A note on letters of Yangian invariants

Abstract Motivated by reformulating Yangian invariants in planar N $$ \mathcal{N} $$ = 4 SYM directly as d log forms on momentum-twistor space, we propose a purely algebraic problem of determining the arguments of the d log’s, which we call “letters”, for any Yangian invariant. These are functions o...

Full description

Bibliographic Details
Main Authors: Song He, Zhenjie Li
Format: Article
Language:English
Published: SpringerOpen 2021-02-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP02(2021)155
_version_ 1819297950569857024
author Song He
Zhenjie Li
author_facet Song He
Zhenjie Li
author_sort Song He
collection DOAJ
description Abstract Motivated by reformulating Yangian invariants in planar N $$ \mathcal{N} $$ = 4 SYM directly as d log forms on momentum-twistor space, we propose a purely algebraic problem of determining the arguments of the d log’s, which we call “letters”, for any Yangian invariant. These are functions of momentum twistors Z ’s, given by the positive coordinates α’s of parametrizations of the matrix C(α), evaluated on the support of polynomial equations C(α) · Z = 0. We provide evidence that the letters of Yangian invariants are related to the cluster algebra of Grassmannian G(4, n), which is relevant for the symbol alphabet of n-point scattering amplitudes. For n = 6, 7, the collection of letters for all Yangian invariants contains the cluster A $$ \mathcal{A} $$ coordinates of G(4, n). We determine algebraic letters of Yangian invariant associated with any “four-mass” box, which for n = 8 reproduce the 18 multiplicative-independent, algebraic symbol letters discovered recently for two-loop amplitudes.
first_indexed 2024-12-24T05:22:09Z
format Article
id doaj.art-2058b6504cf24ab6ad5cb141326a5b48
institution Directory Open Access Journal
issn 1029-8479
language English
last_indexed 2024-12-24T05:22:09Z
publishDate 2021-02-01
publisher SpringerOpen
record_format Article
series Journal of High Energy Physics
spelling doaj.art-2058b6504cf24ab6ad5cb141326a5b482022-12-21T17:13:27ZengSpringerOpenJournal of High Energy Physics1029-84792021-02-012021211510.1007/JHEP02(2021)155A note on letters of Yangian invariantsSong He0Zhenjie Li1CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of SciencesCAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of SciencesAbstract Motivated by reformulating Yangian invariants in planar N $$ \mathcal{N} $$ = 4 SYM directly as d log forms on momentum-twistor space, we propose a purely algebraic problem of determining the arguments of the d log’s, which we call “letters”, for any Yangian invariant. These are functions of momentum twistors Z ’s, given by the positive coordinates α’s of parametrizations of the matrix C(α), evaluated on the support of polynomial equations C(α) · Z = 0. We provide evidence that the letters of Yangian invariants are related to the cluster algebra of Grassmannian G(4, n), which is relevant for the symbol alphabet of n-point scattering amplitudes. For n = 6, 7, the collection of letters for all Yangian invariants contains the cluster A $$ \mathcal{A} $$ coordinates of G(4, n). We determine algebraic letters of Yangian invariant associated with any “four-mass” box, which for n = 8 reproduce the 18 multiplicative-independent, algebraic symbol letters discovered recently for two-loop amplitudes.https://doi.org/10.1007/JHEP02(2021)155Scattering AmplitudesSupersymmetric Gauge Theory
spellingShingle Song He
Zhenjie Li
A note on letters of Yangian invariants
Journal of High Energy Physics
Scattering Amplitudes
Supersymmetric Gauge Theory
title A note on letters of Yangian invariants
title_full A note on letters of Yangian invariants
title_fullStr A note on letters of Yangian invariants
title_full_unstemmed A note on letters of Yangian invariants
title_short A note on letters of Yangian invariants
title_sort note on letters of yangian invariants
topic Scattering Amplitudes
Supersymmetric Gauge Theory
url https://doi.org/10.1007/JHEP02(2021)155
work_keys_str_mv AT songhe anoteonlettersofyangianinvariants
AT zhenjieli anoteonlettersofyangianinvariants
AT songhe noteonlettersofyangianinvariants
AT zhenjieli noteonlettersofyangianinvariants