Searcharxiv⌕ Search

arXiv subjects

Bao Qin Li

Publications and source records attributed to Bao Qin Li.

6 recordsLinked to original sources

On Picard Type Theorems and Entire Solutions of Differential Equations

We give a connection between the Picard type theorem of Polya-Saxer-Milliox and characterization of entire solutions of a differential equation and then their higher dimensional extensions, which leads further results on both (ordinary and partial) differential equations and Picard type theorems.

math.CV↗

On the Number of Zeros and Poles of Dirichlet Series

This paper investigates lower bounds on the number of zeros and poles of a general Dirichlet series in a disk of radius $r$ and gives, as a consequence, an affirmative answer to an open problem of Bombieri and Perelli on the bound. Applications will also be given to Picard type theorems, global estimates on the symmetric difference of zeros, and uniqueness problems for Dirichlet series.

math.CV↗

Boundary limits for bounded quasiregular mappings

In this paper we establish results on the existence of nontangential limits for weighted $\Cal A$-harmonic functions in the weighted Sobolev space $W_w^{1,q}(\Bbb B^n)$, for some $q>1$ and $w$ in the Muckenhoupt $A_q$ class, where $\Bbb B^n$ is the unit ball in $\Bbb R^n$. These results generalize the ones in section \S3 of [KMV], where the weight was identically equal to one. Weighted $\Cal A$-harmonic functions are weak solutions of the partial differential equation $$\text{div}(\Cal A(x,\nabla u))=0,$$ where $αw(x) |ξ|^{q} \le < \Cal A(x,ξ),ξ>\le βw(x) |ξ|^{q}$ for some fixed $q\in (1,\infty)$, where $0<α\leq β<\infty$, and $w(x)$ is a $q$-admissible weight as in Chapter 1 in [HKM]. Later, we apply these results to improve on results of Koskela, Manfredi and Villamor [KMV] and Martio and Srebro [MS] on the existence of radial limits for bounded quasiregular mappings in the unit ball of $\Bbb R^n$ with some growth restriction on their multiplicity function.

math.CV↗