dorsal/arxiv
View SchemaQuantum graphs of homomorphisms
| Authors | Andre Kornell, Bert Lindenhovius |
|---|---|
| Categories | |
| ArXiv ID | 2601.09685vv2 |
| URL | https://arxiv.org/abs/2601.09685 |
| License | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
Abstract
We introduce a category $\mathsf{qGph}$ of quantum graphs, whose definition is motivated entirely from noncommutative geometry. For all quantum graphs $G$ and $H$ in $\mathsf{qGph}$, we then construct a quantum graph $[G,H]$ of homomorphisms from $G$ to $H$, making $\mathsf{qGph}$ a closed symmetric monoidal category. We prove that for all finite graphs $G$ and $H$, the quantum graph $[G,H]$ is nonempty iff the $(G,H)$-homomorphism game has a winning quantum strategy, directly generalizing the classical case. The finite quantum graphs in $\mathsf{qGph}$ are tracial, real, and self-adjoint, and the morphisms between them are CP morphisms that are adjoint to a unital $*$-homomorphism. We show that Weaver's two notions of a CP morphism coincide in this context. We also show that every finite reflexive quantum graph is the confusability quantum graph of a quantum channel, answering a question of Daws.
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"abstract": "We introduce a category $\\mathsf{qGph}$ of quantum graphs, whose definition is motivated entirely from noncommutative geometry. For all quantum graphs $G$ and $H$ in $\\mathsf{qGph}$, we then construct a quantum graph $[G,H]$ of homomorphisms from $G$ to $H$, making $\\mathsf{qGph}$ a closed symmetric monoidal category. We prove that for all finite graphs $G$ and $H$, the quantum graph $[G,H]$ is nonempty iff the $(G,H)$-homomorphism game has a winning quantum strategy, directly generalizing the classical case.\n The finite quantum graphs in $\\mathsf{qGph}$ are tracial, real, and self-adjoint, and the morphisms between them are CP morphisms that are adjoint to a unital $*$-homomorphism. We show that Weaver\u0027s two notions of a CP morphism coincide in this context. We also show that every finite reflexive quantum graph is the confusability quantum graph of a quantum channel, answering a question of Daws.",
"arxiv_id": "2601.09685",
"authors": [
"Andre Kornell",
"Bert Lindenhovius"
],
"categories": [
"quant-ph",
"math-ph",
"math.CT",
"math.MP",
"math.OA"
],
"license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
"title": "Quantum graphs of homomorphisms",
"url": "https://arxiv.org/abs/2601.09685",
"version": "v2"
},
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