Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A note on quantum entropy   Incremental information, as measured by the quantum entropy, is increasing
when two ensembles are united. This result was proved by Lieb and Ruskai, and
it is the foundation for the proof of strong subadditivity of quantum entropy.
We present a truly elementary proof of this fact in the context of the broader
family of matrix entropies introduced by Chen and Tropp.

30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat