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UCP Maps on Finite Toeplitz Systems
Abstract
We study unital completely positive (UCP) maps on the finite Toeplitz operator system π―d of d Γ d Toeplitz matrices. We give an explicit characterization of pure UCP maps on π―d taking values in Mn in terms of positive nΓ n matrix-valued trigonometric polynomials of degree at most dβ1. This characterization yields a checkable criterion for deciding whether a given UCP map is pure. As an application, we prove that every pure UCP map on π―d has a unique completely positive extension to the generated C*-algebra.
Related
- Finite zero products of Toeplitz operators with harmonic symbols
- Small exponent Schatten class Toeplitz operators on convex domains of finite type
- Non-Bloch band theory for finite banded non-Hermitian Toeplitz matrices
- K-theoretic invariants of the Toeplitz operator system and its dual, and of all graph operator systems
- Constraints on admissible behavior of GMRES applied to tridiagonal Toeplitz systems
BibTeX
@misc{duhan2026maps,
title = {{UCP Maps on Finite Toeplitz Systems}},
author = {Ritul Duhan and Abhay Jindal},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.02561},
eprint = {2606.02561},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.02561},
}
RIS
TY - UNPB
TI - UCP Maps on Finite Toeplitz Systems
AU - Ritul Duhan
AU - Abhay Jindal
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2606.02561
UR - https://arxiv.org/abs/2606.02561
AB - We study unital completely positive (UCP) maps on the finite Toeplitz operator system π―_d of d Γ d Toeplitz matrices. We give an explicit characterization of pure UCP maps on π―_d taking values in M_n in terms of positive nΓ n matrix-valued trigonometric polynomials of degree at most dβ1. This characterization yields a checkable criterion for deciding whether a given UCP map is pure. As an application, we prove that every pure UCP map on π―_d has a unique completely positive extension to the generated C^*-algebra.
ER -