A plethora of cluster structures on GLn /
M. Gekhtman, M. Shapiro, A. Vainshtein.
- v, 104 pages : illustrations ; 26 cm
- Memoirs of the American Mathematical Society, v. 1486 0065-9266 ; .
- Memoirs of the American Mathematical Society ; v. 1486. .
Includes bibliographical references (pages 103-104).
We continue the study of multiple cluster structures in the rings of regular functions on GLn, SLn and Matn that are compatible with Poisson-Lie and Poisson-homogeneous structures. According to our initial conjecture, each class in the Belavin-Drinfeld classification of Poisson--Lie structures on a semisimple complex group G corresponds to a cluster structure in O(G). Here we prove this conjecture for a large subset of Belavin-Drinfeld (BD) data of An type, which includes all the previously known examples. Namely, we subdivide all possible An type BD data into oriented and non-oriented kinds. In the oriented case, we single out BD data satisfying a certain combinatorial condition that we call aperiodicity and prove that for any BD data of this kind there exists a regular cluster structure compatible with the corresponding Poisson-Lie bracket. In fact, we extend the aperiodicity condition to pairs of oriented BD data and prove a more general result that establishes an existence of a regular cluster structure on SLn compatible with a Poisson bracket homogeneous with respect to the right and left action of two copies of SLn equipped with two different Poisson-Lie brackets. If the aperiodicity condition is not satisfied, a compatible cluster structure has to be replaced with a generalized cluster structure. We will address this situation in future publications.