Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Balancedly splittable orthogonal designs and equiangular tight frames   The concept of balancedly splittable orthogonal designs is introduced along
with a recursive construction. As an application, equiangular tight frames over
the real, complex, and quaternions meeting the Delsarte-Goethals-Seidel upper
bound is obtained.

21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin