Let X be a smooth complex variety and Y a proper closed subscheme of X. The log canonical threshold (lct) of the pair (X,Y) is a positive rational number which measures the singularities of Y, and the study of this quantity is an important topic in birational geometry with connections to the minimal model program. In positive characteristic, one instead typically studies the F-pure threshold (fpt) of a pair. When R is a F-finite ring and I an ideal of R, the quantity fpt(R,I) measures how far the ring R/I is from being strongly F-regular.

In 2014, Demailly and Phan defined an invariant of a pair (R, I) in terms of certain mixed multiplicities of the ideal I and showed that this invariant is a lower bound on the log canonical threshold. In the case of a pair (R, I), where R is a polynomial ring and I is an ideal generated by a homogeneous regular sequence, we classify exactly when the log canonical threshold is equal to Demailly and Phan's invariant.