Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Maximality of Seidel matrices and switching roots of graphs   In this paper, we discuss maximality of Seidel matrices with a fixed largest
eigenvalue. We present a classification of maximal Seidel matrices of largest
eigenvalue $3$, which gives a classification of maximal equiangular lines in a
Euclidean space with angle $\arccos1/3$. Motivated by the maximality of the
exceptional root system $E_8$, we define strong maximality of a Seidel matrix,
and show that every Seidel matrix achieving the absolute bound is strongly
maximal.

7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol