English
Related papers

Related papers: Fourier frames for singular measures and pure type…

200 papers

Let $\mu$ be a Borel probability measure with compact support. We consider exponential type orthonormal bases, Riesz bases and frames in $L^2(\mu)$. We show that if $L^2(\mu)$ admits an exponential frame, then $\mu$ must be of pure type. We…

Functional Analysis · Mathematics 2013-03-04 Xing-Gang He , Chun-Kit Lai , Ka-Sing Lau

It is known that if a finite Borel measure $\mu$ on $[0,1)$ possesses a frame of exponential functions for $L^{2}(\mu)$, then $\mu$ is of pure type. In this paper, we prove the existence of a class of finite Borel measures $\mu$ on $[0,1)$…

Functional Analysis · Mathematics 2024-01-11 Chad Berner

Let $\mu$ be a compactly supported absolutely continuous probability measure on ${\Bbb R}^n$, we show that $\mu$ admits Fourier frames if and only if its Radon-Nikodym derivative is upper and lower bounded almost everywhere on its support.…

Functional Analysis · Mathematics 2011-10-31 Chun-kit Lai

For every frame spectral measure $ \mu $, there exists a discrete measure $ \nu $ as a frame measure. Since if $ \mu $ is not a frame spectral measure, then there is not any general statement about the existence of frame measures $ \nu $…

Functional Analysis · Mathematics 2019-05-21 Fariba Zeinal Zadeh Farhadi , Mohammad Sadegh Asgari , Mohammad Reza Mardanbeigi

A finite Borel measure $\mu$ in ${\mathbb R}^d$ is called a frame-spectral measure if it admits an exponential frame (or Fourier frame) for $L^2(\mu)$. It has been conjectured that a frame-spectral measure must be translationally absolutely…

Functional Analysis · Mathematics 2017-07-14 Xiaoye Fu , Chun-Kit Lai

In this paper we show that the surface measure on the boundary of a convex body of everywhere positive Gaussian curvature does not admit a Fourier frame. This answers a question proposed by Lev and provides the first example of a uniformly…

Classical Analysis and ODEs · Mathematics 2019-05-21 Alex Iosevich , Chun-Kit Lai , Bochen Liu , Emmett Wyman

We examine Fourier frames and, more generally, frame measures for different probability measures. We prove that if a measure has an associated frame measure, then it must have a certain uniformity in the sense that the weight is distributed…

Functional Analysis · Mathematics 2021-07-20 Dorin Ervin Dutkay , Chun-Kit Lai

For every $0<s\leq 1$ we construct $s$-dimensional Salem measures in the unit interval that do not admit any Fourier frame. Our examples are generic for each $s$, including all existing types of Salem measures in the literature: random…

Classical Analysis and ODEs · Mathematics 2025-06-03 Longhui Li , Bochen Liu

We generalize the compatible tower condition given by Strichartz to the almost-Parseval-frame tower and show that non-trivial examples of almost-Parseval-frame tower exist. By doing so, we demonstrate the first singular fractal measure…

Functional Analysis · Mathematics 2018-05-03 Chun-Kit Lai , Yang Wang

Given discrete subsets $\Lambda_j\subset {\Bbb R}^d$, $j=1,...,q$, consider the set of windowed exponentials $\bigcup_{j=1}^{q}\{g_j(x)e^{2\pi i <\lambda,x>}: \lambda\in\Lambda_j\}$ on $L^2(\Omega)$. We show that a necessary and sufficient…

Functional Analysis · Mathematics 2016-05-03 Jean-Pierre Gabardo , Chun-Kit Lai

J.C.Lagarias (2000) conjectured that if $\mu$ is a complex measure on p-dimensional Euclidean space with a uniformly discrete support and its spectrum (Fourier transform) is also a measure with a uniformly discrete support, then the support…

Classical Analysis and ODEs · Mathematics 2015-03-03 Sergii Yu. Favorov

Let $Q$ be a fundamental domain of some full-rank lattice in ${\Bbb R}^d$ and let $\mu$ and $\nu$ be two positive Borel measures on ${\Bbb R}^d$ such that the convolution $\mu\ast\nu$ is a multiple of $\chi_Q$. We consider the problem as to…

Functional Analysis · Mathematics 2016-05-03 Jean-Pierre Gabardo , Chun-Kit Lai

For every set $S$ of finite measure in $\mathbb{R}$ we construct a discrete set of real frequencies $\Lambda$ such that the exponential system $\{\exp(i\lambda t),\lambda\in\Lambda\}$ is a frame in $L^2(S)$

Classical Analysis and ODEs · Mathematics 2014-10-22 Shahaf Nitzan , Alexander Olevskii , Alexander Ulanovskii

This paper relates to the Fourier decay properties of images of self-similar measures $\mu$ on $\mathbb{R}^k$ under nonlinear smooth maps $f \colon \mathbb{R}^k \to \mathbb{R}$. For example, we prove that if the linear parts of the…

Dynamical Systems · Mathematics 2025-03-11 Amlan Banaji , Han Yu

For multi-variable finite measure spaces, we present in this paper a new framework for non-orthogonal $L^2$ Fourier expansions. Our results hold for probability measures $\mu$ with finite support in $\mathbb{R}^d$ that satisfy a certain…

Functional Analysis · Mathematics 2024-02-27 Chad Berner , John E. Herr , Palle E. T. Jorgensen , Eric S. Weber

A classical result of Arne Beurling states that the Fourier transform of a nonzero complex Borel measure $\mu$ on the real line cannot vanish on a set of positive Lebesgue measure if $\mu$ has certain decay. We prove a several variable…

Functional Analysis · Mathematics 2023-06-01 Santanu Debnath , Suparna Sen

For a probability measure $\mu$ on SL d (R), we consider the Furstenberg stationary measure on the space of flags. Under general non-degeneracy conditions, if $\mu$ is discrete and if g log g d$\mu$(g) < +$\infty$, then the measure $\nu$ is…

Dynamical Systems · Mathematics 2021-12-30 Francois Ledrappier , Pablo Lessa

Let $\mu$ be a measure on the Euclidean space $\R^d$ of unbounded total variation that is positive or translation bounded and has a pure point Fourier transform in the sense of distributions $\hat\mu$. We prove that the measure $\nu$ with…

Functional Analysis · Mathematics 2025-03-26 Peter Boyvalenkov , Sergii Yu. Favorov

In recent papers a number of authors have considered Borel probability measures $\mu$ in $\br^d$ such that the Hilbert space $L^2(\mu)$ has a Fourier basis (orthogonal) of complex exponentials. If $\mu$ satisfies this property, the set of…

Functional Analysis · Mathematics 2011-02-04 Dorin Ervin Dutkay , Palle E. T. Jorgensen

It is known that a small spherical cap (rigorously its surface measure) admits Fourier frames, while the whole sphere does not. In this paper, we prove more general results. Consequences indclude that a small spherical cap in $\mathbb{R}^d$…

Classical Analysis and ODEs · Mathematics 2025-07-09 Xinyu Chen , Bochen Liu
‹ Prev 1 2 3 10 Next ›