title: Castelnuovo surface
text: # Castelnuovo surface
  
  In mathematics, a Castelnuovo surface is a surface of general type such that the canonical bundle is very ample and such that $c_1^2$ = $3p_g$ − 7. Guido Castelnuovo proved that if the canonical bundle is very ample for a surface of general type then $c_1^2$ ≥ $3p_g$ − 7.
  
  