4 papers · 1 filter
Algebraic interpretation of the two-variable Jacobi polynomials on the triangle: the pentagonal way
Nicolas Crampé, Quentin Labriet, Lucia Morey +3
The rank two Jacobi algebra is used to provide an interpretation of the two-variable Jacobi polynomials on the triangle, as overlaps betwee…
symmetry of XX spin chains
Nicolas Crampé, Rafael I. Nepomechie, Luc Vinet +1
We show that, after suitably adjusting a uniform transverse magnetic field, the generic inhomogeneous open XX spin chain has a two-fold degeneracy, and an exact symmetry wh…
Exactly solvable inhomogeneous XY spin chain
Pierre-Antoine Bernard, Nicolas Crampé, Quentin Labriet +2
Analytical expressions for the eigenvalues of certain inhomogeneous XY spin chains are computed. These models are rewritten in terms of free-fermion models using a well-known Jorda…
Contiguity relations for finite families of orthogonal polynomials in the Askey scheme
Nicolas Crampé, Lucia Morey, Luc Vinet +1
This paper classifies the contiguity relations for finite families of polynomials within the (-)Askey scheme. The necessary and sufficient conditions for the existence of these…