General transmission in genus one #
The periodic assembly of the three row formulas in GenusOneRankDelta: an
exact principal residue gives a translated affine simple reflection, while no
principal residue gives a translation. The resulting inversion bounds are
already checked in that module, so this file is composition and case analysis.
The shape of the argument, for a fixed divisor D:
- submodularity supplies a transmission permutation
τ, affine at the torsion witness (exists_affineTransmissionPermutation_of_submodular); - if no degree-zero member of the marked twist orbit is principal,
τis a translation and has no inversion classes at all; - otherwise fix a principal index
c. At an exact torsion order the principal indices are exactlycmodk, soτlowers the row atc, raises the row atc - 1, and is the ordinary translated identity everywhere else. That is preciselyaffineReflection k (c-1)translated by1 - deg D, which has at most one inversion class.
The k = 1 case is separated out because affineReflection needs 2 ≤ k.
There every index is principal, so τ is again a translation.
theorem
Bananas.kGeneralTransmission_genusOne_of_torsionOrder_and_allSubmodular
{M : TwiceMarked}
{k : ℕ}
(hConnected : _root_.graphConnected M.graph)
(hGenus : M.graph.genus = 1)
(hOrder : IsTorsionOrder M k)
(hSub : AllSubmodular M)
:
A connected genus-one twice-marked graph with exact torsion order and all divisors submodular has general transmission at that order.