Paper of Juan Miguel Nieto Garcia and Leander Wyss published in Nuclear Physics B

The paper “Jordan blocks and the Bethe ansatz I: The eclectic spin chain as a limit“, co-authored by Juan Miguel Nieto Garcia and Leander Wyss, has been published in the August issue of Nuclear Physics B. It is 46 pages long and published gold open access (with arXiv version here). The paper presents a procedure to extract the generalised eigenvectors of a non-diagonalisable matrix by considering a diagonalisable perturbation of it and computing the non-diagonalisable limit of its eigenvectors. As an example of this process, they compute a subset of the spectrum of the eclectic spin chain by means of the Nested Coordinate Bethe Ansatz. This result show that the Bethe Ansatz of the finitely twisted spin chain contains enough information to reconstruct the generalised eigenvectors of the eclectic spin chain. A screenshot of the journal page is shown below.