The A3 Narain family over ℤ4
Abstract
The code {000,220,202,022}⊂ℤ43 realizes the split A3 root-weight gluing construction as ordinary Construction A, preserving the Lorentzian pairing and the positive energy form. For two hyperbolic pairs of A3 blocks, the twenty-two even self-dual gluing codes form seven block-monomial classes. Explicit metric and B-field representatives and theta series distinguish exactly seven T-duality classes in this family at central charge six; the one-pair family has two classes at central charge three. For arbitrary d, the chiral root system on either side is A13m, where m counts the words (2ei,2ei) in the gluing code. Exactly one two-pair class has no zero-B T-duality frame. Intersections of gluing codes determine finite shift orbifolds between the backgrounds, with the target code specifying the twisted-sector projections.
Related
BibTeX
@misc{sammani2026narain,
title = {{The $A_3$ Narain family over $\mathbbZ_4$}},
author = {Rajae Sammani and Abdellah Sebbar},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26610},
eprint = {2610.26610},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26610},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The A_3 Narain family over ℤ_4
AU - Rajae Sammani
AU - Abdellah Sebbar
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26610
UR - https://arxiv.org/abs/2610.26610
AB - The code {000,220,202,022}⊂ℤ_4^3 realizes the split A_3 root-weight gluing construction as ordinary Construction A, preserving the Lorentzian pairing and the positive energy form. For two hyperbolic pairs of A_3 blocks, the twenty-two even self-dual gluing codes form seven block-monomial classes. Explicit metric and B-field representatives and theta series distinguish exactly seven T-duality classes in this family at central charge six; the one-pair family has two classes at central charge three. For arbitrary d, the chiral root system on either side is A_1^3m, where m counts the words (2e_i,2e_i) in the gluing code. Exactly one two-pair class has no zero-B T-duality frame. Intersections of gluing codes determine finite shift orbifolds between the backgrounds, with the target code specifying the twisted-sector projections.
ER -