activity
20242026
collaborators

23 papers

math.CA2026

Fractional Gagliardo--Nirenberg Inequalities: Pointwise Estimates,Sharp Asymptotics, and Optimal Target Spaces

Pingxu Hu, Yinqin Li, Dachun Yang +1

We establish two pointwise estimates for fractional difference operators, tracking explicitly the dependence of the constants on the smoothness index . Using these, with…

math.AP2026

Stability for the Affine Sobolev Inequality and its Critical Points for

Rupert L. Frank, Yinqin Li, Dachun Yang

We prove stability for the affine Sobolev inequality for exponents with best possible norm and best possible stability exponent. We also show a corresponding result for c…

math.FA2026

Compactness and Its Applications of Sobolev Spaces Associated with Ball Banach Function Spaces

Xiaosheng Lin, Dachun Yang, Wen Yuan +1

Let be a bounded Lipschitz domain in , and be a ball Banach function space on In this article, under some mild assu…

math.AP2026

A Counterexample to the Necessity of the Vanishing Carleson Condition for VMO Poisson Kernels

Xiaosheng Lin, Dachun Yang, Sibei Yang +2

In [Problem 3.2.23, CBMS Regional Conference Series in Mathematics 83, 1994], Kenig asked whether the vanishing Carleson condition is the necessary and sufficient for the logarithm…

math.AP2026

A Counterexample to Kenig's Interpolation Problem for Sobolev Spaces with Zero Boundary Conditions

Xiaosheng Lin, Dachun Yang, Sibei Yang +2

Let . In this article, we show that there exists a bounded domain such that, for any given $s\in(1,2)\setminus\{\frac32\…

math.FA2026

Variable Muckenhoupt Weights

Dachun Yang, Wen Yuan, Zongze Zeng

In this article, with introducing concepts of variable scalar weights and variable matrix weights, we seek a compreh…