No CrossRef data available.
Published online by Cambridge University Press: 01 June 2008
For a numerical semigroup S, a positive integer a and a nonzero element m of S, we define a new numerical semigroup R(S,a,m) and call it the (a,m)-rotation of S. In this paper we study the Frobenius number and the singularity degree of R(S,a,m). Moreover, we observe that the rotations of ℕ are precisely the modular numerical semigroups.
The first author gratefully acknowledges support of the FCT through the CMUP. The second author was supported by the project MTM2004-01446 and FEDER founds.