Let k be a differential
field of characteristic 0, and Ω be a universal extension of k. Suppose that
the field of constants k0 of k is algebraically closed. Consider the following
dlfferential polynomial of the first order over k in a single indeterminate
y:
here
Take a generic point z of the general solution of T. Then, z is transcendental over k,
and k(z,z′) is called a differential elliptic function field.
We prove the following:
Theorem. Let k(z,z′) be a differential elliptic function field over k. Then, there
exists a finitely generated differential extension field k∗ of k such that the following
three conditions are satisfied:
- z is transcendental over k∗;
- the field of constants of k∗ is the same as k0;
- there exists an element ζ of Ω such that k∗(z,z′) = k∗(ζ,ζ′) and (ζ′)2 =
4S(ζ;κ) with the same modulus as κ.
|