4 citations · 13 across the 16 of their papers we have counts for
6 papers · 1 filter
On superheight conditions for the affineness of open subsets
Holger Brenner
In this paper we consider the open complement U of a hypersurface Y=V(a) in an affine scheme X. We study the relations between the affineness of U, the intersection of Y with close…
How to rescue solid closure
Holger Brenner
We define a closure operation for ideals in a commutative ring which has all the good properties of solid closure (at least in the case of equal characteristic) but such that also…
A class of counter-examples to the hypersection problem based on forcing equations
Holger Brenner
We give a class of three-dimensional Stein spaces W together with a hypersurface H, such that the complement W-H is not Stein, but such that for every analytic surface S \subset W…
Tight closure and projective bundles
Holger Brenner
We formulate problems of tight closure theory in terms of projective bundles and subbundles. This provides a geometric interpretation of such problems and allows us to apply inters…
Lifting chains of prime ideals
Holger Brenner
We give an elementary proof that for a ring homomorphism A -> B, satisfying the property that every ideal in A is contracted from B, the following property holds: for every chain o…
Tight closure and plus closure for cones over elliptic curves
Holger Brenner
We characterize the tight closure of graded primary ideals in a homogeneous coordinate ring over an elliptic curve by numerical conditions and we show that it is in positive charac…