In both cases the transcendence degree is the cardinality of the continuum. CH is not needed.
This is a corollary of the following result: let K be any infinite field, and let L/K be any extension. Then
# L = operatorname{max} (# K, operatorname{trdeg}_K L).
To prove this, in turn it suffices to establish the following two results (each of which is straightforward):
1) If K is infinite and L/K is algebraic, then # L = # K.
2) If K is any infinite field, T=tiiinI is an arbitrary set of indeterminates and K(T) is a purely transcendental function field in the indeterminates T, then # K(T) leq # T + # K.
No comments:
Post a Comment