Period-space plumbing and the pushforward map (jacobian-functoriality §8, pushforward half) #
Unit: jacobian-functoriality. RS.periodCoordEquiv (the dualMap/Basis.dualBasis.equivFun
coordinatization of the ambient period space, spiked in scratch_jfun.lean), pushforwardT
(the induced ℂ-linear map on period spaces from Form1.pullback), and
periodSubgroup_le_comap_pushforwardT (hT for the pushforward direction — exact membership,
no closure/density needed, via pathIntegral_pullback + basepoint-flexible
periodVector_mem_periodSubgroup). Assembles Jacobian.pushforward via Jacobian.inducedHom.
Scope note: only the pushforward direction is built in this unit (see the root file's
LEDGER for the pullback-direction gap: Form1.trace's branch-point analyticity and the
trace–path-integral relation are not completed, so pullbackT/Jacobian.pullback/
pushforward_pullback cannot be assembled here).
The dualMap/Basis.dualBasis.equivFun coordinatization of the ambient period space: a
period vector periodVector (basis X) γ is exactly pathIntegralₗ γ read in (basis X)'s
dual-basis coordinates (§8.1, spiked in scratch_jfun.lean).
Equations
Instances For
The induced ℂ-linear map on period spaces, from Form1.pullback f hf's dualMap
(contravariant: Form1 Y →ₗ Form1 X transposes to Dual(Form1 X) →ₗ Dual(Form1 Y), exactly the
pushforward direction).
Equations
- RS.pushforwardT f hf = ↑(RS.periodCoordEquiv Y) ∘ₗ (RS.Form1.pullback f hf).dualMap ∘ₗ ↑(RS.periodCoordEquiv X).symm
Instances For
The pushforward map on period vectors, computed at a based loop: pushforwardT sends the
period vector of γ to the period vector of its image loop γ.map hf.continuous
(pathIntegral_pullback's naturality, transported through the coordinatization).
hT for the pushforward direction (§8.2 — exact containment, no closure/density needed).
Jacobian.pushforward (§8.4): the pushforward map between Jacobians associated to a
holomorphic map of the underlying curves.