Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A sharp upper bound for the $2$-torsion of class groups of
  multiquadratic fields   Let $K$ be a multiquadratic extension of $\mathbb{Q}$ and let
$\text{Cl}^{+}(K)$ be its narrow class group. Recently, the authors \cite{KP}
gave a bound for $|\text{Cl}^{+}(K)[2]|$ only in terms of the degree of $K$ and
the number of ramifying primes. In the present work we show that this bound is
sharp in a wide number of cases. Furthermore, we extend this to ray class
groups.

25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph