Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Lattice Universe from M-theory   A recent paper on the large-scale structure of the Universe presented
evidence for a rectangular three-dimensional lattice of galaxy superclusters
and voids, with lattice spacing ~120 Mpc and called for some ``hitherto unknown
process'' to explain it. Here we report that a rectangular three-dimensional
lattice of intersecting domain walls, with arbitrary spacing, emerges naturally
as a classical solution of M-theory.

14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph