Discrete Lagrangian Multiforms for ABS Equations II: Tetrahedron and Octahedron Equations

• Published in: Symmetry, Integrability and Geometry: Methods and Applications
• Date: 2025
• ISSN: 1815-0659
• Main Authors: Richardson, Jacob J., Vermeeren, Mats
• Format: Article
• Language: English
• Published: Інститут математики НАН України 2025
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/213517
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Discrete Lagrangian Multiforms for ABS Equations II: Tetrahedron and Octahedron Equations. Jacob J. Richardson and Mats Vermeeren. SIGMA 21 (2025), 059, 27 pages

We present four types of discrete Lagrangian 2-form associated with the integrable quad equations of the ABS list. These include the triangle Lagrangian that has traditionally been used in the Lagrangian multiform description of ABS equations, the trident Lagrangian that was central to Part I of thi...