Localization Operators On Discrete Modulation Spaces

TL;DR

This paper investigates time-frequency localization operators on discrete spaces, exploring their properties, boundedness, compactness, Schatten class membership, and their relation to other operator classes.

Contribution

It introduces modulation spaces on  and  , studies localization operators' properties, and connects them to paracommutators, paraproducts, and Fourier multipliers.

Findings

Localization operators are bounded and compact on modulation spaces.

These operators belong to the Schatten--von Neumann class.

Under certain conditions, they are paracommutators, paraproducts, and Fourier multipliers.

Abstract

In this paper, we study a class of pseudo-differential operators known as time-frequency localization operators on $\mathbb Z^n$, which depend on a symbol $\varsigma$ and two windows functions $g_1$ and $g_2$. We define the short-time Fourier transform on $ \mathbb Z^n \times \mathbb T^n $ and modulation spaces on $\mathbb Z^n$, and present some basic properties. Then, we use modulation spaces on $\mathbb Z^n \times \mathbb T^n$ as appropriate classes for symbols, and study the boundedness and compactness of the localization operators on modulation spaces on $\mathbb Z^n$. Then, we show that these operators are in the Schatten--von Neumann class. Also, we obtain the relation between the Landau--Pollak--Slepian type operator and the localization operator on $\mathbb Z^n$. Finally, under suitable conditions on the symbols, we prove that the localization operators are paracommutators, paraproducts and Fourier multipliers.