3 papers
nlin.SI2026
Quadratic Poisson brackets for the Camassa--Holm peakons
J. Avan, L. Frappat, E. Ragoucy
We establish quadratic Poisson brackets for the generalized Camassa--Holm peakon structure introduced in \cite{AFR23}. The calculation is based on the halving of the spectral param…
math-ph2024
-deformed Griffiths polynomials of Racah type
Nicolas Crampe, Luc Frappat, Julien Gaboriaud +1
New bivariate Griffiths polynomials of -Racah type are introduced and characterized. They generalize the polynomials orthogonal on the multinomial distribution introduced by R.…
math-ph2024
Griffiths polynomials of Racah type
Nicolas Crampe, Luc Frappat, Julien Gaboriaud +3
Bivariate Griffiths polynomials of Racah type are constructed from univariate Racah polynomials. The bispectral properties of the former are deduced from simple properties of the l…