Hörmander's operators are an important class of linear elliptic-parabolic degenerate partial
differential operators with smooth coefficients, which have been intensively studied since the …

Harnack inequality for hypoelliptic ultraparabolic equations with a singular lower order term
Page 1 Rev. Mat. Iberoamericana 24 (2008), no. 3, 1011–1046 Harnack inequality for …

Let X1, X2,…, Xq be a system of real smooth vector fields satisfying Hörmander's rank
condition in a bounded domain Ω of Rn. Let [Formula: see text] be a symmetric, uniformly …

MEMOIRS Page 1 MEMOIRS of the American Mathematical Society Number 961 Non-Divergence
Equations Structured on Hormander Vector Fields: Heat Kernels and Harnack Inequalities …

Many more results have been proved in the literature for operators without the drift term
(“sum of squares” of Hörmander type) than for complete Hörmander's operators. On the …

Let L=− Δ+ V be a Schrödinger operator on Rd, d≥ 3, where V is a nonnegative potential,
V= 0, and belongs to the reverse Hölder class RHd/2. In this paper, we study the …

Let X be an RD-space. In this paper, the authors establish the boundedness of the
commutator T bf= bT f− T (bf) on L p, p∈(1,∞), where T is a Calderón-Zygmund operator …

We prove regularity results for solutions of the equation 1< p<∞, where X=(X1,…, Xm) is a
family of vector fields satisfying Hörmander's condition, and A is an m× m symmetric matrix …

Abstract Let X 0, X 1,…, X q be left invariant real vector fields on the homogeneous group G
and assume that X 1,…, X q are homogeneous of degree one and X 0 is homogeneous of …

We present a result of Lp continuity of singular integrals of Calderón-Zygmund type in the
context of bounded nonhomogeneous spaces, well suited to be applied to problems of a …