The complex manifold of a regular fan #
The analytic realization TauCeti.Toric.Fan.analyticRealization of a regular fan is glued from
the affine analytic charts of its cones along the face localizations. This file installs its
complex atlas and proves that it is a complex manifold, modelled on ℂ ^ n for n the rank of
the lattice.
The complex structure on the affine chart of a regular cone comes from an extending integral
basis, which identifies the chart with the open subset ℂ ^ k × (ℂˣ) ^ l of ℂ ^ k × ℂ ^ l,
where k is the number of rays and k + l = n. Choosing such a basis for every cone and
identifying ℂ ^ k × ℂ ^ l linearly with ℂ ^ n makes every affine chart a manifold modelled on
ℂ ^ n. A map into an affine chart is holomorphic for this structure exactly when its values on
all monomials are, which lets every statement be transferred to the structure of any other
extending basis.
Two affine charts are glued along the chart of the intersection cone, through the open face
localizations into both. A face localization is a biholomorphism onto its open image, so the
charts are glued along holomorphic maps, and TopCat.GlueData.chartedSpace gives the
realization a complex atlas making it a complex manifold. For this atlas, the inclusion of every
affine chart, with the complex structure of any extending basis, is a biholomorphism onto its
open image.
Main declarations #
TauCeti.Toric.Fan.analyticChartedSpace: the complex atlas of the analytic realization.TauCeti.Toric.Fan.isManifold_analyticRealization: the analytic realization is a complex manifold.TauCeti.Toric.Fan.analyticAffineChartPartialDiffeomorph: the inclusion of an affine analytic chart is a biholomorphism onto its open image.TauCeti.Toric.Fan.contMDiff_analyticAffineChartι: the inclusion of an affine analytic chart is holomorphic.
References #
- W. Fulton, Introduction to Toric Varieties, §§1.4 and 2.1.
- D. Cox, J. Little and H. Schenck, Toric Varieties, §§3.1 and 3.4.
The same structures, indexed by the index type of the gluing data. Instance search does not
identify this index type with Φ.cones, so the gluing theorems need these forms.
The complex manifold #
The complex atlas of the analytic realization of a regular fan, modelled on ℂ ^ n for n the
rank of the lattice. Its charts are regular affine charts of the cones, transported along the chart
inclusions.
Instances For
The analytic realization of a regular fan is a complex manifold.
The inclusion of the affine analytic chart of a cone into the analytic realization, as a biholomorphism onto its open image. The chart carries the complex structure of any extending basis of the cone.
Instances For
The chart-inclusion biholomorphism is defined on the whole affine analytic chart.
The target of the chart-inclusion biholomorphism is the image of the affine analytic chart.
The chart-inclusion biholomorphism is the inclusion of the affine analytic chart.
The inverse chart-inclusion biholomorphism recovers each affine chart point from its image.
The inclusion of the affine analytic chart of a cone into the analytic realization is holomorphic, for the complex structure of any extending basis of the cone.