Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Complete classification of $(\delta+\alpha u^2)$-constacyclic codes over
  $\mathbb{F}_{2^m}[u]/\langle u^4\rangle$ of oddly even length   Let $\mathbb{F}_{2^m}$ be a finite field of cardinality $2^m$,
$R=\mathbb{F}_{2^m}[u]/\langle u^4\rangle)$ and $n$ is an odd positive integer.
For any $\delta,\alpha\in \mathbb{F}_{2^m}^{\times}$, ideals of the ring
$R[x]/\langle x^{2n}-(\delta+\alpha u^2)\rangle$ are identified as
$(\delta+\alpha u^2)$-constacyclic codes of length $2n$ over $R$. In this
paper, an explicit representation and enumeration for all distinct
$(\delta+\alpha u^2)$-constacyclic codes of length $2n$ over $R$ are presented.

24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph