diff 9506729..b1f9bc4 global_solvably_closed_galois_v2.txt
diff --git a/global_solvably_closed_galois_v2.txt b/global_solvably_closed_galois_v2.txt
index 2004261..da6b006 100644
--- a/global_solvably_closed_galois_v2.txt
+++ b/global_solvably_closed_galois_v2.txt
@@ -10,114 +10,6 @@ A complete, self-contained proof of Uchida's conjecture.
hypothesis is required.
-CONTENTS
---------
- 0. What this paper is about, in plain words
- 1. Conventions, solvably closed fields, and the five black boxes
- 2. Additive characters and Frobenius detection
- 3. Extension to the normalizer, and generation by Frobenius
- 4. Matching residue characteristics
- 5. Identifying the homomorphism, and the main theorem
- 6. References
-
-
-=====================================================================
-0. WHAT THIS PAPER IS ABOUT, IN PLAIN WORDS
-=====================================================================
-
-A number field is a field you get by adjoining finitely many roots
-of polynomials to the rational numbers Q; for example Q(i), where
-i^2 = -1. Attach to a number field F all of its algebraic extensions
-at once. The symmetries of that giant object form the absolute
-Galois group G_F. Its finite quotients are exactly the Galois groups
-of the finite Galois extensions of F.
-
-A famous theme of arithmetic geometry ("anabelian geometry", due to
-Neukirch, Iwasawa, Uchida and others) says: G_F remembers F, and in
-fact remembers maps between fields. Two prototype theorems drive
-this paper:
-
- (a) ISOMORPHISM THEOREM. If two such absolute Galois groups are
- abstractly isomorphic, the number fields are isomorphic. More
- precisely (Uchida 1979), an isomorphism of Galois groups of
- "solvably closed" extensions comes from a field isomorphism.
-
- (b) THE QUESTION OF THIS PAPER. What happens for HOMOMORPHISMS
- that are not isomorphisms but still "open" (their image is an
- open, hence large, subgroup)? Uchida conjectured in 1981 that
- every such open homomorphism is again induced by a field
- embedding. We prove this in full, with no hypothesis on the
- kernel.
-
-"Solvably closed" is a technical convenience. A field extension E/F
-is solvably closed if E has no nontrivial abelian extension. The
-algebraic closure Q-bar is the leading example; the maximal
-prosolvable extension Q^s of Q (the union of all finite solvable
-Galois extensions of Q) is another. Every solvably closed field
-contains Q^s. Because of this, the whole problem reduces to a single
-statement about one object:
-
- P = Gal(Q^s / Q),
-
-the absolute Galois group of the maximal prosolvable extension. The
-central technical theorem (Theorem 5.3 below) says: every continuous
-open homomorphism G_F -> P is conjugate, inside P, to ordinary
-restriction. Everything else is bookkeeping that passes from P down
-to a general pair of solvably closed fields.
-
-WHY IT IS HARD, AND THE STRATEGY.
- Uchida already knew that an open homomorphism phi : G_F -> P
- behaves arithmetically "most of the time": for any fixed auxiliary
- prime l, at almost every prime where a pro-l piece of local
- inertia survives, phi matches source primes to target primes
- (the "partial local correspondence"). The trouble is that WHICH
- primes match, and which are missed, depends on l. Different l
- give different, incompatible-looking partial pictures. The task
- is to extract one clean global statement (equality of cyclotomic
- characters) out of these l-dependent shadows.
-
- Three ideas make this work.
-
- (1) CHARACTER TESTS. Continuous additive Q_l-valued characters
- x of a Galois group are determined by their values at
- Frobenius elements: if x vanishes at infinitely many primes
- of residue degree one, then x is zero. This rests on a
- logarithm-rank lemma (a special case of the l-adic
- Waldschmidt-Masser theorem), which we prove in full. Variants
- for averaged and corestricted characters handle primes of
- any residue degree.
-
- (2) GENERATION. Restricting to an open normal subgroup and
- extending to its normalizer, we enlarge finite quotients of
- P using many copies of a regular module (a Kummer trick from
- Uchida 1979). This produces enough characters to show that
- images of source Frobenius elements generate entire target
- cyclic subgroups. Consequences: the extended map is
- SURJECTIVE, and its cyclotomic logarithms agree with the
- source for every prime l in an infinite congruence class.
-
- (3) MATCHING AND UNIFORMITY. After ascending to Q(i) and a
- quadratic preimage K, one Kummer estimate bounds the number
- of target primes that the partial correspondence can miss
- for a fixed l by a number depending only on K, not on l.
- A simultaneous power-residue construction then picks one l
- that excludes all the "wrong characteristic" partners at
- once, forcing a genuine same-characteristic partner for
- almost every split target prime. Splitting completely in a
- suitable finite extension finally aligns the two character
- pullbacks, and a faithful representation identifies the maps
- modulo every finite quotient. Compactness produces a single
- conjugation.
-
-The proof below makes each of these ideas precise. Part 1 fixes
-notation and lists the five external inputs (Uchida isomorphism,
-centralizer lemma, Uchida local correspondence, Hoshi cyclotomic
-criterion, and the fact that Q^s is solvably closed). The remaining
-parts are self-contained, with the log-rank lemma and every other
-substantive step proved in full.
-
-
-=====================================================================
1. CONVENTIONS, SOLVABLY CLOSED FIELDS, AND THE BLACK BOXES
=====================================================================