The Lovász number is not alone: a continuum of Rényi points in the entanglement-assisted spectrum of graphs
In plain wordsThe zero-error capacity of a noisy channel helped by shared entanglement is the minimum of a special family of graph quantities, of which one famous member was known; a whole continuum belongs to it, and a published conjecture about the five-cycle holds.
The result
As the paper states it, in briefMinimizing Petz–Rényi information radii over classical–quantum channels compatible with a graph gives a continuum of points between known graph parameters; a 1440-vertex graph has strictly below the projective rank of its complement.
Questionson the index
- Answered Do the middle links of the Duan–Winter chain of zero-error quantities ever separate, and what are they on the pentagon? posed by others
- Answered Is the Lovász number the only Rényi point in the entanglement-assisted spectrum of graphs?
- Open Is the projective rank of a graph’s complement in its entanglement-assisted spectrum? left open
How this was checked
- Machine checks
- Deterministic checks with pinned output, including an exact re-check of Theorem D. Version 1.1.0 corrected an overstated claim of version 1.0.0. Corrections
- Lean
- None.
- Peer review
- Not yet.
Every check here is internal. How we check results.
Novelty and credit
- Novelty
- New, with named precedent: Vrana’s interpolation already gives a continuum with the same values on the pentagon in the ordinary asymptotic spectrum; the new points lie in the entanglement-assisted spectrum. The three endpoint quantities are Duan and Winter’s, and order zero is due to Schrijver (as credited by Dalai) and to Duan and Winter.
Versionsfive, each with its own DOI
| Version | Date | DOI | Notes |
|---|---|---|---|
| 1.2.1 | 10.5281/zenodo.23375704 | Correction: Credit added to Oufkir, Yao and Berta for the data-processing inequality behind non-signalling simulation, and to Wang and Duan (2018); Shariat, Hoogsteder-Riera and Tomamichel are described as giving an alternative proof. Section 1.1 said “the first three” terms of the Duan–Winter chain are radii, which would have included S_NS; corrected. A verification section that printed a number matching no statement of the paper is removed. PDF hosted here. | |
| 1.2.0 | 10.5281/zenodo.23328355 | ||
| 1.1.1 | 10.5281/zenodo.23328240 | Correction: Credit and precision, after an attribution audit and a referee audit that found no false result: θ0 = θ is credited to Schrijver (as Dalai’s Theorem 8), to Duan and Winter, and to Cabello, Severini and Winter; Wang and Duan’s answer to Duan and Winter’s question, Vrana’s continuum on C5 in the ordinary spectrum, Li and Zuiddam, and others are credited; a figure caption’s witness radius had been rounded in the unsafe direction. No theorem changes. | |
| 1.1.0 | 10.5281/zenodo.23066485 | Correction: Version 1.0.0 stated that both pentagon geometries in Figure 4 are nonoptimal throughout 0 < α < 1/2; the displayed bounds do not show this. Version 1.1.0 states only the proved regimes. The package also corrects a SHA-256 digest in the certificate README. | |
| 1.0.0 | 10.5281/zenodo.22983499 |
Paper, code and links
papers/lovasz-v1.2.1.pdf, version 1.2.1, 805,507 bytes.SHA-256 477dd4d6a4142cc130e345cd496bcfa81035e389201fdfa46f5d5fc74c6aeb82
- DOI
10.5281/zenodo.23375704; all versions 10.5281/zenodo.22983498
- arXiv
Corrections
- Version 1.2.1. Credit added to Oufkir, Yao and Berta for the data-processing inequality behind non-signalling simulation, and to Wang and Duan (2018); Shariat, Hoogsteder-Riera and Tomamichel are described as giving an alternative proof. Section 1.1 said “the first three” terms of the Duan–Winter chain are radii, which would have included SNS; corrected. A verification section that printed a number matching no statement of the paper is removed.doi:10.5281/zenodo.23375704
- Version 1.1.1. Credit and precision, after an attribution audit and a referee audit that found no false result: θ0 = θ is credited to Schrijver (as Dalai’s Theorem 8), to Duan and Winter, and to Cabello, Severini and Winter; Wang and Duan’s answer to Duan and Winter’s question, Vrana’s continuum on C5 in the ordinary spectrum, Li and Zuiddam, and others are credited; a figure caption’s witness radius had been rounded in the unsafe direction. No theorem changes.doi:10.5281/zenodo.23328240
- Version 1.1.0. Version 1.0.0 stated that both pentagon geometries in Figure 4 are nonoptimal throughout 0 < α < 1/2; the displayed bounds do not show this. Version 1.1.0 states only the proved regimes. The package also corrects a SHA-256 digest in the certificate README.doi:10.5281/zenodo.23066485
All corrections, and what counts as one.
Cite
@misc{mghirbi2026lovasz,
author = {Mghirbi, Nidhal and Douglas, Seth},
title = {The {L}ovász number is not alone: a continuum of {R}ényi points in the entanglement-assisted spectrum of graphs},
year = {2026},
version = {1.2.1},
doi = {10.5281/zenodo.23375704},
url = {https://doi.org/10.5281/zenodo.23375704},
eprint = {2610.20775},
archiveprefix = {arXiv}
}