4 problems

Let $H^{t_1,ots,t_s}$ be a $Z{3^s}$-linear generalized Hadamard code of length $3^t$ with $t1teq 2$ and $ts=0$. Suppose that $CH(t1,ots,ts)$ is the chain of equivalences associate…

Let $C_{a,b}$ be the generalized Hadamard full propelinear code associated to the orthogonal cocycle $\partial\phi_{(a,b)}$, where $\phi_{(a,b)}(g)=g^{(3^b+1)/2}$ for…

Let an $\operatorname{HFP}(2t,4_{\mathbf u})$-code be a Hadamard full propelinear code of the indicated type and length $4t$. HFP-code nonexistence conjecture. There do not exist…

A circulant Hadamard code of length $4t$ is the binary code formed by the rows of a normalized binary circulant Hadamard matrix and their complements. Circulant Hadamard code nonex…