activity
20152021
collaborators

7 papers

math.FA2021

Matrix valued positive definite kernels related to the generalized Aitken's integral for Gaussians

V. A. Menegatto, C. P. Oliveira

We introduce a method to construct general multivariate positive definite kernels on a nonempty set that employs a prescribed bounded completely monotone function and special m…

math.CA2018

Relations between Schoenberg Coefficients on Real and Complex Spheres of Different Dimensions

Pier Giovanni Bissiri, Valdir A. Menegatto, Emilio Porcu

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…

math.FA2018

Kolmogorov widths on the sphere via eigenvalue estimates for Hölderian integral operators

Jordão, T., Menegatto +1

Approximation processes in the reproducing kernel Hilbert space associated to a continuous kernel on the unit sphere in the Euclidean space are known to de…

math.CA2018

Strictly Positive Definite Functions on Compact Two-Point Homogeneous Spaces: the Product Alternative

Rafaela N. Bonfim, Jean C. Guella, Valdir A. Menegatto

For two continuous and isotropic positive definite kernels on the same compact two-point homogeneous space, we determine necessary and sufficient conditions in order that their pro…

math.FA2016

Strict positive definiteness on a product of compact two-point homogeneous spaces

V. S. Barbosa, V. A. Menegatto

We present an explicit characterization for the real, continuous, isotropic and strictly positive definite kernels on a product of compact two-point homogeneous spaces, in the case…

math.CA2015

Strictly positive definite kernels on a product of spheres

Jean C. Guella, Valdir A. Menegatto

For the real, continuous, isotropic and positive definite kernels on a product of spheres, one may consider not only its usual strict positive definiteness but also strict positive…