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In the first part of the article, a new interesting system of difference equations is introduced. It is developed for re-rating purposes in general insurance. A nonlinear transformation $\varphi $ of a d-dimensional $(d \ge 2)$ Euclidean…

Optimization and Control · Mathematics 2016-02-12 Muhamed Borogovac

In this paper we consider Wannier functions of quasi-periodic g-gap ($g\geq 1$) potentials and investigate their main properties. In particular, we discuss the problem of averaging underlying the definition of Wannier functions for both…

Mathematical Physics · Physics 2009-11-10 E. D. Belokolos , V. Z. Enolskii , M. Salerno

We prove an intermediate value theorem of an arithmetical flavor, involving the consecutive averages of sequences with terms in a given finite set A. For every such set we completely characterize the numbers x ("intermediate values") with…

General Mathematics · Mathematics 2007-05-23 Mihai Caragiu , Laurence D. Robinson

We find asymptotic equalities for exact upper bounds of approximations by Fourier sums in uniform metric on classes of $2\pi$-periodic functions, representable in the form of convolutions of functions $\varphi$, which belong to unit balls…

Classical Analysis and ODEs · Mathematics 2016-03-08 A. S. Serdyuk , T. A. Stepaniuk

We present a Fourier neural network (FNN) that can be mapped directly to the Fourier decomposition. The choice of activation and loss function yields results that replicate a Fourier series expansion closely while preserving a…

Machine Learning · Computer Science 2021-04-30 Marieme Ngom , Oana Marin

We define a nonlinear Fourier transform which maps sequences of contractive $n \times n$ matrices to $SU(2n)$-valued functions on the circle $\mathbb{T}$. We characterize the image of finitely supported sequences and square-summable…

Classical Analysis and ODEs · Mathematics 2026-03-24 Michel Alexis , Lars Becker , Diogo Oliveira e Silva , Christoph Thiele

In an effort to extend classical Fourier theory, Hedenmalm and Montes-Rodr\'{\i}guez (2011) found that the function system \[ e_m(x)=e^{i\pi mx},\quad e_n^\dagger(x)=e_n(-1/x)=e^{-i\pi n/x} \] is weak-star complete in…

Analysis of PDEs · Mathematics 2026-04-22 H. Hedenmalm , A. Montes-Rodriguez

In the present paper, we deal with Fourier-transformation of Frobenius-Euler polynomials. We shall give its applications by using infinite series. Our applications possess interesting properties which we state in this paper.

Number Theory · Mathematics 2013-08-14 Serkan Araci , Deyao Gao , Mehmet Acikgoz

We propose an alternative approach that avoids the nonlinear equations for the Fourier coefficients that appear in the method of harmonic balance. We apply it to two simple illustrative examples.

Mathematical Physics · Physics 2009-10-12 Francisco M. Fernández

We present a unified framework to study threshold functions for the existence of solutions to linear systems of equations in random sets which includes arithmetic progressions, sum-free sets, $B_{h}[g]$-sets and Hilbert cubes. In…

Combinatorics · Mathematics 2019-02-05 Juanjo Rué , Christoph Spiegel , Ana Zumalacárregui

We present a new method for proving Correa-Jofr\'e-Thibault theorem that monotonicity of subdifferential implies convexity of the function. This new method is based on barrier functions. Barrier functions help overcome some of the main…

Functional Analysis · Mathematics 2024-08-05 Milen Ivanov , Nadia Zlateva

In this paper, we first establish an evaluation formula to calculate Wiener integrals of functionals on Wiener space. We then apply our evaluation formula to carry out very easily calculating for the analytic Fourier-Feynman transform of…

Functional Analysis · Mathematics 2020-01-01 Hyun Soo Chung

This is a sequel to math.AG/0003009. Here we study identities for the Fourier transform of "elementary functions" over finite field containing "exponents" of monomial rational functions. It turns out that these identities are governed by…

Algebraic Geometry · Mathematics 2007-05-23 David Kazhdan , Alexander Polishchuk

Let $f\in L_{2\pi}$ be a real-valued even function with its Fourier series $ \frac{a_{0}}{2}+\sum_{n=1}^{\infty}a_{n}\cos nx,$ and let $S_{n}(f,x), n\geq 1,$ be the $n$-th partial sum of the Fourier series. It is well-known that if the…

Classical Analysis and ODEs · Mathematics 2007-05-23 Dan Sheng Yu , Ping Zhou , Song Ping Zhou

We introduce a rigorous arithmetic--spectral construction associating planar geometric objects with additive prime factor statistics. Let $\mathrm{sopfr}(n)$ denote the sum of prime factors of $n$, counted with multiplicity, and define the…

General Mathematics · Mathematics 2026-02-17 Dimitris Vartziotis

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

We elucidate why an interval algorithm that computes the exact bounds on the amplitude and phase of the discrete Fourier transform can run in polynomial time. We address this question from a formal perspective to provide the mathematical…

Numerical Analysis · Mathematics 2022-05-30 Marco de Angelis

The aim of sequential change-point detection is to issue an alarm when it is thought that certain probabilistic properties of the monitored observations have changed. This work is concerned with nonparametric, closed-end testing procedures…

Methodology · Statistics 2020-10-27 Ivan Kojadinovic , Ghislain Verdier

We introduce a concept of a fractional-derivatives series and prove that any linear partial differential equation in two independent variables has a fractional-derivatives series solution with coefficients from a differentially closed field…

Analysis of PDEs · Mathematics 2008-11-11 D. Grigoriev

We introduce the space of grid functions, a space of generalized functions of nonstandard analysis that provides a coherent generalization both of the space of distributions and of the space of Young measures. We will show that in the space…

Functional Analysis · Mathematics 2019-07-15 Emanuele Bottazzi