Weak nullstellensatz for algebraically closed fields

From Commalg

Statement

Suppose k is an algebraically closed field. Then, the following equivalent statements hold true:

  • Any field K, which is finitely generated as a k-algebra, must be k itself (i.e. isomorphic to k as a k-algebra)
  • For any maximal ideal of the polynomial ring in finitely many variables over k, the quotient field is k
  • The maximal ideals in the polynomial ring k[x1,x2,,xn] are in bijection with the points in kn, where the maximal ideal corresponding to a point (a1,a2,,an) is the ideal (x1a1,x2a2,,xnan)
  • The max-spectrum of k[x1,x2,,xn], with the max-spec topology, is homeomorphic to kn with the Zariski topology, where the bijection is as described above
  • Any proper ideal of k[x1,x2,,xn] has a nonempty vanishing set in kn
  • If a system of polynomial equations over k (in n variables) is consistent (i.e. one cannot derive the equation 0=1 by manipulating them) then the system has a solution in kn