104 research outputs found
Some properties of (C,E,P)-algebras : Overgneration and 0-order estimates
We give a new definition of the so-called overgenerated rings, which are the
usual tool used to define the asymptotic structure of a (C,E,P)-algebra,
written as a factor space M_{(A,E,P)}/N_{(I_{A},E,P)}. With this new definition
and in the particular case of E=C^{∞}, we show that a moderate element
i.e. in M_{(A,E,P)} is negligible if and only if it satisfies the
C⁰-order estimate for the ideal N_{(I_{A},E,P)}.Comment: Note, 5 page
Microlocal Asymptotic Analysis in Algebras of Generalized Functions
We introduce a new type of local and microlocal asymptotic analysis in
algebras of generalized functions, based on the presheaf properties of those
algebras and on the properties of their elements with respect to a regularizing
parameter. Contrary to the more classical frequential analysis based on the
Fourier transform, we can describe a singular asymptotic spectrum which has
good properties with respect to nonlinear operations. In this spirit we give
several examples of propagation of singularities through nonlinear operators.Comment: 21 page
Regular rapidly decreasing nonlinear generalized functions. Application to microlocal regularity
We present new types of regularity for nonlinear generalized functions, based
on the notion of regular growth with respect to the regularizing parameter of
Colombeau's simplified model. This generalizes the notion of G^{\infty
}-regularity introduced by M. Oberguggenberger. A key point is that these
regularities can be characterized, for compactly supported generalized
functions, by a property of their Fourier transform. This opens the door to
microanalysis of singularities of generalized functions, with respect to these
regularities. We present a complete study of this topic, including properties
of the Fourier transform (exchange and regularity theorems) and relationship
with classical theory, via suitable results of embeddings.Comment: Submitted to the Journal of Mathematical Analysis and Application
The partition bundle of type A_{N-1} (2, 0) theory
Six-dimensional (2, 0) theory can be defined on a large class of
six-manifolds endowed with some additional topological and geometric data (i.e.
an orientation, a spin structure, a conformal structure, and an R-symmetry
bundle with connection). We discuss the nature of the object that generalizes
the partition function of a more conventional quantum theory. This object takes
its values in a certain complex vector space, which fits together into the
total space of a complex vector bundle (the `partition bundle') as the data on
the six-manifold is varied in its infinite-dimensional parameter space. In this
context, an important role is played by the middle-dimensional intermediate
Jacobian of the six-manifold endowed with some additional data (i.e. a
symplectic structure, a quadratic form, and a complex structure). We define a
certain hermitian vector bundle over this finite-dimensional parameter space.
The partition bundle is then given by the pullback of the latter bundle by the
map from the parameter space related to the six-manifold to the parameter space
related to the intermediate Jacobian.Comment: 15 pages. Minor changes, added reference
Embeddings of ultradistributions and periodic hyperfunctions in Colombeau type algebras through sequence spaces
In a recent paper, we gave a topological description of Colombeau type
algebras introducing algebras of sequences with exponential weights. Embeddings
of Schwartz' spaces into the Colombeau algebra G are well known, but for
ultradistribution and periodic hyperfunction type spaces we give new
constructions. We show that the multiplication of regular enough functions
(smooth, ultradifferentiable or quasianalytic), embedded into corresponding
algebras, is the ordinary multiplication
La réforme de la formation des enseignants
La réforme de la formation des enseignants, voulue par le gouvernement actuel et appuyée sur une argumentation basée sur les recommandations européennes, nous semble pouvoir être analysée d'un triple point de vue : son inscription dans un processus d'évolution des dispositifs de formation des cadres de la fonction publique, marqué par une élévation du niveau de recrutement initial ; ses conséquences sur les institutions assurant la formation des enseignants ; les conséquences de son applicati..
Kernel Theorems in Spaces of Tempered Generalized Functions
In analogy to the classical isomorphism between
and , we show that a large class
of moderate linear mappings acting between the space
of Colombeau rapidly decreasing
generalized functions and the space of
temperate ones admits generalized integral representations, with kernels
belonging to . Furthermore, this result
contains the classical one in the sense of the generalized distribution
equality.Comment: 15 page
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