Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: About the spectra of a real nonnegative matrix and its signings   For a real matrix $M$, we denote by $sp(M)$ the spectrum of $M$ and by $\left
\vert M\right \vert $ its absolute value, that is the matrix obtained from $M$
by replacing each entry of $M$ by its absolute value. Let $A$ be a nonnegative
real matrix, we call a \emph{signing} of $A$ every real matrix $B$ such that
$\left \vert B\right \vert =A$. In this paper, we study the set of all signings
of $A$ such that $sp(B)=\alpha sp(A)$ where $\alpha$ is a complex unit number.
Our work generalizes some results obtained in [1, 5, 8].

7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph