Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nikishin systems are perfect. Case of unbounded and touching supports   K. Mahler introduced the concept of perfect systems in the theory of
simultaneous Hermite-Pad\'{e} approximation of analytic functions. Recently, we
proved that Nikishin systems, generated by measures with bounded support and
non-intersecting consecutive supports contained on the real line, are perfect.
Here, we prove that they are also perfect when the supports of the generating
measures are unbounded or touch at one point. As an application, we give a
version of Stieltjes' theorem in the context of simultaneous Hermite-Pad\'e
approximation.

11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
16
The categories of this paper are: stat
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat