Editing Ramification (mathematics) (section)

==In complex analysis==
{{see also|Branch point}}
[[File:Riemann surface sqrt.svg|thumb|Using the [[Riemann surface]] of the square root]]
In [[complex analysis]], the basic model can be taken as the ''z''&nbsp;&rarr;&nbsp;''z''<sup>''n''</sup> mapping in the complex plane, near&nbsp;''z''&nbsp;=&nbsp;0. This is the standard local picture in [[Riemann surface]] theory, of ramification of order&nbsp;''n''. It occurs for example in the [[Riemann–Hurwitz formula]] for the effect of mappings on the [[genus (mathematics)|genus]].