The lifted finite-axis drift is Lipschitz across the axis #
For the lifted drift B_n = (V_n X/R, W_n) of eq:drift:Bn:def and its divergence
2 V_n / R (continued to the axis by 2 ∂_R V_n), at a fixed time τ ≤ -1 and on a ball of
the lifted space mapped into the unit cylinder, both are bounded and Lipschitz with constants
depending only on the constant of eq:aniso:bounds: the footnote to eq:drift:Bn:def,
|B_n| + |∇B_n| ≤ C |τ|^{-1/2}, read as a Lipschitz bound across the axis. The direction
X/R is singular at the axis, but |V_n| ≤ C R there, and
R₂ |X/R₁ - Y/R₂| ≤ |R₁ - R₂| + |X - Y|.
The lifted radius is 2-Lipschitz for the sup norm of Vec 5.
|V_n| ≤ C R on a rectangle through the axis mapped into the cylinder, at τ ≤ -1.
The lifted drift is Lipschitz with constant 7C on a ball of the lifted space mapped into the
cylinder at a time τ ≤ -1.
The lifted divergence is 2 times the continued quotient V_n / R.
The lifted divergence is Lipschitz with constant 12C on a ball mapped into the cylinder.
The pointwise bounds ‖B_n‖ ≤ C and |div B_n| ≤ 2C on the lifted preimage at τ ≤ -1.