Discrete total variation under the multinomial, Part 5: cyclic total variation

arXiv:2611.14735v1 Announce Type: new Abstract: We study the cyclic discrete total variation obtained by adding the wrap-around edge to the usual open-chain statistic. Under the uniform multinomial law the cyclic symmetry recombines the same per-edge, adjacent, and disjoint covariance blocks used for the linear statistic, but with different multiplicities, and this simplifies the variance: the bin-independent leading coefficient \(2A+4B\) carries over, the constant-order correction collapses \emph{exactly} to \(\beta_c(n)=\beta_1 n\) (no \(n^0\) or \(1/n\) tail; obtained directly here, and already reached in Part~2 through the transfer identity), and a conditional second-order coefficient \(\gamma_c(n)\) is given. The exact finite-\(N\) cyclic--linear transfer identity of Part~2, read order by order, both delivers these and, as its main consequence for the \emph{linear} statistic, explains the traveling mode of the linear variance: comparison with the (first-order) mode-free symmetric cyclic profile shows that deleting one edge introduces a rising contribution whose balance against the falling cyclic bulk creates a ridge at \(n\asymp\sqrt{K_0N}\) with local optimizer \(K_0=C_1/\beta_1\). Uniform control of three ridge blocks proves this optimizer on every compact ridge window, upgrading the previously heuristic \(\sqrt N\) mode law to a theorem; the global localization of the exact maximizer remains open. We also record the corresponding cyclic reference-centered statistic under a fixed alternative and the leading Nabeya variance formula for the matched non-uniform cyclic statistic. Throughout, ``exact'' refers to the asymptotic coefficient in \(N\); the operative symmetry is cyclic stationarity (rotation invariance), not exchangeability.

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