Let
k be a field containing
Fq. Let
ψ be a rank
r Drinfeld
Fq[t]-module determined by
ψt(X)=tX+a1Xq+⋯+ar−1Xqr−1+Xqr, where
t,a1,…,ar−1 are algebraically independent over
k . Let
n∈Fq[t] be a monic polynomial. We show that the Galois group of
145b119009754e0bf00767718f0" title="Click to view the MathML source">ψn(X) over
k(t,a1,…,ar−1) is isomorphic to
GLr(Fq[t]/nFq[t]), settling a conjecture of Abhyankar. Along the way we obtain an explicit construction of Drinfeld moduli schemes of level
tn.
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