Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A note on "Algebraic approach to Casimir force between two $\delta$-like
  potentials" (K. Ziemian, Ann. Henri Poincar\'e, Online First, 2021)   We comment on the recent work [1], and on its relations with our papers [2,3]
cited therein. In particular we show that, contrarily to what stated in [1],
the Casimir energy density determined therein in the case of a single
delta-like singularity coincides with the energy density obtained previously in
our paper [2] using a different approach.

21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat