Dachun Yang

activity

20232026

most citedParabolic Muckenhoupt Weights Characterized by Parabolic Fractional Maximal and Integral Operators with Time Lag

4 citations · 4 across the 25 of their papers we have counts for

collaborators

30 papers

math.CA2026

Real-Variable Characterizations and Their Applications of Anisotropic Besov Spaces with Matrix $A_{\infty}$ Weights

Fan Bu, Shuaijun Feng, Qingying Xue +2

Let $α \in R$ , $p \in (0, \infty)$ , and $q \in (0, \infty]$ . In this article, we develop a theory of matrix-weighted anisotropic Besov spaces associated with an expansive matrix $…

math.AP2026

Stability for the Affine Sobolev Inequality and its Critical Points for $p \geq 2$

Rupert L. Frank, Yinqin Li, Dachun Yang

We prove stability for the affine Sobolev inequality for exponents $p \geq 2$ with best possible norm and best possible stability exponent. We also show a corresponding result for c…

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 $s \in (0, 1)$ . Using these, with…

math.FA2026

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

Xiaosheng Lin, Dachun Yang, Wen Yuan +1

Let $N \in N \cap [2, \infty),$ $Ω$ be a bounded Lipschitz domain in $R^{N}$ , and $X (Ω)$ be a ball Banach function space on $Ω.$ In this article, under some mild assumpt…

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 $n \in N \cap [2, \infty)$ . In this article, we show that there exists a bounded $C^{1}$ domain $Ω \subset R^{n}$ such that, for any given $s\in(1,2)\setminus\{\frac32\}…

math.FA2026

Variable Muckenhoupt $A_{\infty}$ Weights

Dachun Yang, Wen Yuan, Zongze Zeng

In this article, with introducing concepts of variable scalar $A_{p (\cdot), \infty}$ weights and variable matrix $A_{p (\cdot), \infty}$ weights, we seek a compreh…

math.FA2026

Real-variable theory of function spaces with operator-valued $A_{p}$ weights in Banach spaces

Tuomas P. Hytönen, Yinqin Li, Dachun Yang +1

While the theory of matrix-weighted function spaces is well established, the majority of previous results in the infinite-dimensional operator-valued setting deal with "no go" theo…

math.FA2026

Real-variable theory of matrix-weighted multi-parameter Besov--Triebel--Lizorkin-type spaces

Fan Bu, Yiqun Chen, Tuomas Hytönen +2

We develop a comprehensive theory for a general class of multi-parameter function spaces of Besov-Triebel-Lizorkin type, with a matrix weight. We prove the equivalence of different…

math.FA2026

Product Hardy Spaces on Spaces of Homogeneous Type: Discrete Product Calderón-Type Reproducing Formula, Atomic Characterization, and Product Calderón--Zygmund Operators

Ziyi He, Dachun Yang, Taotao Zheng

Let $i \in {1, 2}$ and $X_{i}$ be a space of homogeneous type in the sense of Coifman and Weiss with the upper dimension $ω_{i}$ . Also let $η_{i}$ be the smoothness index of the Auscher--…

math.FA2026

Matrix-Weighted Poincaré-Type Inequalities with Applications to Logarithmic Hajłasz--Besov Spaces on Spaces of Homogeneous Type

Ziwei Li, Dachun Yang, Wen Yuan

Let $X$ be a space of homogeneous type. In this article, based on the reducing operators of matrix $A_{p}$ -weights, the authors introduce the vector-valued Hajłasz gradi…

math.AP2026

One-Sided and Parabolic BLO Spaces with Time Lag and Their Applications to Muckenhoupt $A_{1}$ Weights and Doubly Nonlinear Parabolic Equations

Weiyi Kong, Dachun Yang, Wen Yuan

In this article, we first introduce the one-sided BLO space $BLO^{+} (R)$ and characterize it, respectively, in terms of the one-sided Muckenhoupt class $A_1^+(\math…

math.FA2026

A Sharp Localized Weighted Inequality Related to Gagliardo and Sobolev Seminorms and Its Applications

Pingxu Hu, Yinqin Li, Dachun Yang +1

In this article, we establish a nearly sharp localized weighted inequality related to Gagliardo and Sobolev seminorms, respectively, with the sharp $A_{1}$ -weight constant or with th…

math.FA2025

Maz'ya--Shaposhnikova Representation of Quasi-Norms of Ball Quasi-Banach Function Spaces on Spaces of Homogeneous Type with Weak Reverse Doubling Property

Eiichi Nakai, Menghao Tang, Dachun Yang +2

Let $Y (X)$ be a ball quasi-Banach function space on the space of homogeneous type $(X, ρ, μ)$ satisfying some mild additional assumptions, $q \in (0, \infty)$ , and $…

math.FA2025

Variable Matrix-Weighted Besov Spaces

Dachun Yang, Wen Yuan, Zongze Zeng

In this article, using variable matrix $A_{p (\cdot), \infty}$ weights, we introduce the matrix-weighted variable Besov space $B_{p (\cdot), q (\cdot)}^{s (\cdot)} (W)$ and th…

math.FA2025

Matrix-Weighted Campanato Spaces: Duality and Calderón--Zygmund Operators

Yiqun Chen, Dachun Yang, Wen Yuan

Let $p \in (0, \infty)$ , $q \in [1, \infty)$ , $s \in Z_{+}$ , and $W$ be an $A_{p}$ -matrix weight, which in the scalar case is exactly a Muckenhoupt $A_{m a x {1, p}}$ weight. In this ar…

math.FA2025

Characterization of Vanishing Campanato Spaces via Ball Banach Function Spaces and Its Applications

Xing Fu, Yoshihiro Sawano, Jin Tao +1

In this article, the authors provide some new characterizations of several vanishing Campanato spaces using a type of oscillation defined within the general framework of ball Banac…

math.FA2025

Difference and Wavelet Characterizations of Distances from Functions in Lipschitz Spaces to Their Subspaces

Feng Dai, Eero Saksman, Dachun Yang +2

Let $Λ_{s}$ denote the Lipschitz space of order $s \in (0, \infty)$ on $R^{n}$ , which consists of all $f \in C \cap L^{\infty}$ such that, for some constant $L\in(0,\infty)…

math.FA2025

Sharp Brezis--Seeger--Van Schaftingen--Yung Formulae for Higher-Order Gradients in Ball Banach Function Spaces

Pingxu Hu, Yinqin Li, Dachun Yang +2

Let $X$ be a ball Banach function space on $R^{n}$ , $k \in N$ , $h \in R^{n}$ , and $Δ_{h}^{k}$ denote the $k$ {\rm th} order difference. In this article, under some mi…

math.FA2025

Matrix-Weighted Besov--Triebel--Lizorkin Spaces of Optimal Scale: Boundedness of Pseudo-Differential, Trace, and Calderón--Zygmund Operators

Dachun Yang, Wen Yuan, Mingdong Zhang

This article is a continuation of our work on generalized matrix-weighted Besov--Triebel--Lizorkin-type spaces with matrix $A_{\infty}$ weights. In this article, we estab…

math.FA2025

Matrix-Weighted Besov-Triebel-Lizorkin Spaces of Optimal Scale: Real-Variable Characterizations, Invariance on Integrable Index, and Sobolev-Type Embedding

Fan Bu, Dachun Yang, Wen Yuan +1

In this article, using growth functions we introduce generalized matrix-weighted Besov-Triebel-Lizorkin-type spaces with matrix $A_{\infty}$ weights. We first characteriz…

math.FA2025

Parabolic Extrapolation and Its Applications to Characterizing Parabolic BMO Spaces via Parabolic Fractional Commutators

Mingming Cao, Weiyi Kong, Dachun Yang +2

In this article, we establish the parabolic version of the celebrated Rubio de Francia extrapolation theorem. As applications, we obtain new characterizations of parabolic BMO-type…

math.FA2025

Maximal Function and Atomic Characterizations of Matrix-Weighted Hardy Spaces with Their Applications to Boundedness of Calderón--Zygmund Operators

Fan Bu, Yiqun Chen, Dachun Yang +1

Let $p \in (0, 1]$ and $W$ be an $A_{p}$ -matrix weight, which in scalar case is exactly a Muckenhoupt $A_{1}$ weight. In this article, we introduce matrix-weighted Hardy spaces $H_{W}^{p}$ vi…

math.FA2024

Regularity of Characteristic Functions in Besov-Type and Triebel--Lizorkin-Type Spaces

Wen Yuan, Winfried Sickel, Dachun Yang

In this article, the authors determine the optimal regularity of characteristic functions in Besov-type and Triebel--Lizorkin-type spaces under restrictions on the measure of the $…

Real-Variable Characterizations and Their Applications of Anisotropic Besov Spaces with Matrix A∞​ Weights

Stability for the Affine Sobolev Inequality and its Critical Points for p≥2

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

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

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

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

Variable Muckenhoupt A∞​ Weights

Real-variable theory of function spaces with operator-valued Ap​ weights in Banach spaces

Real-variable theory of matrix-weighted multi-parameter Besov--Triebel--Lizorkin-type spaces

Product Hardy Spaces on Spaces of Homogeneous Type: Discrete Product Calderón-Type Reproducing Formula, Atomic Characterization, and Product Calderón--Zygmund Operators

Matrix-Weighted Poincaré-Type Inequalities with Applications to Logarithmic Hajłasz--Besov Spaces on Spaces of Homogeneous Type

One-Sided and Parabolic BLO Spaces with Time Lag and Their Applications to Muckenhoupt A1​ Weights and Doubly Nonlinear Parabolic Equations

A Sharp Localized Weighted Inequality Related to Gagliardo and Sobolev Seminorms and Its Applications

Maz'ya--Shaposhnikova Representation of Quasi-Norms of Ball Quasi-Banach Function Spaces on Spaces of Homogeneous Type with Weak Reverse Doubling Property

Variable Matrix-Weighted Besov Spaces

Matrix-Weighted Campanato Spaces: Duality and Calderón--Zygmund Operators

Characterization of Vanishing Campanato Spaces via Ball Banach Function Spaces and Its Applications

Difference and Wavelet Characterizations of Distances from Functions in Lipschitz Spaces to Their Subspaces

Sharp Brezis--Seeger--Van Schaftingen--Yung Formulae for Higher-Order Gradients in Ball Banach Function Spaces

Matrix-Weighted Besov--Triebel--Lizorkin Spaces of Optimal Scale: Boundedness of Pseudo-Differential, Trace, and Calderón--Zygmund Operators

Matrix-Weighted Besov-Triebel-Lizorkin Spaces of Optimal Scale: Real-Variable Characterizations, Invariance on Integrable Index, and Sobolev-Type Embedding

Parabolic Extrapolation and Its Applications to Characterizing Parabolic BMO Spaces via Parabolic Fractional Commutators

Maximal Function and Atomic Characterizations of Matrix-Weighted Hardy Spaces with Their Applications to Boundedness of Calderón--Zygmund Operators

Regularity of Characteristic Functions in Besov-Type and Triebel--Lizorkin-Type Spaces

Real-Variable Characterizations and Their Applications of Anisotropic Besov Spaces with Matrix $A_{\infty}$ Weights

Stability for the Affine Sobolev Inequality and its Critical Points for $p \geq 2$

Variable Muckenhoupt $A_{\infty}$ Weights

Real-variable theory of function spaces with operator-valued $A_{p}$ weights in Banach spaces

One-Sided and Parabolic BLO Spaces with Time Lag and Their Applications to Muckenhoupt $A_{1}$ Weights and Doubly Nonlinear Parabolic Equations