The analytic space of an analytic manifold #
An analytic manifold M over K = ℝ or ℂ, modelled on a finite-dimensional normed space E with
coordinates ψ : E ≃L[K] Kⁿ, is an analytic K-space in the sense of Hironaka Hir64, Ch. 0, §1,
pp. 119–120: its structure sheaf is the sheaf of analytic functions, with the constants as
K-structure, and (i) every point has a chart domain U on which Sp(M) | U is K-isomorphic to
a local analytic K-space, namely the open G = ψ(φ.target) ⊆ Kⁿ with no equations
(chartLocalModelIso); (ii) M is countable at infinity, being second countable and locally
compact (the model space is finite-dimensional, hence proper, which is where the coordinates ψ
enter); (iii) M is Hausdorff. This module defines
toSpace ψ M : AnalyticSpace K, the analytic spaceSp(M)of a bundled manifoldM : AnalyticManifold K E; its underlyingK-local-ringed space isofManifold K E Mwhatever the coordinatesψ, which enter only the proofs of clauses (i) and (ii);toSpaceHom ψ f : Sp(M) ⟶ Sp(N), the morphism of analytic spaces of an analytic mapf : M → N(ofManifoldHom);J.toAnalyticSpace, the closed analytic subspaceSp(A)/Jof the space of an analytic manifoldAmodelled onKⁿ, cut out by an ideal sheafJ(closedSubspaceonSp(A), the coordinates onKⁿthe identity), with its canonical morphismJ.toAnalyticSpaceι : Sp(A)/J ⟶ Sp(A).
Sp is a functor from analytic manifolds to analytic K-spaces. It is fully faithful
(toSpace_fullyFaithful); its behaviour on open submanifolds, closed
submanifolds, disjoint unions and the dimension strata of a non-singular space is proved in the
neighbouring modules. Through Sp the manifold-level results of the analytic strand (blow-ups of
manifolds, ideal sheaves on manifolds, their strict transforms) are read as statements about
analytic spaces; in particular the ambient blow-up factorization of the resolution theorem for
analytic spaces (Hom.AmbientBlowUpFactorization) writes the closed subspaces of a manifold
through toSpace, and so do the charts of a simple normal crossings divisor set
(IsSncDivisorSet).
Hironaka's clause (i) for the space of a manifold [Hir64, Ch. 0, §1, p. 120]: every point has a
chart domain U such that Sp(M) | U is K-isomorphic to a local analytic K-space, namely the
open ψ(φ.target) of Kⁿ with no equations, restricted to its open subspace ⊤.
The analytic K-space Sp(M) of an analytic manifold M [Hir64, Ch. 0, §1, pp. 119–120]:
the K-local-ringed space (M, 𝒪_M) of analytic functions with Hironaka's clauses (i)–(iii) (see
the module docstring). The coordinates ψ enter only the proofs of clauses (i) and (ii).
Equations
- AnalyticSpace.toSpace ψ M = { toKLocallyRingedSpace := AnalyticSpace.KLocallyRingedSpace.ofManifold K E M.carrier, locallyModel := ⋯, t2 := ⋯, sigmaCompact := ⋯ }
Instances For
The morphism Sp(f) : Sp(M) ⟶ Sp(N) of an analytic map f : M → N between analytic
manifolds: precomposition with f on sections (ofManifoldHom).
Equations
Instances For
Closed subspaces of manifolds as analytic spaces #
The closed analytic subspace Sp(A)/J of the space Sp(A) of an analytic manifold A
modelled on Kⁿ, cut out by the ideal sheaf J, as an analytic K-space: closedSubspace on
Sp(A) (the coordinates on Kⁿ the identity, as in IsSncDivisorSet).
Equations
- J.toAnalyticSpace = (AnalyticSpace.toSpace (ContinuousLinearEquiv.refl K (Fin n → K)) A).closedSubspace J
Instances For
The canonical morphism Sp(A)/J ⟶ Sp(A) of the closed subspace.
Equations
- J.toAnalyticSpaceι = (AnalyticSpace.toSpace (ContinuousLinearEquiv.refl K (Fin n → K)) A).closedSubspaceι J