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Kernel theorems in spaces of generalized functions

Antoine Delcroix (2010)

Banach Center Publications

In analogy to the classical isomorphism between ((ℝⁿ), ' ( m ) ) and ' ( m + n ) (resp. ( ( ) , ' ( m ) ) and ' ( m + n ) ), we show that a large class of moderate linear mappings acting between the space C ( ) of compactly supported generalized functions and (ℝⁿ) of generalized functions (resp. the space ( ) of Colombeau rapidly decreasing generalized functions and the space τ ( ) of temperate ones) admits generalized integral representations, with kernels belonging to specific regular subspaces of ( m + n ) (resp. τ ( m + n ) ). The main novelty is to use accelerated...

Manifold-valued generalized functions in full Colombeau spaces

Michael Kunzinger, Eduard Nigsch (2011)

Commentationes Mathematicae Universitatis Carolinae

We introduce the notion of generalized function taking values in a smooth manifold into the setting of full Colombeau algebras. After deriving a number of characterization results we also introduce a corresponding concept of generalized vector bundle homomorphisms and, based on this, provide a definition of tangent map for such generalized functions.

On a nonlinear Peetre's theorem in full Colombeau algebras

E. A. Nigsch (2017)

Commentationes Mathematicae Universitatis Carolinae

We adapt a nonlinear version of Peetre's theorem on local operators in order to investigate representatives of nonlinear generalized functions occurring in the theory of full Colombeau algebras.

On Generalized Models and Singular Products of Distributions in Colombeau Algebra G(R)

Damyanov, Blagovest P. (2013)

Mathematica Balkanica New Series

MSC 2010: 46F30, 46F10Modelling of singularities given by discontinuous functions or distributions by means of generalized functions has proved useful in many problems posed by physical phenomena. We introduce in a systematic way generalized functions of Colombeau that model such singularities. Moreover, we evaluate some products of singularity-modelling generalized functions whenever the result admits an associated distribution.

On hypoellipticity in 𝒢 .

Nedeljkov, M., Pilipović, S. (2002)

Bulletin. Classe des Sciences Mathématiques et Naturelles. Sciences Mathématiques

On hypoellipticity in g

M. Nedeljkov, S. Pilipović (2002)

Bulletin, Classe des Sciences Mathématiques et Naturelles, Sciences mathématiques

On introduction of two diffeomorphism invariant Colombeau algebras

Jiří Jelínek (2004)

Commentationes Mathematicae Universitatis Carolinae

Equivalent definitions of two diffeomorphism invariant Colombeau algebras introduced in [7] and [5] (Grosser et al.) are listed and some new equivalent definitions are presented. The paper can be treated as tools for proving in [8] the equality of both algebras.

On systems of linear algebraic equations in the Colombeau algebra

Jan Ligęza, Milan Tvrdý (1999)

Mathematica Bohemica

From the fact that the unique solution of a homogeneous linear algebraic system is the trivial one we can obtain the existence of a solution of the nonhomogeneous system. Coefficients of the systems considered are elements of the Colombeau algebra ¯ of generalized real numbers. It is worth mentioning that the algebra ¯ is not a field.

On the sign of Colombeau functions and applications to conservation laws

Jiří Jelínek, Dalibor Pražák (2009)

Commentationes Mathematicae Universitatis Carolinae

A generalized concept of sign is introduced in the context of Colombeau algebras. It extends the sign of the point-value in the case of sufficiently regular functions. This concept of generalized sign is then used to characterize the entropy condition for discontinuous solutions of scalar conservation laws.

Recent progress in special Colombeau algebras: geometry, topology, and algebra

M. Kunzinger (2010)

Banach Center Publications

Over the past few years there has been considerable progress in the structural understanding of special Colombeau algebras. We present some of the main trends in this development: non-smooth differential geometry, locally convex theory of modules over the ring of generalized numbers, and algebraic aspects of Colombeau theory. Some open problems are given and directions of further research are outlined.

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