negative, self-adjoint
operator satisfying Davies-Gaffney bounds on $ L^ 2 (X) $. In this article we present a theory …

Consider a second order divergence form elliptic operator L with complex bounded
measurable coefficients. In general, operators based on L, such as the Riesz transform or …

In this paper, we introduce and develop some new function spaces of BMO (bounded mean
oscillation) type on spaces of homogeneous type or measurable subsets of spaces of …

We introduce and explore Hardy spaces defined by mixed Lebesgue norms and anisotropic
dilations. We prove that the definitions of these spaces in terms of smooth, non-tangential …

Let A be an n× n matrix with entries (1.1) ajk: Rn−→ C, j= 1,..., n, k= 1,..., n, satisfying the
ellipticity condition (1.2) λ| ξ| 2≤ eAξ· ξ and| Aξ· ζ|≤ Λ| ξ|| ζ|,∀ ξ, ζ∈ Cn, for some constants …

Let L be the divergence form elliptic operator with complex bounded measurable
coefficients, ω the positive concave function on (0,∞) of strictly critical lower type pω∈(0, 1] …

We investigate Fourier multipliers on the compact dual of arbitrary discrete groups. Our main
result is a Hörmander–Mihlin multiplier theorem for finite-dimensional cocycles with optimal …

Let be a metric space with doubling measure, L a nonnegative self-adjoint operator in
satisfying the Davies–Gaffney estimate, ω a concave function on (0,∞) of strictly lower type …

Let ${\mathcal X} $ be an RD-space, which means that ${\mathcal X} $ is a space of
homogenous type in the sense of Coifman and Weiss with the additional property that a …

Let $ X $ be a space of homogeneous type and let $\mathfrak {L} $ be a nonnegative self-
adjoint operator on $ L^ 2 (X) $ enjoying Gaussian estimates. The main aim of this paper is …