OAI/NumberTheory/DukePrimeDegree/Dynamics/VelocityMembershipMeasurable.lean
4 declarations, 0 contain sorry, 0 declared as axioms
Measurable tests for actual component velocities
For a fixed matrix, membership in the velocity space of a component stabilizer is a measurable event. The exponential characterization makes it a countable collection of ordinary stabilizer tests. Rational times suffice because the subgroup and its matrix image are closed.
- lemma
OAI.DukePrimeDegree.all_exp_mem_iff_rational_exp_memline 22 - lemma
OAI.DukePrimeDegree.mem_matrixVelocitySpace_iff_rational_expline 42 - lemma
OAI.DukePrimeDegree.measurableSet_kernel_exp_invariantline 50 - theorem
OAI.DukePrimeDegree.measurableSet_kernel_velocity_memline 80Source documentation
This tests the genuine differentiable-curve velocity space. No measurable choice of subgroup curves is assumed or made.
theorem measurableSet_kernel_velocity_mem {Z : Type*} [MeasurableSpace Z] {n : ℕ} [Nonempty (Fin n)] (κ : Kernel Z (X n)) [IsFiniteKernel κ] (V : Matrix (Fin n) (Fin n) ℝ) : MeasurableSet {z | V ∈ matrixVelocitySpace (invariantRightSubgroup (κ z))} := by …Mentions: OAI.DukePrimeDegree.matrixVelocitySpace