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Faisceaux analytiques semi-cohérents

Jean Merrien (1980)

Annales de l'institut Fourier

Nous définissons deux notions nouvelles en géométrie analytique réelle, celle de fonction Nash-analytique et celle de faisceau semi-cohérent. Avec ces notions, nous obtenons des théorèmes de cohérence analogues à ceux du cas complexe (théorème de cohérence d’Oka, théorème de l’image directe, cohérence d’un ensemble analytique complexe).

Families of functions dominated by distributions of C -classes of mappings

Goo Ishikawa (1983)

Annales de l'institut Fourier

A subsheaf of the sheaf Ω of germs C functions over an open subset Ω of R n is called a sheaf of sub C function. Comparing with the investigations of sheaves of ideals of Ω , we study the finite presentability of certain sheaves of sub C -rings. Especially we treat the sheaf defined by the distribution of Mather’s 𝒞 -classes of a C mapping.

Fano manifolds of degree ten and EPW sextics

Atanas Iliev, Laurent Manivel (2011)

Annales scientifiques de l'École Normale Supérieure

O’Grady showed that certain special sextics in 5 called EPW sextics admit smooth double covers with a holomorphic symplectic structure. We propose another perspective on these symplectic manifolds, by showing that they can be constructed from the Hilbert schemes of conics on Fano fourfolds of degree ten. As applications, we construct families of Lagrangian surfaces in these symplectic fourfolds, and related integrable systems whose fibers are intermediate Jacobians.

Felix Klein's paper on real flexes vindicated

Felice Ronga (1998)

Banach Center Publications

In a paper written in 1876 [4], Felix Klein gave a formula relating the number of real flexes of a generic real plane projective curve to the number of real bitangents at non-real points and the degree, which shows in particular that the number of real flexes cannot exceed one third of the total number of flexes. We show that Klein's arguments can be made rigorous using a little of the theory of singularities of maps, justifying in particular his resort to explicit examples.

Fenomeni di concentrazione per energie di tipo Ginzburg-Landau

Ilaria Fragalà (2005)

Bollettino dell'Unione Matematica Italiana

Si discute il comportamento asintotico di energie di tipo Ginzburg-Landau, per funzioni da R n + k in R k , e sotto l'ipotesi che l'esponente di crescita p sia strettamente maggiore di k . In particolare, si illustra un risultato di compattezza e di Γ -convergenza, rispetto a una opportuna topologia sui Jacobiani, visti come correnti n -dimensionali. L'energia limite è definita sulla classe degli n -bordi interi M , e la sua densità dipende localmente dalla molteplicità di M tramite una famiglia di costanti di...

Feuilletage canonique sur le fibré de Weil

Basile Guy Richard Bossoto (2010)

Colloquium Mathematicae

Let be M a smooth manifold, A a local algebra and M A a manifold of infinitely near points on M of kind A. We build the canonical foliation on M A and we show that the canonical foliation on the tangent bundle TM is the foliation defined by its canonical field.

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