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200 papers

The large variety of Fourier transforms in geometric algebras inspired the straight forward definition of ``A General Geometric Fourier Transform`` in Bujack et al., Proc. of ICCA9, covering most versions in the literature. We showed which…

Algebraic Geometry · Mathematics 2013-06-11 Roxana Bujack , Gerik Scheuermann , Eckhard Hitzer

We give a transform of convergent trigonometric series into equivalent convergent series and sufficient conditions for the transformed series to converge faster than the original one.

Numerical Analysis · Mathematics 2012-08-31 Faton M. Berisha , Milan H. Filipović

In this work we define a Fourier transform for each $f\in L^{p(\cdot)}(\mathbb{R})$, for a large class of exponent functions $p(\cdot)$, as the distributional derivative of a H\"older continuous function. A norm is defined in the space of…

Classical Analysis and ODEs · Mathematics 2025-06-11 André Pedroso Kowacs , Wagner Augusto Almeida de Moraes

In this paper extensions of the classical Fourier, fractional Fourier and Radon transforms to superspace are studied. Previously, a Fourier transform in superspace was already studied, but with a different kernel. In this work, the…

Classical Analysis and ODEs · Mathematics 2008-05-14 Hendrik De Bie

We prove the convergence of layer potential operators for the harmonic transmission problem over a sequence of converging two-sided extension domains. Consequently, the Neumann-Poincar{\'e} operators, Calder{\'o}n projectors, and associated…

Analysis of PDEs · Mathematics 2025-10-24 Gabriel Claret , Anna Rozanova-Pierrat , Alexander Teplyaev

We prove a probabilistic Fourier extension theorem that says Fourier extension holds when averaged over certain smooth Alpert multipliers. The proofs use smooth Alpert wavelets with the classical techniques of stationary phase and…

Classical Analysis and ODEs · Mathematics 2026-04-16 Eric T. Sawyer

The function $y=\Phi_\alpha(x)$, the solution of $y^\alpha e^y=x$ for $x$ and $y$ large enough, has a series expansion in terms of $\ln x$ and $\ln\ln x$, with coefficients given in terms of Stirling cycle numbers. It is shown that this…

Classical Analysis and ODEs · Mathematics 2008-02-03 David J. Jeffrey , Robert M. Corless , David E. G. Hare , Donald E. Knuth

The Riemann-Lebesgue Lemma says that the Fourier transform of an absolutely integrable function on the real line tends to zero as the transform parameter tends to infinity. When the integral is allowed to converge conditionally, the…

Classical Analysis and ODEs · Mathematics 2007-05-23 Erik Talvila

For an eigenfunction of the Laplacian on a hyperbolic Riemann surface, the coefficients of the Fourier expansion are described as intertwining functionals. All intertwiners are classified. A refined growth estimate for the coefficients is…

Differential Geometry · Mathematics 2017-09-04 Anton Deitmar

We provide a rigorous convergence proof demonstrating that the well-known semi-analytical Fourier cosine (COS) formula for the inverse Fourier transform of continuous probability distributions can be extended to discrete probability…

Numerical Analysis · Mathematics 2024-10-10 Xiaoyu Shen , Fang Fang , Chengguang Liu

A fundamental theme in classical Fourier analysis relates smoothness properties of functions to the growth and/or integrability of their Fourier transform. By using a suitable class of $L^{p}-$multipliers, a rather general inequality…

Classical Analysis and ODEs · Mathematics 2013-08-13 William O. Bray

New index transforms are investigated, which contain as the kernel products of the Bessel and modified Bessel functions. Mapping properties and invertibility in Lebesgue spaces are studied for these operators. Relationships with the…

Classical Analysis and ODEs · Mathematics 2015-09-08 Semyon Yakubovich

We propose a new integral based on Taylor measures, study its properties extensively, and we illustrate that it includes many concepts from mathematics as special cases. In particular, the new integral emerges as a generalization of the…

General Mathematics · Mathematics 2026-05-11 Athanasios Christou Micheas

Motivated by applications in number theory, analysis, and fractal geometry, we consider regularity properties and dimensions of graphs associated with Fourier series of the form $F(t)=\sum_{n=1}^\infty f(n)e^{2\pi i nt}/n$, for a large…

Classical Analysis and ODEs · Mathematics 2025-06-13 Efstathios Konstantinos Chrontsios Garitsis , AJ Hildebrand

We introduce a complex q-Fourier transform as a generalization of the (real) one analyzed in [Milan J. Math. {\bf 76} (2008) 307]. By recourse to tempered ultradistributions we show that this complex plane-generalization overcomes all…

Mathematical Physics · Physics 2015-06-03 A. Plastino , M. C. Rocca

The Fourier transform of a bounded measurable function, $f$, on the real line is shown to be the second distributional derivative of a H\"older continuous function. The Fourier transform is written as the difference of $\int_{-1}^1…

Classical Analysis and ODEs · Mathematics 2026-01-26 Erik Talvila

We examine the series expansions of the solutions of the confluent Heun equation in terms of three different sets of the Kummer confluent hypergeometric functions. The coefficients of the expansions in general obey three-term recurrence…

Classical Analysis and ODEs · Mathematics 2014-08-26 T. A. Ishkhanyan , A. M. Ishkhanyan

We prove some non-vanishing results of Hilbert Poincar\'e series. We derive these results, by showing that the Fourier coefficients of Hilbert Poincar\'e series satisfy some nice orthogonality relations for sufficiently large weight as well…

Number Theory · Mathematics 2018-06-26 Moni Kumari

For each $f\in L^p({\mathbb R)}$ ($1\leq p<\infty$) it is shown that the Fourier transform is the distributional derivative of a H\"older continuous function. For each $p$ a norm is defined so that the space Fourier transforms is…

Classical Analysis and ODEs · Mathematics 2025-02-26 Erik Talvila

We compute Fourier transforms of functions expressed as a ratio of one of the Jacobi elliptic functions divided by $\sinh(\pi x)$ or $\cosh(\pi x)$. In many cases, the resulting Fourier transform remains within the same class of functions.…

Classical Analysis and ODEs · Mathematics 2026-03-03 Peng-Cheng Hang , Alexey Kuznetsov