Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Second-Order Converse Bound for the Multiple-Access Channel via
  Wringing Dependence   A new converse bound is presented for the two-user multiple-access channel
under the average probability of error constraint. This bound shows that for
most channels of interest, the second-order coding rate -- that is, the
difference between the best achievable rates and the asymptotic capacity region
as a function of blocklength $n$ with fixed probability of error -- is
$O(1/\sqrt{n})$ bits per channel use. The principal tool behind this converse
proof is a new measure of dependence between two random variables called
wringing dependence, as it is inspired by Ahlswede's wringing technique. The
$O(1/\sqrt{n})$ gap is shown to hold for any channel satisfying certain
regularity conditions, which includes all discrete-memoryless channels and the
Gaussian multiple-access channel. Exact upper bounds as a function of the
probability of error are proved for the coefficient in the $O(1/\sqrt{n})$
term, although for most channels they do not match existing achievable bounds.

17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics