On self-dual and LCD double circulant and double negacirculant codes over ${\mathbb{F}}_q+u{\mathbb{F}}_q$

Minjia Shi, Hongwei Zhu, Liqin Qian +2

Double circulant codes of length $2n$ over the semilocal ring $R={\mathbb{F}}_q+u{\mathbb{F}}_q,u^2=u,$ are studied when $q$ is an odd prime power, and $-1$ is a square in $\mat…