Adjoint Ideals along Closed Subvarieties of Higher Codimension

Lifting Problem in Codimension 2 and Initial Ideals

APPROXIMATE IDENTITY IN CLOSED CODIMENSION ONE IDEALS OF SEMIGROUP ALGEBRAS

Let S be a locally compact topological foundation semigroup with identity and Ma(S) be its semigroup algebra. In this paper, we give necessary and sufficient conditions to have abounded approximate identity in closed codimension one ideals of the semigroup algebra $M_a(S)$ of a locally compact topological foundationsemigroup with identity.

Ordinary Subvarieties of Codimension One

In this paper we extend the properties of ordinary points of curves [10] to ordinary closed points of one-dimensional affine reduced schemes and then to ordinary subvarieties of codimension one.

On a Special Class of Smooth Codimension Two Subvarieties

We work on an algebraically closed field of characteristic zero. By Lefschetz’s theorem, a smooth codimension two subvariety X ⊂ P, n ≥ 4, which is not a complete intersection, lying on a hypersurface Σ, verifies dim(X ∩ Sing(Σ)) ≥ n− 4. In this paper we deal with a situation in which the singular locus of Σ is as large as can be, but, at the same time, the simplest possible: we assume Σ is an ...

On the Number of Compatibly Frobenius Split Subvarieties, Prime F -ideals, and Log Canonical Centers

Let X be a projective Frobenius split variety over an algebraically closed field with splitting θ : F∗OX → OX . In this paper we give a sharp bound on the number of subvarieties of X compatibly split by θ. In particular, suppose L is a sufficiently ample line bundle on X (for example, if L induces a projectively normal embedding) with n = dimH(X,L ). We show that the number of d-dimensional irr...