Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A note on Bianchi-Don\`a's proof to the variance formula of von Neumann
  entropy   Bianchi and Don\`{a} [1] have recently reported a proof to the variance
formula of von Neumann entropy, which was conjectured in [2] and firstly proved
in [3]. The purpose of this short note is to show that, despite having a
different starting point, the subsequent calculations (omitted in [1]) leading
to the result are essentially the same as in [3].

15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin