The complex plane with the origin removed, i.e., . The punctured plane is sometimes denoted (although this notation conflicts with that for the Riemann sphere C-*, or extended complex plane). It is both a Lie group and an Abelian variety.
Punctured Plane
See also
C-*, Complex Plane, Punctured Set, Riemann SphereExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Punctured Plane." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PuncturedPlane.html