Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Doubly transitive lines I: Higman pairs and roux   We study lines through the origin of finite-dimensional complex vector spaces
that enjoy a doubly transitive automorphism group. In doing so, we make
fundamental connections with both discrete geometry and algebraic
combinatorics. In particular, we show that doubly transitive lines are
necessarily optimal packings in complex projective space, and we introduce a
fruitful generalization of regular abelian distance-regular antipodal covers of
the complete graph.

28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
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The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat