On Extended Family of Fractional Sobolev Spaces Via Ultradistributions of Slow Growth

TL;DR

This paper introduces a new family of fractional Sobolev spaces based on ultradistributions of slow growth, generalizing classical Sobolev spaces with growth control and analyzing their structural properties.

Contribution

It defines and studies a novel class of fractional Sobolev spaces using ultradistributions, extending existing theories with new growth conditions and embedding results.

Findings

Established density and compact embedding results.

Extended classical Sobolev space theory with ultradistribution framework.

Analyzed extension domains within the new space family.

Abstract

This paper considers a new version of fractional Sobolev spaces $\widetilde{\mathcal{W}}_{\mathcal{U}}^{\beta,p}(\mathbb{C}^{n})$ defined using the concept of tempered ultradistributions with respect to the spaces of ultradifferentiable functions $\mathcal{U}(\mathbb{C})$. The space $\widetilde{\mathcal{W}}_{\mathcal{U}}^{\beta,p}(\mathbb{C}^{n})$ is a natural generalization of the classical Sobolev space with integer order, where some additional conditions of growth control have been introduced. We analyze some possible definitions and their roles in the structure theory. We prove some density and compact embedding results, investigating the possibility of the extension domains. Some of the results we present here are extensions of the existing ones with some additional conditions. The construction of the new family of fractional Sobolev space is considered within the framework of Fourier transform of ultradistributions of slow growth.