4 problems

Fix integers $c\geq 3$, $d\geq 1$, and $t\geq 1$. For a perfect ideal, the codimension, deviation, and type are respectively $c$, $d$, and $t$; associate to the triplet the diagram…

Girã o, Snyder, and Popielarz's conjecture. There exists a constant $C>0$ such that every $(2k+1)$-connected tournament with minimum out-degree at least $Ck$ is $k$-linked.

Gir2o–Snyder–Popielarz conjecture. There exists a constant $C>0$ such that every $(2k+1)$-connected tournament with minimum out-degree at least $Ck$ is $k$-linked.

Let $R$ be a commutative local or graded ring, and let $M$ be a perfect module with a minimal free resolution of one of the formats … A module is in the BR-linkage class of a Buchs…