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Motivated by practical applications, I present a novel and comprehensive framework for operator-valued positive definite kernels. This framework is applied to both operator theory and stochastic processes. The first application focuses on…

Statistics Theory · Mathematics 2025-11-04 Saeed Hashemi Sababe

We prove that the solution of certain linear stochastic differential equations in Hilbert spaces, namely those with bounded operators as well as the conservative stochastic Schr\"odinger equations, can be obtained - along the lines of the…

Probability · Mathematics 2010-08-17 Günter Hinrichs

A proof that minimum uncertainty states of the simplest periodic quantum system exist in a state space that is represented by a Colombeau algebra of generalised functions but not in Hilbert space or in the space of Schwartz distributions is…

Mathematical Physics · Physics 2014-06-16 Ian G Fuss , Alexei Filinkov

We connect through the Fourier transform shift-invariant Sobolev type spaces $V_s\subset H^s$, $s\in\mathbb R,$ and the spaces of periodic distributions and analyze the properties of elements in such spaces with respect to the product. If…

Functional Analysis · Mathematics 2024-03-18 Aleksandar Aksentijević , Suzana Aleksić , Stevan Pilipović

In this work, we investigate Gaussian Processes indexed by multidimensional distributions. While directly constructing radial positive definite kernels based on the Wasserstein distance has been proven to be possible in the unidimensional…

We show that various functionals related to the supremum of a real function defined on an arbitrary set or a measure space are Hadamard directionally differentiable. We specifically consider the supremum norm, the supremum, the infimum, and…

Statistics Theory · Mathematics 2019-12-18 Javier Cárcamo , Luis-Alberto Rodríguez , Antonio Cuevas

We investigate an extended version of Hilbert space of analytic functions called Hilbert space of complex-valued harmonic functions. It is found that functions in Hilbert space of complex-valued harmonic functions exhibit many properties…

Complex Variables · Mathematics 2024-10-30 Tseganesh Getachew Gebrehana , Hunduma Legesse Geleta

We tackle the problem of finding a suitable categorical framework for generalized functions used in mathematical physics for linear and non-linear PDEs. We are looking for a Cartesian closed category which contains both Schwartz…

Functional Analysis · Mathematics 2014-02-21 Paolo Giordano , Enxin Wu

In a complete metric space that is equipped with a doubling measure and supports a Poincar\'e inequality, we study strict subsets, i.e. sets whose variational capacity with respect to a larger reference set is finite, in the case $p=1$.…

Metric Geometry · Mathematics 2019-03-12 Panu Lahti

We show that some abstract results on propagation of fixed points for completely positive maps on $C^*$-algebras provide a natural approach to unify recent Noether type theorems on the equivalence of symmetries with conservation laws for…

Operator Algebras · Mathematics 2025-11-04 Aurelian Gheondea

The main goal of this research is to model and investigate generalizations of functions from [31]. Arguments of modeled functions are presented by the representation $\pi_{\mathfrak p}$ from [22].

General Mathematics · Mathematics 2025-05-30 Symon Serbenyuk

This paper studies the probabilistic function approximation problem over reproducing kernel Hilbert spaces. We show the existence and uniqueness of the optimizer under mild assumptions. Furthermore, we generalize the celebrated representer…

Functional Analysis · Mathematics 2025-07-16 Dongwei Chen , Kai-Hsiang Wang

A topological description of various generalized function algebras over corresponding basic locally convex algebras is given. The framework consists of algebras of sequences with appropriate ultra(pseudo)metrics defined by sequences of…

Functional Analysis · Mathematics 2019-04-01 Antoine Delcroix , Maximilian F. Hasler , Stevan Pilipović , Vincent Valmorin

We prove two versions of Bochner's theorem for locally compact quantum groups. First, every completely positive definite "function" on a locally compact quantum group $\G$ arises as a transform of a positive functional on the universal…

Functional Analysis · Mathematics 2021-09-15 Matthew Daws , Pekka Salmi

A new class of bivariate poly-analytic Hermite polynomials is considered. We show that they are realizable as the Fourier-Wigner transform of the univariate complex Hermite functions and form a nontrivial orthogonal basis of the classical…

Complex Variables · Mathematics 2019-08-30 Allal Ghanmi , Khalil Lamsaf

Our main theorem is in the generality of the axioms of Hilbert space, and the theory of unbounded operators. Consider two Hilbert spaces such that their intersection contains a fixed vector space D. It is of interest to make a precise…

Functional Analysis · Mathematics 2017-01-19 Palle Jorgensen , Erin Pearse , Feng Tian

We first construct a space $\mathcal{W}\left( \mathbb{R}_{\text{c}} ^{n}\right) $ whose elements are test functions defined in $\mathbb{R} _{\text{c}}^{n}=\mathbb{R}^{n}\cup\left\{ \mathbf{\infty}\right\} ,$ the one point compactification…

Functional Analysis · Mathematics 2021-08-19 Ricardo Estrada , Jasson Vindas , Yunyun Yang

We give a convergence proof for the approximation by sparse collocation of Hilbert-space-valued functions depending on countably many Gaussian random variables. Such functions appear as solutions of elliptic PDEs with lognormal diffusion…

Numerical Analysis · Mathematics 2017-03-29 Oliver G. Ernst , Björn Sprungk , Lorenzo Tamellini

In this article we study the field of Hilbertian metrics and positive definit (pd) kernels on probability measures, they have a real interest in kernel methods. Firstly we will make a study based on the Alpha-Beta-divergence to have a…

Methodology · Statistics 2018-09-18 Mactar Ndaw , Macoumba Ndour , Papa Ngom

We continue the study of the fractional variation following the distributional approach developed in the previous works arXiv:1809.08575, arXiv:1910.13419 and arXiv:2011.03928. We provide a general analysis of the distributional space…

Functional Analysis · Mathematics 2023-09-07 Giovanni E. Comi , Daniel Spector , Giorgio Stefani