Petz-Rényi Relative Entropy of Thermal States and their Displacements

Fuente: arXiv
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Main Authors: Androulakis, George, John, Tiju Cherian
Format: Preprint
Published: 2023
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author Androulakis, George
John, Tiju Cherian
author_facet Androulakis, George
John, Tiju Cherian
contents In this article, we obtain the precise range of the values of the parameter $α$ such that Petz-Rényi $α$-relative entropy $D_α(ρ||σ)$ of two displaced thermal states is finite. More precisely, we prove that, given two displaced thermal states $ρ$ and $σ$ with inverse temperature parameters $r_1, r_2,\dots, r_n$ and $s_1,s_2, \dots, s_n$, respectively, we have \[ D_α(ρ||σ)<\infty \Leftrightarrow α< \min \left\{ \frac{s_j}{s_j-r_j}: j \in \{ 1, \ldots , n \} \text{ such that } r_j<s_j \right\}, \] where we adopt the convention that the minimum of an empty set is equal to infinity. Along the way, we prove a special case of a conjecture of Seshdreesan, Lami and Wilde (J. Math. Phys. 59, 072204 (2018)).
format Preprint
id arxiv_https___arxiv_org_abs_2303_03380
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Petz-Rényi Relative Entropy of Thermal States and their Displacements
Androulakis, George
John, Tiju Cherian
Quantum Physics
Mathematical Physics
Primary 81P17, Secondary 81P99
In this article, we obtain the precise range of the values of the parameter $α$ such that Petz-Rényi $α$-relative entropy $D_α(ρ||σ)$ of two displaced thermal states is finite. More precisely, we prove that, given two displaced thermal states $ρ$ and $σ$ with inverse temperature parameters $r_1, r_2,\dots, r_n$ and $s_1,s_2, \dots, s_n$, respectively, we have \[ D_α(ρ||σ)<\infty \Leftrightarrow α< \min \left\{ \frac{s_j}{s_j-r_j}: j \in \{ 1, \ldots , n \} \text{ such that } r_j<s_j \right\}, \] where we adopt the convention that the minimum of an empty set is equal to infinity. Along the way, we prove a special case of a conjecture of Seshdreesan, Lami and Wilde (J. Math. Phys. 59, 072204 (2018)).
title Petz-Rényi Relative Entropy of Thermal States and their Displacements
topic Quantum Physics
Mathematical Physics
Primary 81P17, Secondary 81P99
url https://arxiv.org/abs/2303.03380