Gluing Cohen-Macaulay modules with applications to quasihomogeneous complete intersections with isolated singularities.
Gonality and Clifford index for real algebraic curves.
Let X be a smooth connected projective curve of genus g defined over R. Here we give bounds for the real gonality of X in terms of the complex gonality of X.
Gonality for stable curves and their maps with a smooth curve as their target
Here we study the deformation theory of some maps f: X → ℙr , r = 1, 2, where X is a nodal curve and f|T is not constant for every irreducible component T of X. For r = 1 we show that the “stratification by gonality” for any subset of [...] with fixed topological type behaves like the stratification by gonality of M g.
Good and Stable Reduction of Abelian Varieties.
Good Embedding Dimensions for Gorenstein Singularities.
Good moduli spaces for Artin stacks
We develop the theory of associating moduli spaces with nice geometric properties to arbitrary Artin stacks generalizing Mumford’s geometric invariant theory and tame stacks.
Good properties of algebras of invariants and defect of linear representations.
Good reduction of affinoids on the Lubin-Tate tower.
Good reduction of elliptic curves in abelian extensions.
Gorenstein liaison of some curves in P4.
Despite the recent advances made in Gorenstein liaison, there are still many open questions for the theory in codimension ≥ 3. In particular we consider the following question: given two curves in Pn with isomorphic deficiency modules (up to shift), can they be evenly Gorenstein linked? The answer for this is yes for curves in P3, due to Rao, but for higher codimension the answer is not known. This paper will look at large classes of curves in P4 with isomorphic deficiency modules and show that...
Gorenstein points in .
Gorenstein Rings and Modules with High Numbers of Generators.
Graded Betti numbers of some embedded rational n-folds.
Graded quaternion symbol equivalence of function fields
We present criteria for a pair of maps to constitute a quaternion-symbol equivalence (or a Hilbert-symbol equivalence if we deal with global function fields) expressed in terms of vanishing of the Clifford invariant. In principle, we prove that a local condition of a quaternion-symbol equivalence can be transcribed from the Brauer group to the Brauer-Wall group.
Gradient horizontal de fonctions polynomiales
Nous étudions les trajectoires du gradient sous-riemannien (appellé horizontal) de fonctions polynômes. Dans ce cadre l’inégalité de Łojasiewicz n’est pas valide et une trajectoire du gradient horizontal peut être de longueur infinie, et peut même s’accumuler sur une courbe fermée. Nous montrons que ces comportement sont exceptionnels ; et que, pour une fonction générique les trajectoires de son gradient horizontal ont des propriétés similaires au cas du gradient riemannien. Pour obtenir la finitude...
Graph theoretic techniques in algebraic geometry II: construction of singular complex surfaces of the rational cohomology type of CP2.
Grassmann defective surfaces
A projective variety is -defective if the Grassmannian of lines contained in the span of independent points on has dimension less than the expected one. In the present paper, which is inspired by classical work of Alessandro Terracini, we prove a criterion of -defectivity for algebraic surfaces and we discuss its applications to Veronese embeddings and to rational normal scrolls.
Grassmann duality for -modules
Grauert's theorem for subanalytic open sets in real analytic manifolds
By an open neighbourhood in ℂⁿ of an open subset Ω of ℝⁿ we mean an open subset Ω' of ℂⁿ such that ℝⁿ ∩ Ω' = Ω. A well known result of H. Grauert implies that any open subset of ℝⁿ admits a fundamental system of Stein open neighbourhoods in ℂⁿ. Another way to state this property is to say that each open subset of ℝⁿ is Stein. We shall prove a similar result in the subanalytic category: every subanalytic open subset in a paracompact real analytic manifold M admits a fundamental system of subanalytic...
Greatest common divisors of , in positive characteristic and rational points on curves over finite fields
In our previous work we proved a bound for the , for -units of a function field in characteristic zero. This generalized an analogous bound holding over number fields, proved in [3]. As pointed out by Silverman, the exact analogue does not work for function fields in positive characteristic. In the present work, we investigate possible extensions in that direction; it turns out that under suitable assumptions some of the results still hold. For instance we prove Theorems 2 and 3 below, from...