منابع مشابه
Ample Sheaves and Ample Families
1 Ample Sheaves Let X be a scheme and L an invertible sheaf. Given a global section f ∈ Γ(X,L ) the set Xf = {x ∈ X | germxf / ∈ mxLx} is open (MOS,Lemma 29). The inclusion Xf −→ X is affine (RAS,Lemma 6) and in particular if X is an affine scheme then Xf is itself affine. Given a sequence of global sections f1, . . . , fn the open sets Xfi cover X if and only if the fi generate L (MOS,Lemma 32...
متن کاملAMPLE SUBVARIETIES AND q-AMPLE DIVISORS
We introduce a notion of ampleness for subschemes of any codimension using the theory of q-ample line bundles. We also investigate certain geometric properties satisfied by ample subvarieties, e.g. the Lefschetz hyperplane theorems and numerical positivity. Using these properties, we also construct a counterexample to the converse of the Andreotti-Grauert vanishing theorem.
متن کاملAMPLE AND LEFT AMPLE SEMIGROUPS Extended
When E is actually the set of all idempotents of S, we drop the phrase “with respect to” and refer simply to the left or right ample condition. Recall that a partial permutation of a nonempty set X is a bijection σ : Y → Z for some subsets Y, Z of X, and that the set of all such partial permutations (denoted by IX) is a monoid under the usual composition of partial functions. Note that if σ : Y...
متن کاملAmple dividing
We construct a stable one-based, trivial theory with a reduct which is not trivial. This answers a question of John B. Goode. Using this, we construct a stable theory which is n-ample for all natural numbers n, and does not interpret an infinite group.
متن کاملAmple Hierarchy
The ample hierarchy of geometries of stables theories is strict. We generalise the construction of the free pseudospace to higher dimensions and show that the n-dimensional free pseudospace is ω-stable n-ample yet not (n+ 1)-ample. In particular, the free pseudospace is not 3-ample. A thorough study of forking is conducted and an explicit description of canonical bases is exhibited.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Fundamenta Mathematicae
سال: 2019
ISSN: 0016-2736,1730-6329
DOI: 10.4064/fm606-10-2018