Sharp convex body sparse bounds and quantitative matrix weighted estimates for Hilbert transforms along curves

arXiv:2610.40820v1 Announce Type: new Abstract: We prove convex body sparse bounds for coordinatewise Hilbert transforms along monomial curves and local $C^d$ curves with uniformly nonvanishing torsion on the closed integration interval. Adapting the scalar estimates of Cladek--Ou \cite{CladekOu2018} and the lifting method of Laukkarinen--Lorist \cite{LaukkarinenLorist2026} to the anisotropic geometry, we obtain one sparse family of genuine curve-adapted boxes and quantitative $L^p(W)$ bounds for matrix weights. The convex body sparse exponent range is sharp up to its boundary: estimates hold in the interior of $\Omega_d$, while any fixed finite number of sparse families fails outside $\overline{\Omega_d}$ when $1/r+1/s>1$. We also establish an explicit endpoint-contact obstruction. For every interior planar exponent pair, a polynomial curve with positive torsion on the open integration interval violates the full-interval sparse estimate.

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