English

Central invariants revisited

Differential Geometry 2018-10-23 v2 Mathematical Physics math.MP Exactly Solvable and Integrable Systems

Abstract

We use refined spectral sequence arguments to calculate known and previously unknown bi-Hamiltonian cohomology groups, which govern the deformation theory of semi-simple bi-Hamiltonian pencils of hydrodynamic type with one independent and N N dependent variables. In particular, we rederive the result of Dubrovin-Liu-Zhang that these deformations are parametrized by the so-called central invariants, which are N N smooth functions of one variable.

Keywords

Cite

@article{arxiv.1611.09134,
  title  = {Central invariants revisited},
  author = {Guido Carlet and Reinier Kramer and Sergey Shadrin},
  journal= {arXiv preprint arXiv:1611.09134},
  year   = {2018}
}

Comments

Accepted for publication in Journal de l'\'Ecole polytechnique - Math\'ematiques

R2 v1 2026-06-22T17:06:24.030Z