On the Steenrod operations in cyclic cohomology.
On the structure of sequentially Cohen-Macaulay bigraded modules
Let be a field and be the standard bigraded polynomial ring over . In this paper, we explicitly describe the structure of finitely generated bigraded “sequentially Cohen-Macaulay” -modules with respect to . Next, we give a characterization of sequentially Cohen-Macaulay modules with respect to in terms of local cohomology modules. Cohen-Macaulay modules that are sequentially Cohen-Macaulay with respect to are considered.
On the symmetric algebra of certain first syzygy modules
Let be a standard graded -algebra over a field . Then can be written as , where is a graded ideal of a polynomial ring . Assume that and is a strongly stable monomial ideal. We study the symmetric algebra of the first syzygy module of . When the minimal generators of are all of degree 2, the dimension of is calculated and a lower bound for its depth is obtained. Under suitable conditions, this lower bound is reached.
On the upper semicontinuity intersection defect.
On the vanishing of local cohomology modules.
On zero-dimensional subschemes of a complete intersections.
Opérations sur l'homologie cyclique des algèbres commutatives.
Optimal Betti numbers of forest ideals.
Orderings of monomial ideals
We study the set of monomial ideals in a polynomial ring as an ordered set, with the ordering given by reverse inclusion. We give a short proof of the fact that every antichain of monomial ideals is finite. Then we investigate ordinal invariants for the complexity of this ordered set. In particular, we give an interpretation of the height function in terms of the Hilbert-Samuel polynomial, and we compute bounds on the maximal order type.
Orientations and multiplicative structures of resolutions.
-adic monodromy of the universal deformation of a HW-cyclic Barsotti-Tate group.
p-adic semi-algebraic sets and cell decomposition.
Partial intersections and graded Betti numbers.
Pascal type properties of Betti numbers.
Perfekte Ideale und Vektormoduln über noetherschen Ringen
Pic is a contracted functor.
Planar graphs as minimal resolutions of trivariate monomial ideals.
Poincaré duality and commutative differential graded algebras
We prove that every commutative differential graded algebra whose cohomology is a simply-connected Poincaré duality algebra is quasi-isomorphic to one whose underlying algebra is simply-connected and satisfies Poincaré duality in the same dimension. This has applications in rational homotopy, giving Poincaré duality at the cochain level, which is of interest in particular in the study of configuration spaces and in string topology.
Pojective exterior Koszul homology and decomposititon of the Tor fonctor.
Polynomial Extensions and Excision for K1 .