4 papers
math.AP2026
Riesz transform and its related inequalities for degenerate elliptic operators of Grushin type
Dangyang He
We study the boundedness of the Riesz transform and the reverse Riesz inequality for degenerate elliptic operators of Grushin type. We prove full-range boundedness of t…
math.CA2026
Isoperimetric Inequality for degenerate elliptic operators of Grushin type
Dangyang He
Let , , and . For the Grushin-type operator \[ L=-\nabla_x\!\cdot\!\bigl(|x|^{2α}\nabla_x\bigr)+|x|^{2β}Î_y \qquad \text{on } \mathbb R^n\times \m…
math.AP2025
On the Riesz transform and its reverse inequality on manifolds with quadratically decaying curvature
Dangyang He
We study Riesz and reverse Riesz inequalities on manifolds whose Ricci curvature decays quadratically. First, we refine existing results on the boundedness of the Riesz transform b…
math.FA2025
Isoperimetric Inequality on Manifolds with Quadratically Decaying Curvature
Dangyang He
In this paper, we investigate the reverse improvement property of Sobolev inequalities on manifolds with quadratically decaying Ricci curvature. Specifically, we establish conditio…