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We introduce full diffeomorphism-invariant Colombeau algebras with added $\varepsilone$-dependence in the basic space. This unites the full and special settings of the theory into one single framework. Using locality conditions we find the…

Functional Analysis · Mathematics 2016-11-21 Eduard A. Nigsch , Michael Grosser

Colombeau generalized functions invariant under smooth (additive) one-parameter groups are characterized. This characterization is applied to generalized functions invariant under orthogonal groups of arbitrary signature, such as groups of…

Functional Analysis · Mathematics 2017-05-24 Hans Vernaeve

We develop a refined theory of microlocal analysis in the algebra ${\mathcal G}(\Omega)$ of Colombeau generalized functions. In our approach, the wave front is a set of generalized points in the cotangent bundle of $\Omega$, whereas in the…

Functional Analysis · Mathematics 2017-05-24 Hans Vernaeve

The concept of generalized functions taking values in a differentiable manifold is extended to a functorial theory. We establish several characterization results which allow a global intrinsic formulation both of the theory of…

Functional Analysis · Mathematics 2007-05-23 Michael Kunzinger , Roland Steinbauer , James A. Vickers

We study generalized group actions on differentiable manifolds in the Colombeau framework, extending previous work on flows of generalized vector fields and symmetry group analysis of generalized solutions. As an application, we analyze…

Functional Analysis · Mathematics 2007-06-12 Sanja Konjik , Michael Kunzinger

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…

Functional Analysis · Mathematics 2012-05-31 Michael Kunzinger , Eduard Nigsch

We investigate density of various subalgebras of regular generalized functions in the special Colombeau algebra of generalized functions.

Functional Analysis · Mathematics 2017-05-24 Hans Vernaeve

We illustrate the use of internal objects in the nonlinear theory of generalized functions by means of an application to microlocal analysis in Colombeau algebras.

Functional Analysis · Mathematics 2016-02-02 Hans Vernaeve

A proof that minimum uncertainty states of the simplest periodic quantum system exist in a state space that is represented by a Colombeau algebra of generalised functions but not in Hilbert space or in the space of Schwartz distributions is…

Mathematical Physics · Physics 2014-06-16 Ian G Fuss , Alexei Filinkov

It is often noted that many of the basic concepts of differential geometry, such as the definition of connection, are purely algebraic in nature. Here, we review and extend existing work on fully algebraic formulations of differential…

Differential Geometry · Mathematics 2025-02-03 Tobias Fritz

We extend the functional analytic approach to Colombeau-type spaces of nonlinear generalized functions in order to study algebras of tempered generalized functions. We obtain a definition of Fourier transform of nonlinear generalized…

Functional Analysis · Mathematics 2016-04-12 Eduard A. Nigsch

We study some properties of smoothing kernels and their local expression as they appear in the construction of Colombeau-type generalized function algebras which are diffeomorphism invariant.

Functional Analysis · Mathematics 2016-04-12 Eduard A. Nigsch

Modelling 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…

Functional Analysis · Mathematics 2010-07-12 Blagovest Damyanov

Summarizing basic facts from abstract topological modules over Colombeau generalized complex numbers we discuss duality of Colombeau algebras. In particular, we focus on generalized delta functionals and operator kernels as elements of dual…

Functional Analysis · Mathematics 2007-05-23 Claudia Garetto , Guenther Hoermann

The objective of this introduction to Colombeau algebras of generalized-functions (in which distributions can be freely multiplied) is to explain in elementary terms the essential concepts necessary for their application to basic non-linear…

Mathematical Physics · Physics 2008-11-19 Andre Gsponer

We present a construction of algebras of generalized functions of Colombeau-type which, instead of asymptotic estimates with respect to a regularization parameter, employs only topological estimates on certain spaces of kernels for its…

Functional Analysis · Mathematics 2017-04-27 Eduard A. Nigsch

We define a general notion of set of indices which, using concepts from pre-ordered sets theory, permits to unify the presentation of several Colombeau-type algebras of nonlinear generalized functions. In every set of indices it is possible…

Functional Analysis · Mathematics 2014-08-07 Paolo Giordano , Eduard Nigsch

In connection with the classical Schwartz kernel theorem, we show that in the framework of Colombeau generalized functions a large class of linear mappings admit integral kernels. To do this, we need to introduce news spaces of generalized…

Functional Analysis · Mathematics 2007-06-13 A. Delcroix

We introduce different notions of wave front set for the functionals in the dual of the Colombeau algebra $\Gc(\Om)$ providing a way to measure the $\G$ and the $\Ginf$- regularity in $\LL(\Gc(\Om),\wt{\C})$. For the smaller family of…

Analysis of PDEs · Mathematics 2007-05-23 Claudia Garetto

Based on a refinement of the notion of internal sets in Colombeau's theory, so-called strongly internal sets, we introduce the space of generalized smooth functions, a maximal extension of Colombeau generalized functions. Generalized smooth…

Functional Analysis · Mathematics 2016-09-15 Paolo Giordano , Michael Kunzinger , Hans Vernaeve