English

An example of limit of Lempert Functions

Complex Variables 2007-05-23 v2

Abstract

The Lempert function for several poles a0,...,aNa_0, ..., a_N in a domain Ω\Omega of Cn\mathbb C^n is defined at the point zΩz \in \Omega as the infimum of j=0Nlogζj\sum^N_{j=0} \log|\zeta_j| over all the choices of points ζj\zeta_j in the unit disk so that one can find a holomorphic mapping from the disk to the domain Ω\Omega sending 0 to zz. This is always larger than the pluricomplex Green function for the same set of poles, and in general different. Here we look at the asymptotic behavior of the Lempert function for three poles in the bidisk (the origin and one on each axis) as they all tend to the origin. The limit of the Lempert functions (if it exists) exhibits the following behavior: along all complex lines going through the origin, it decreases like (3/2)logz(3/2) \log |z|, except along three exceptional directions, where it decreases like 2logz2 \log |z|. The (possible) limit of the corresponding Green functions is not known, and this gives an upper bound for it.

Keywords

Cite

@article{arxiv.math/0601642,
  title  = {An example of limit of Lempert Functions},
  author = {Pascal J. Thomas},
  journal= {arXiv preprint arXiv:math/0601642},
  year   = {2007}
}

Comments

16 pages; references added to related work of the author

R2 v1 2026-07-22T17:30:37.912Z