Displaying 61 – 80 of 170

Showing per page

On ramifications divisors of functions in a punctured compact Riemann surface.

Pascual Cutillas Ripoll (1989)

Publicacions Matemàtiques

Let ν be a compact Riemann surface and ν' be the complement in ν of a nonvoid finite subset. Let M(ν') be the field of meromorphic functions in ν'. In this paper we study the ramification divisors of the functions in M(ν') which have exponential singularities of finite degree at the points of ν-ν', and one proves, for instance, that if a function in M(ν') belongs to the subfield generated by the functions of this type, and has a finite ramification divisor, it also has a finite divisor. It is also...

On the five-point theorems due to Lappan

Yan Xu (2011)

Annales Polonici Mathematici

By using an extension of the spherical derivative introduced by Lappan, we obtain some results on normal functions and normal families, which extend Lappan's five-point theorems and Marty's criterion, and improve some previous results due to Li and Xie, and the author. Also, another proof of Lappan's theorem is given.

Currently displaying 61 – 80 of 170