Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The star-center of the quaternionic numerical range   In this paper we prove that the quaternionic numerical range is always
star-shaped and its star-center is given by the equivalence classes of the
star-center of the bild. We determine the star-center of the bild, and
consequently of the numerical range, by showing that the geometrical shape of
the upper part of the center is defined by two lines, tangents to the lower
bild.

35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con