Extensions of Operator-Valued Kernels on $\mathbb{F}^{+}_{d}$

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autor principal: Tian, James
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866911206699171840
author Tian, James
author_facet Tian, James
contents We study the problem of extending a positive-definite operator-valued kernel, defined on words of a fixed finite length from a free semigroup, to a global kernel defined on all words. We show that if the initial kernel satisfies a natural one-step dominance inequality on its interior, a global extension that preserves this interior data and the dominance property is always possible. This extension is constructed explicitly via a Cuntz-Toeplitz model. For the problem of matching the kernel on the boundary, we introduce an intrinsic shift-consistency condition. We prove this condition is sufficient to guarantee the existence of a global extension that agrees with the original kernel on its entire domain.
format Preprint
id arxiv_https___arxiv_org_abs_2510_10935
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Extensions of Operator-Valued Kernels on $\mathbb{F}^{+}_{d}$
Tian, James
Functional Analysis
Primary: 47A20, secondary: 44A60, 46E22, 47A57, 47B32
We study the problem of extending a positive-definite operator-valued kernel, defined on words of a fixed finite length from a free semigroup, to a global kernel defined on all words. We show that if the initial kernel satisfies a natural one-step dominance inequality on its interior, a global extension that preserves this interior data and the dominance property is always possible. This extension is constructed explicitly via a Cuntz-Toeplitz model. For the problem of matching the kernel on the boundary, we introduce an intrinsic shift-consistency condition. We prove this condition is sufficient to guarantee the existence of a global extension that agrees with the original kernel on its entire domain.
title Extensions of Operator-Valued Kernels on $\mathbb{F}^{+}_{d}$
topic Functional Analysis
Primary: 47A20, secondary: 44A60, 46E22, 47A57, 47B32
url https://arxiv.org/abs/2510.10935