English

The local Tb theorem with rough test functions

Classical Analysis and ODEs 2020-07-10 v2

Abstract

We prove a local TbTb theorem under close to minimal (up to certain `buffering') integrability assumptions, conjectured by S. Hofmann (El Escorial, 2008): Every cube is assumed to support two non-degenerate functions bQ1Lpb^1_Q\in L^p and bQ2Lqb^2_Q\in L^q such that 12QTbQ1Lq1_{2Q}Tb^1_Q\in L^{q'} and 12QTbQ2Lp1_{2Q}T^*b^2_Q\in L^{p'}, with appropriate uniformity and scaling of the norms. This is sufficient for the L2L^2-boundedness of the Calderon-Zygmund operator TT, for any p,q(1,)p,q\in(1,\infty), a result previously unknown for simultaneously small values of pp and qq. We obtain this as a corollary of a local TbTb theorem for the maximal truncations T#T_{\#} and (T)#(T^*)_{\#}: for the L2L^2-boundedness of TT, it suffices that 1QT#bQ11_Q T_{\#}b^1_Q and 1Q(T)#bQ21_Q (T^*)_{\#}b^2_Q be uniformly in L0L^0. The proof builds on the technique of suppressed operators from the quantitative Vitushkin conjecture due to Nazarov-Treil-Volberg.

Keywords

Cite

@article{arxiv.1206.0907,
  title  = {The local Tb theorem with rough test functions},
  author = {Tuomas Hytönen and Fedor Nazarov},
  journal= {arXiv preprint arXiv:1206.0907},
  year   = {2020}
}

Comments

V2: 24 pages, incorporates referee comments, accepted for publication in Adv Math

R2 v1 2026-06-21T21:14:26.568Z