Adjointness properties for relative extensions of disk and sphere chain complexes

Marco Pérez

We study the subgroup $\mathcal{E}x{t}_{\mathcal{C}}^i(\mathcal{F};C,D)$ of $\mathcal{E}x{t}_{\mathcal{C}}^i(C,D)$ formed by those $i$-extensions of $C$ by $D$ in an Abelian category…