7 papers · 1 filter
Heun operator of Lie type and the modified algebraic Bethe ansatz
Pierre-Antoine Bernard, Nicolas Crampe, Dounia Shaaban Kabakibo +1
The generic Heun operator of Lie type is identified as a certain -Gaudin magnet Hamiltonian in a magnetic field. By using the modified algebraic Bethe ansatz introduced to diag…
Entanglement of Free Fermions on Hadamard Graphs
Nicolas Crampe, Krystal Guo, Luc Vinet
Free Fermions on vertices of distance-regular graphs are considered. Bipartition are defined by taking as one part all vertices at a given distance from a reference vertex. The gro…
The Heun-Racah and Heun-Bannai-Ito algebras
Geoffroy Bergeron, Nicolas Crampé, Satoshi Tsujimoto +2
This paper introduces and studies the Heun-Racah and Heun-Bannai-Ito algebras abstractly and establishes the relation between these new algebraic structures and generalized Heun-ty…
sigma models described through hypergeometric orthogonal polynomials
N. Crampe, A. M. Grundland
The main objective of this paper is to establish a new connection between the Hermitian rank-1 projector solutions of the Euclidean sigma model in two dimensions…
Truncation of the reflection algebra and the Hahn algebra
Nicolas Crampe, Eric Ragoucy, Luc Vinet +1
In the context of connections between algebras coming from quantum integrable systems and algebras associated to the orthogonal polynomials of the Askey scheme, we prove that the t…
Higher rank classical analogs of the Askey-Wilson algebra from the Onsager algebra
Pascal Baseilhac, Nicolas Crampe, Rodrigo A. Pimenta
The -Onsager algebra has been introduced by Uglov and Ivanov in 1995. In this letter, a FRT presentation of the -Onsager algebra is given, its current algebra and commu…