26 research outputs found
Geometry of the symmetrized polydisc
We describe all proper holomorphic mappings of the symmetrized polydisc and
study its geometric properties. We also apply the obtained results to the study
of the spectral unit ball in \MM_n(\CC^n).Comment: 9 page
On Bergman completeness of non-hyperconvex domains
We study the problem of the boundary behaviour of the Bergman kernel and the
Bergman completeness in some classes of bounded pseudoconvex domains, which
contain also non-hyperconvex domains. Among the classes for which we prove the
Bergman completeness and the convergence of the Bergman kernel to infinity
while tending to the boundary are all bounded pseudoconvex balanced domains,
all bounded Hartogs domains with balanced fibers over regular domains and some
bounded Laurent-Hartogs domains.Comment: 13 page
Schwarz Lemma for the tetrablock
We describe all complex geodesics in the tetrablock passing through the
origin thus obtaining the form of all extremals in the Schwarz Lemma for the
tetrablock. Some other extremals for the Lempert function and geodesics are
also given. The paper may be seen as a continuation of the results Abouhajar,
White and Young. The proofs rely on a necessary form of complex geodesics in
general domains which is also proven in the paper.Comment: 10 page
Green functions of the spectral ball and symmetrized polydisk
The Green function of the spectral ball is constant over the isospectral
varieties, is never less than the pullback of its counterpart on the
symmetrized polydisk, and is equal to it in the generic case where the pole is
a cyclic (non-derogatory) matrix. When the pole is derogatory, the inequality
is always strict, and the difference between the two functions depends on the
order of nilpotence of the strictly upper triangular blocks that appear in the
Jordan decomposition of the pole. In particular, the Green function of the
spectral ball is not symmetric in its arguments. Additionally, some estimates
are given for invariant functions in the symmetrized polydisc, e.g.
(infinitesimal versions of) the Carath\'eodory distance and the Green function,
that show that they are distinct in dimension greater or equal to .Comment: 12 page
On the Bergman representative coordinates
We study the set where the so-called Bergman representative coordinates (or
Bergman functions) form an immersion. We provide an estimate of the size of a
maximal geodesic ball with respect to the Bergman metric, contained in this
set. By concrete examples we show that these estimates are the best possible.Comment: 20 page
A remark on the dimension of the Bergman space of some Hartogs domains
Let D be a Hartogs domain of the form D={(z,w) \in CxC^N : |w| < e^{-u(z)}}
where u is a subharmonic function on C. We prove that the Bergman space of
holomorphic and square integrable functions on D is either trivial or infinite
dimensional.Comment: 12 page