On the automorphisms of the power semigroups of a numerical semigroup
arXiv:2604.26901 · doi:10.1112/tlm3.70030
Abstract
If is a numerical semigroup (that is, a cofinite subset of the non-negative integers closed under addition), then the non-empty subsets of form a semigroup under the sumset operation induced by addition in . Moreover, if , then is a monoid with identity element , and the family of all subsets of containing is a submonoid of . We show that the automorphism group of is trivial, and the same holds for when . The proofs blend ideas from combinatorics and semigroup theory.
10 pages. To appear in the Transactions of the London Math. Soc