Abstract
We use elementary algebraic methods to reprove a theorem which was proved by Pop using rigid analytic geometry and in a less general form by Harbater using formal algebraic patching: Let C be an algebraically closed field of cardinality m. Consider a subset S of ℙ1 (C) of cardinality m. Then the fundamental group of ℙ1 (C) \ S is isomorphic to the free profinite group of rank m. We also observe that if char(C) ≠ 0 and 0 < card(S) < m, then π1(ℙ1 (C) \ S) is not isomorphic to a free profinite group.
Original language | English |
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Pages (from-to) | 445-459 |
Number of pages | 15 |
Journal | Pacific Journal of Mathematics |
Volume | 196 |
Issue number | 2 |
DOIs | |
State | Published - Dec 2000 |