摘要
Let d be a positive integer and八be a collection of partitions of d of the form(a1,...,ap),(b1,...,bq),(m1+1,1,...,1),...,(m1+1,1,...,1),where(m1,...,ml)is a partition of p+g-2>0.We prove that there exists a rational function on the Riemann sphere with branch data ■ if and only if max(m1,...,ml)<d/GCD(a1,...,ap,b1,...bq),As an application,we give a new class of branch data which can be realized by Belyi functions on the Riemann sphere.
基金
supported in part by the National Natural Science Foundation of China(grant no.11426236)
The second author was supported in part by the National Natural Science Foundation of China(grant nos.11571330 and 11971450)
the Fundamental Research Funds for the Central Universities.
