0
riemann tensor=0
where
R=Riemann tensor
0=the surface is flat
A Zariski-Riemann space is a locally ringed space of a subring of a field K, whose points are valuation rings containing k and contained in K, which generalize the Riemann surface of a complex curve.
riemann
Riemann did.
Ziska Riemann's birth name is Franziska Riemann.