Let be a semidualizing module over a commutative ring. We first investigate the properties of -dual, -torsionless and -reflexive modules. Then we characterize some rings such as coherent rings, -coherent rings and FP-injectivity of using -dual, -torsionless and -reflexive properties of some special modules.
Let X be a separated scheme of finite type on a field k, the characteristic of k being assumed not equal to 2. We construct a duality for complexes of sheaves of Ox modules with maps differential operators of order ≤ 1. This theory is an extension of the theory built by R. Hartshorne for complexes with linear maps.
Un survol des conjectures de Drinfeld, Beilinson, Gaitsgory et al. et de résultats de Gaitsgory sur la correspondance de Langlands quantique.
The paper establishes a duality between a category of free subreducts of affine spaces and a corresponding category of generalized hypercubes with constants. This duality yields many others, in particular a duality between the category of (finitely generated) free barycentric algebras (simplices of real affine spaces) and a corresponding category of hypercubes with constants.
In the classical Witt theory over a field F, the study of quadratic forms begins with two simple invariants: the dimension of a form modulo 2, called the dimension index and denoted e⁰: W(F) → ℤ/2, and the discriminant e¹ with values in k₁(F) = F*/F*², which behaves well on the fundamental ideal I(F)= ker(e⁰). Here a more sophisticated situation is considered, of quadratic forms over a scheme and, more generally, over an exact category with duality. Our purposes are: ...