{ "id": "2505.06220", "version": "v1", "published": "2025-05-09T17:55:55.000Z", "updated": "2025-05-09T17:55:55.000Z", "title": "Hamiltonian formalism for non-diagonalisable systems of hydrodynamic type", "authors": [ "Paolo Lorenzoni", "Sara Perletti", "Karoline van Gemst" ], "comment": "43 pages", "categories": [ "math-ph", "math.MP" ], "abstract": "We study the system of first order PDEs for pseudo-Riemannian metrics governing the Hamiltonian formalism for systems of hydrodynamic type. In the diagonal setting the integrability conditions ensure the compatibility of this system and, thanks to a classical theorem of Darboux, the existence of a family of solutions depending on functional parameters. In this paper we study the generalisation of this result to a class of non-diagonalisable systems of hydrodynamic type that naturally generalises Tsarev's integrable diagonal systems.", "revisions": [ { "version": "v1", "updated": "2025-05-09T17:55:55.000Z" } ], "analyses": { "keywords": [ "hydrodynamic type", "hamiltonian formalism", "non-diagonalisable systems", "generalises tsarevs integrable diagonal systems", "integrability conditions ensure" ], "note": { "typesetting": "TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable" } } }