In algebra, a j-multiplicity is a generalization of a HilbertâÂÂSamuel multiplicity. For m-primary ideals, the two notions coincide.
Let be a local Noetherian ring of Krull dimension . Then the j-multiplicity of an ideal I is
where is the normalized coefficient of the degree d − 1 term in the Hilbert polynomial ; means the space of sections supported at .