The data of the marked order-reduction functor BMO_{n,m} on analytic manifolds #
Kollár's Theorem 107 ([Kol07, Theorem 107]; the inductive form of [Kol07, Theorem 69]) asserts,
for every m, a smooth blow-up sequence functor BMO_{n,m} on marked triples (X, I, m, E) with
dim X = n such that (1) the final transform has max-ord I_r < m, (2) the functor commutes with
smooth morphisms and with change of fields, and (3) it agrees with BO_{n,m} when
m = max-ord I and E = ∅. This module fixes the class and packages the analytic form of
(1)–(2) as a structure:
AnalyticTriple.BMOClass m— the domain ofBMO_{n,m}:1 ≤ mand only finitely many members of the boundary are nonempty. Kollár'sBMO_{n,m}is defined on all marked triples of dimensionn, with no bound on the order; the class differs fromBOClass mby the missing order clause, and1 ≤ mis imposed because clause (1) cannot hold atm = 0on a nonempty manifold.BMOanData 𝕜 n m— a blow-up sequence functor onBMOClass mat the standard modelContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)with four clauses: (i) its values are smooth blow-up sequences of order≥ mstarting with(M, 𝓘, m, E)([Kol07, Definition 66 (1′)–(4′)]); (ii) Theorem 107 (1), pointwise: the controlled transformΠ^{-1}_*(𝓘, m)at the last stage has order< mat every point; (iii) Theorem 107 (2): the functor commutes with local analytic isomorphisms, the analytic form of [Kol07, 34.1] (the change-of-fields clause has no analytic counterpart); (iv) indifference to empty boundary members. Theorem 107 (3) and Kollár's item 108 are not fields.
The marked data of dimension n - 1 is the input of Lemma 102 ([Kol07, Lemma 102]: the functor
BD_{n,m,j} is BMO_{n-1,m} on the hypersurface E^j, pushed forward and composed with the
first blow-up), in the construction BDan of BD.lean. The functor is valued in finite blow-up
sequences on the whole manifold; the form used by the main theorems is BMOanFam
(Functor/Family.lean), the parameter of the construction of Theorem 103 in OrderReduction/ and
the output of the construction of Theorem 107 (BMO/, Modified/), the recursion on the
dimension closing the loop (Stage/).
The class of the marked order-reduction functors BMO_{n,m} ([Kol07, Theorem 69] and
[Kol07, Theorem 107]: "defined on triples (X, I, m, E) with dim X = n"): 1 ≤ m and only
finitely many members of the boundary are nonempty. There is no order bound: BOClass m is the
subclass with ord 𝓘 ≤ m everywhere.
Instances For
The class's mark is positive.
Only finitely many members of a triple of the class are nonempty.
A triple whose boundary has no member lies in the marked class at mark 1.
(M, 𝓘, ∅) lies in the marked class at mark 1.
The class of BO_{n,m} lies in the class of BMO_{n,m} (Theorem 107 (3),
BMO_{n,m}(X, I, m, E) = BO_{n,m}(X, I, E) when max-ord I = m, presupposes it).
The data of Kollár's marked order-reduction functor BMO_{n,m} ([Kol07, Theorem 107 (1)–(2)])
on analytic manifolds modelled on 𝕜ⁿ: a blow-up sequence functor on the marked class BMOClass m
at the standard model such that its values are smooth blow-up sequences of order ≥ m starting
with (M, 𝓘, m, E) ([Kol07, Definition 66 (1′)–(4′)]), the controlled transform at the last stage
has order < m at every point, the functor commutes with local analytic isomorphisms
([Kol07, 34.1]) and is indifferent to empty boundary members. Theorem 107 (3) and item 108 are
not fields.
The functor is valued in finite blow-up sequences on the whole manifold, which need not be
compact; since the class puts no bound on the order of 𝓘, which may grow without bound towards
infinity, no finite sequence reduces it everywhere, and this structure has no inhabitant in
dimension n ≥ 1 (an observation, not proved in this library). The compatible-family structure
BMOanFam (Functor/Family.lean) is the one
the main theorems use.
- functor : Manifold.AnalyticBlowUpSequenceAssignment (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) fun {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} => Manifold.AnalyticTriple.BMOClass m
The functor
BMO_{n,m}on the marked class at the standard model𝕜ⁿ. - isOfOrderGe {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} (T : Manifold.AnalyticTriple (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) M) (hT : Manifold.AnalyticTriple.BMOClass m T) : (self.functor.seq T hT).toSuccession.IsOfOrderGe T.I m T.F.idealSheaf
The values are smooth blow-up sequences of order
≥ mstarting with(M, 𝓘, m, E)([Kol07, Definition 66 (1′)–(4′)]). - ord_lt {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} (T : Manifold.AnalyticTriple (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) M) (hT : Manifold.AnalyticTriple.BMOClass m T) (x : ((self.functor.seq T hT).toSuccession.stage (Fin.last (self.functor.seq T hT).toSuccession.length)).carrier) : Manifold.IdealSheaf.ord ((self.functor.seq T hT).toSuccession.markedTransformSeq T.I m (Fin.last (self.functor.seq T hT).toSuccession.length)) x < ↑m
Theorem 107 (1),
max-ord I_r < m, pointwise: the controlled transform at the last stage has order< mat every point. - commutesWithLocalIsos : self.functor.CommutesWithLocalIsos
Theorem 107 (2), "commutes with smooth morphisms": the functor commutes with local analytic isomorphisms, both clauses of [Kol07, 34.1].
- indifferentToEmptyMembers : self.functor.IndifferentToEmptyMembers
The functor is indifferent to empty boundary members (
IndifferentToEmptyMembers).