Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the spread of outerplanar graphs   The spread of a graph is the difference between the largest and most negative
eigenvalue of its adjacency matrix. We show that for sufficiently large $n$,
the $n$-vertex outerplanar graph with maximum spread is a vertex joined to a
linear forest with $\Omega(n)$ edges. We conjecture that the extremal graph is
a vertex joined to a path on $n-1$ vertices.

1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph