Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Infinite families of regular expanders of arbitrary constant degree
  obtained via the modified zig-zag product   We generalize the zig-zag product construction to produce infinite families
of regular graphs of any constant degree. We analyze the second largest
eigenvalue of this new zig-zag product to show that the modified zig-zag
product of good expanders is again a good expander (yet not Ramanujan).

12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph