English
Related papers

Related papers: Positive-definiteness and integral representations…

200 papers

The integral of a function $f$ defined on a symmetric space $M \simeq G/K$ may be expressed in the form of a determinant (or Pfaffian), when $f$ is $K$-invariant and, in a certain sense, a tensor power of a positive function of a single…

Differential Geometry · Mathematics 2023-06-21 Salem Said , Cyrus Mostajeran

We study the operator-valued positive definite functions on a group using positive block matrices. We give an alternative proof to Brehmer positivity for doubly commuting contractions. We classify all commuting unitary representations over…

Functional Analysis · Mathematics 2024-02-12 Swapan Jana , Sourav Pal , Nitin Tomar

The matrix convexity and the matrix monotony of a real $C^1$ function $f$ on $(0,\infty)$ are characterized in terms of the conditional negative or positive definiteness of the Loewner matrices associated with $f$, $tf(t)$, and $t^2f(t)$.…

Functional Analysis · Mathematics 2010-08-06 Fumio Hiai , Takashi Sano

Positive definite functions on spheres have received an increasing interest in many branches of mathematics and statistics. In particular, the Schoenberg sequences in the spectral representation of positive definite functions have been…

Classical Analysis and ODEs · Mathematics 2019-01-24 Pier Giovanni Bissiri , Valdir A. Menegatto , Emilio Porcu

The strong dual space of linear continuous functionals on a weighted space G of infinitely differentiable functions defined on the real line is described in terms of their Fourier-Laplace transforms.

Functional Analysis · Mathematics 2015-06-26 I. Kh. Musin

The purpose of this paper is to investigate the distribution of zeros of entire functions which can be represented as the Fourier transforms of certain admissible kernels. The principal results bring to light the intimate connection between…

Complex Variables · Mathematics 2014-02-24 George Csordas

The values of the Riemann zeta function at odd positive integers, $\zeta(2n+1)$, are shown to admit a representation proportional to the finite-part of the divergent integral $\int_0^{\infty} t^{-2n-1} \operatorname{csch}t\,\mathrm{d}t$.…

Number Theory · Mathematics 2022-03-23 Eric A. Galapon

We consider the $\alpha$-sine transform of the form $T_\alpha f(y)=\int_0^\infty\vert\sin(xy)\vert^\alpha f(x)dx$ for $\alpha>-1$, where $f$ is an integrable function on $\mathbb{R}_+$. First, the inversion of this transform for $\alpha>1$…

Functional Analysis · Mathematics 2021-07-13 Ly Viet Hoang , Evgeny Spodarev

In this manuscript, the authors derive closed formula for definite integrals of combinations of powers and logarithmic functions of complicated arguments and express these integrals in terms of the Hurwitz zeta. These derivations are then…

General Mathematics · Mathematics 2021-04-30 Robert Reynolds , Allan Stauffer

We define positive and strictly positive definite functions on a domain and study these functions on a list of regular domains. The list includes the unit ball, conic surface, hyperbolic surface, solid hyperboloid, and simplex. Each of…

Classical Analysis and ODEs · Mathematics 2024-01-02 Martin Buhmann , Yuan Xu

In this paper we introduce a new infinite set of transcendental integrals. Each of them is expressed by corresponding value of the function $|\zf|^{-2}$. Such a property is another argument about universality of the Riemann zeta-function…

Classical Analysis and ODEs · Mathematics 2013-09-27 Jan Moser

Mathematical functions, which often appear in mathematical analysis, are referred to as special functions and have been studied over hundreds of years. Many books and dictionaries are available that describe their properties and serve as a…

Classical Analysis and ODEs · Mathematics 2023-11-28 Yoshitaka Okuyama

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

We give the definition of an invariant random positive definite function on a discrete group, generalizing both the notion of an invariant random subgroup and a character. We use von Neumann algebras to show that all invariant random…

Group Theory · Mathematics 2018-04-30 Vadim Alekseev , Rahel Brugger

We study the family of Fourier-Laplace transforms $$ F_{\alpha,\beta}(z)= \operatorname*{F.p.} \int_{0}^{\infty} t^{\beta}\exp(\mathrm{i} t^{\alpha}-\mathrm{i} z t)\:\mathrm{d} t, \quad \operatorname*{Im} z<0, $$ for $\alpha>1$ and…

Complex Variables · Mathematics 2020-10-16 Frederik Broucke , Gregory Debruyne , Jasson Vindas

Suppose $A$ is a positive real linear transformation on a finite dimensional complex inner product space $V$. The reproducing kernel for the Fock space of square integrable holomorphic functions on $V$ relative to the Gaussian measure…

Functional Analysis · Mathematics 2007-05-23 R. Fabec , G. Olafsson , A. Sengupta

We define and study symmetrized and antisymmetrized multivariate exponential functions. They are defined as determinants and antideterminants of matrices whose entries are exponential functions of one variable. These functions are…

Classical Analysis and ODEs · Mathematics 2009-11-13 A. Klimyk , J. Patera

We introduce a symbolic method for the evaluation of definite integrals containing combinations of various functions, including exponentials, logarithm and products of Bessel functions of different types. The method we develop is naturally…

Classical Analysis and ODEs · Mathematics 2011-11-04 D. Babusci , G. Dattoli

We introduce an algorithm to compute the functions belonging to a suitable set ${\mathscr F}$ defined as follows: $f\in {\mathscr F}$ means that $f(s,x)$, $s\in A\subset {\mathbb R}$ being fixed and $x>0$, has a power series expansion…

Number Theory · Mathematics 2023-02-06 Alessandro Languasco

In this article the integration of the $\alpha$-fractal interpolation function $f^{\alpha}$ corresponding to any continuous function $f$ on a compact interval $I$ of $\mathbb{R}$ is estimated although there is no explicit form of…

General Mathematics · Mathematics 2021-12-22 Md Nazimul Islam , Imrul Kaish