Density of numerical sets associated to a numerical semigroup

Autor: Deepesh Singhal, Yuxin Lin
Rok vydání: 2021
Předmět:
Zdroj: Communications in Algebra. 49:4291-4303
ISSN: 1532-4125
0092-7872
DOI: 10.1080/00927872.2021.1918136
Popis: A numerical set is a co-finite subset of the natural numbers that contains zero. Its Frobenius number is the largest number in its complement. Each numerical set has an associated semigroup $A(T)=\{t\mid t+T\subseteq T\}$, which has the same Frobenius number as $T$. For a fixed Frobenius number $f$ there are $2^{f-1}$ numerical sets. It is known that there is a number $\gamma$ close to $0.484$ such that the ratio of these numerical sets that are mapped to $N_f=\{0\}\cup(f,\infty)$ is asymptotically $\gamma$. We identify a collection of families $N(D,f)$ of numerical semigroups such that for a fixed $D$ the ratio of the $2^{f-1}$ numerical sets that are mapped to $N(D,f)$ converges to a positive limit as $f$ goes to infinity. We denote the limit as $\gamma_D$, these constants sum up to $1$ meaning that they asymptotically account for almost all numerical sets.
Comment: 13 pages
Databáze: OpenAIRE