2026/07/16 by Gianmarco Brocchi, Andreas Rosén
Mathematics · #math.AP #math.CA
On d-dimensional cylinders C= ℝk× N, with a closed manifold N as base and large scale dimension k∈[1,d), we prove quadratic estimates in weighted L2 space for Dirac operators perturbed by bounded, measurable and accretive coefficients. This gives in particular homogeneous Kato square root estimates on C for Riesz transforms associated with second order divergence form elliptic operators, having measurable coefficients with degeneracy governed by a Muckenhoupt A2 weight. By localisation and scaling, it also yields local quadratic estimates for perturbed Dirac operators on general manifolds with locally thin cylindrical geometry, and possibly with zero injectivity radius.