Du Bois singularity
In algebraic geometry, Du Bois singularities are singularities of complex varieties studied by Du Bois.
Schwede gave the following characterisation of Du Bois singularities. Suppose that is a reduced closed subscheme of a smooth scheme.
Take a log resolution of in that is an isomorphism outside, and let be the reduced preimage of in. Then has Du Bois singularities if and only if the induced map is a quasi-isomorphism.