Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Improved sphere packing lower bounds from Hurwitz lattices   In this paper we prove an asymptotic lower bound for the sphere packing
density in dimensions divisible by four. This asymptotic lower bound improves
on previous asymptotic bounds by a constant factor and improves not just lower
bounds for the sphere packing density, but also for the lattice sphere packing
density and, in fact, the Hurwitz lattice sphere packing density.

1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn