Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Spectral Problem and Algebras Associated with Extended Dynkin Graphs   The Spectral Problem is to describe possible spectra $\sigma (A_j)$ for an
irreducible $n$-tuple of Hermitian operators s.t. $A_1+...+A_n$ is a scalar
operator. In case when $m_j= | \sigma (A_j)|$ are finite and a rooted tree
${\rm T}_{m_1,..., m_n}$ with $n$ branches of lengths $m_1, ..., m_n$ is a
Dynkin graph the explicit answer to the Spectral Problem was given recently by
S. A. Kruglyak, S. V. Popovych, and Yu. S. Samo\v\i{}lenko. In present work the
solution of the Spectral Problem for all star-shaped simply laced extended
Dynkin graphs, i.e. when $(m_1, ..., m_n) \in \{(2,2,2,2), (3,3,3), (4,4,2)$,
$(6,3,2)\}$ is presented.

11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc