English

Balayage of charge distributions and subharmonic functions onto a strip

Complex Variables 2022-04-20 v3

Abstract

We consider two balayage constructions on the complex plane C\mathbb C with real axis R\mathbb R for 0bR0\leq b\in \mathbb R. Let u≢u\not\equiv -\infty be a subharmonic function on C\mathbb C of order ord[u]:=lim supzlnmax{1,u(z)}lnz1,\operatorname{ord}[u]:=\limsup_{z\to \infty} \frac{\ln \max\{1,u(z)\}}{\ln |z|}\leq 1, U=uvU=u-v be the difference of subharmonic functions uu and v≢v\not\equiv -\infty on C\mathbb C with ord[v]1\operatorname{ord}[v]\leq 1, i.e., δ\delta-subharmonic function on C\mathbb C of order ord[U]1\operatorname{ord}[U]\leq 1. Then there is a δ\delta-subharmonic function V≢±V\not\equiv \pm\infty on C\mathbb C of order ord[V]1\operatorname{ord}[V]\leq 1 such that VV is harmonic on {zCz>b}\bigl\{ z \in \mathbb C\bigm| |\Re z|> b\bigr\} and U(z)V(z)U(z)\equiv V(z) for all z{zCzb}Ez\in \bigl\{ z \in \mathbb C\bigm| |\Re z|\leq b\bigr\}\setminus E where ECE\subset \mathbb C is polar. If uu is a subharmonic function of finite type under order 11, i.e., lim supzu(z)z<+,\limsup_{z\to \infty} \frac{u(z)}{|z|}<+\infty, then there exist subharmonic functions uRu_{\mathbb R} and ubu_b of finite type under order 11 that are harmonic respectively on CR\mathbb C\setminus \mathbb R and {zCz>b}\bigl\{ z \in \mathbb C\bigm| |\Re z|> b\bigr\} such that {u(z)uR(z)+ub(z) for all zR{zCzb},u(z)uR(z)+ub(z) for each zC.\begin{cases} u(z)\equiv u_{\mathbb R}(z)+u_b(z) \text{ for all $z\in {\mathbb R}\bigcup \bigl\{ z \in \mathbb C\bigm| |\Re z|\leq b\bigr\}$},\\ u(z)\leq u_{\mathbb R}(z) + u_b(z) \text{ for each $z\in \mathbb C$.}\end{cases} At the same time, we trace special relationships between the various logarithmic characteristics of the Riesz mass and charge distributions of subharmonic and δ\delta-subharmonic functions.

Keywords

Cite

@article{arxiv.2204.07461,
  title  = {Balayage of charge distributions and subharmonic functions onto a strip},
  author = {B. N. Khabibullin},
  journal= {arXiv preprint arXiv:2204.07461},
  year   = {2022}
}

Comments

13 pages, in Russian