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If the Gauss Map of a complete minimal surface omits a Neighborhood of the Sphere, then the surface
is a Plane.  This was proven by Osserman (1959).  Xavier (1981) subsequently generalized the result as follows.
If the Gauss Map of a complete Minimal Surface omits  points, then the surface is a Plane.
 points, then the surface is a Plane.
See also Gauss Map, Minimal Surface, Neighborhood
References
do Carmo, M. P.  Mathematical Models from the Collections of Universities and Museums (Ed. G. Fischer).
  Braunschweig, Germany: Vieweg, p. 42, 1986.
 
Osserman, R.  ``Proof of a Conjecture of Nirenberg.''  Comm. Pure Appl. Math. 12, 229-232, 1959.
 
Xavier, F.  ``The Gauss Map of a Complete Nonflat Minimal Surface Cannot Omit 7 Points on the Sphere.''  Ann. Math.
  113, 211-214, 1981.