Some unexpected behaviors of operators with small time-frequency dispersion

نویسندگان

چکیده

We study the approximation properties of pseudo-differential operators with small time-frequency dispersion, meaning that their spreading functions are supported in a neighborhood origin. It is commonly assumed for such H, output Hf can differ only little from scalar multiple input f. However, we disprove this heuristic statement using theory superoscillations. This reveals some unexpected behaviors dispersion.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

some properties of fuzzy hilbert spaces and norm of operators

in this thesis, at first we investigate the bounded inverse theorem on fuzzy normed linear spaces and study the set of all compact operators on these spaces. then we introduce the notions of fuzzy boundedness and investigate a new norm operators and the relationship between continuity and boundedness. and, we show that the space of all fuzzy bounded operators is complete. finally, we define...

15 صفحه اول

Toeplitz operators with matrix-valued symbols and some (unexpected) applications

We discuss the eigenvalue distribution in the Weyl sense of general matrix-sequences associated to a symbol. As a specific case we consider Toeplitz sequences generated by matrix-valued (non Hermitian) bounded functions. We show that the canonical distribution can be proved under mild assumptions on the spectral range of the given symbol. Finally some applications are introduced and discussed.

متن کامل

Time Frequency Localization of Trigonometric Hermite Operators

In this paper, localization properties of trigonometric polynomial Hermite operators are discussed. In particular, time frequency uncertainty and operator norms are compared for the diierent types of fundamental interpolants which serve as scaling functions for a trigono-metric multiresolution analysis. x1. Introduction Recently, several diierent approaches to periodic multiresolution analyses ...

متن کامل

Frequency dispersion of small-amplitude capillary waves in viscous fluids.

This work presents a detailed study of the dispersion of capillary waves with small amplitude in viscous fluids using an analytically derived solution to the initial value problem of a small-amplitude capillary wave as well as direct numerical simulation. A rational parametrization for the dispersion of capillary waves in the underdamped regime is proposed, including predictions for the wave nu...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Journal of Pseudo-differential Operators and Applications

سال: 2023

ISSN: ['1662-999X', '1662-9981']

DOI: https://doi.org/10.1007/s11868-023-00513-x