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The Fourier transform is typically seen as closely related to the additive group of real numbers, its characters and its Haar measure. In this paper, we propose an alternative viewpoint; the Fourier transform can be uniquely characterized…

Functional Analysis · Mathematics 2024-06-11 Cameron L. Williams , Bernhard G. Bodmann , Donald J. Kouri

Positive-definite kernel functions are fundamental elements of kernel methods and Gaussian processes. A well-known construction of such functions comes from Bochner's characterization, which connects a positive-definite function with a…

Machine Learning · Statistics 2016-10-28 Jie Chen , Dehua Cheng , Yan Liu

We find a formula that relates the Fourier transform of a radial function on $\mathbf{R}^n$ with the Fourier transform of the same function defined on $\mathbf{R}^{n+2}$. This formula enables one to explicitly calculate the Fourier…

Classical Analysis and ODEs · Mathematics 2013-02-19 Loukas Grafakos , Gerald Teschl

The Fourier transformation is an effective and efficient operation of Gaussianization at the one-point level. Using a set of N-body simulation data, we verified that the one-point distribution functions of the dark matter momentum…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-05 Ming Li , Jun Pan , Pengjie Zhang , Jie Wang , Longlong Feng , Liang Gao , Xi Kang , Guoliang Li , Weipeng Lin , Haihui Wang

In this note we compare two measures of the complexity of a class $\mathcal F$ of Boolean functions studied in (unconditional) pseudorandomness: $\mathcal F$'s ability to distinguish between biased and uniform coins (the coin problem), and…

Computational Complexity · Computer Science 2020-09-01 Rohit Agrawal

Fourier-transformable Radon measures are called doubly sparse when both the measure and its transform are pure point measures with sparse support. Their structure is reasonably well understood in Euclidean space, based on the use of…

Metric Geometry · Mathematics 2020-05-06 Michael Baake , Nicolae Strungaru , Venta Terauds

We use a noncommutative generalization of Fourier analysis to define a broad class of pseudo-probability representations, which includes the known bosonic and discrete Wigner functions. We characterize the groups of quantum unitary…

Mathematical Physics · Physics 2020-05-19 Sang Jun Park , Cedric Beny , Hun Hee Lee

Let $\mu$ be a probability measure on $\mathbb{R}$. We give conditions on the Fourier transform of its density for functionals of the form $H(a)=\int_{\mathbb{R}^n}h(\langle a,x\rangle)\mu^n(dx)$ to be Schur monotone. As applications, we…

Probability · Mathematics 2025-04-09 Andreas Malliaris

We introduce a class of integral theorems based on cyclic functions and Riemann sums approximating integrals. The Fourier integral theorem, derived as a combination of a transform and inverse transform, arises as a special case. The…

Computation · Statistics 2022-03-22 Nhat Ho , Stephen G. Walker

Fourier series multiscale method, a concise and efficient analytical approach for multiscale computation, will be developed out of this series of papers. The second paper is concerned with simultaneous approximation to functions and their…

Numerical Analysis · Mathematics 2022-08-09 Weiming Sun , Zimao Zhang

A version of the Dirac equation is derived from first principles using a combination of quaternions and multivariate 4-vectors. The nilpotent form of the operators used allows us to derive explicit expressions for the wavefunctions of free…

Quantum Physics · Physics 2007-05-23 Peter Rowlands , John P. Cullerne

A function of positive type can be defined as a positive functional on a convolution algebra of a locally compact group. In the case where the group is abelian, by Bochner's theorem a function of positive type is, up to normalization, the…

Mathematical Physics · Physics 2014-11-06 Paolo Aniello

This paper is a companion paper to [G4], where sharp estimates are proven for Fourier transforms of compactly supported functions built out of two-dimensional real-analytic functions. The theorems of [G4] are stated in a rather general…

Classical Analysis and ODEs · Mathematics 2016-05-27 Michael Greenblatt

This note presents a rigorous introduction to a selection of distributions along with their Fourier transforms, which are commonly encountered in signal processing and, in particular, magnetic resonance imaging (MRI). In contrast to many…

Functional Analysis · Mathematics 2025-06-24 Kaibo Tang

A wide class of physical distributions appears to follow the q-Gaussian form, which plays the role of attractor according to a Central Limit Theorem generalized in the presence of specific correlations between the relevant random variables.…

Mathematical Physics · Physics 2015-03-17 M. Jauregui , C. Tsallis

The random Fourier features (RFFs) method is a powerful and popular technique in kernel approximation for scalability of kernel methods. The theoretical foundation of RFFs is based on the Bochner theorem that relates symmetric, positive…

Machine Learning · Computer Science 2022-09-20 Mingzhen He , Fan He , Fanghui Liu , Xiaolin Huang

In this paper we characterize the subspace of $\mathcal{L}_{q,1,v}$ of function which are the q-Bessel Fourier transform of positive functions in $\mathcal{L}_{q,1,v}$. As application we give a q-version of the Bochner's theorem.

Classical Analysis and ODEs · Mathematics 2026-05-12 Lazhar Dhaouadi

We characterize a holomorphic positive definite function $f$ defined on a horizontal strip of the complex plane as the Fourier-Laplace transform of a unique exponentially finite measure on $\mathbb{R}$. The classical theorems of Bochner on…

Complex Variables · Mathematics 2018-01-30 Jorge Buescu , António Paixão

A correspondence between arbitrary Fourier series and certain analytic functions on the unit disk of the complex plane is established. The expression of the Fourier coefficients is derived from the structure of complex analysis. The…

Complex Variables · Mathematics 2015-03-25 Jorge L. deLyra

Fourier transformations of several functions of one and two variables are evaluated and then used to derive some integral and series identities. It is shown that certain double Mordell integrals can be reduced to a sum of products of…

Classical Analysis and ODEs · Mathematics 2020-01-15 Martin Nicholson