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New York Journal of Mathematics
Volume 27 (2021), 631-675

  

Sayan Bagchi, Sourav Hait, Luz Roncal, and Sundaram Thangavelu

On the maximal function associated to the spherical means on the Heisenberg group

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Published: April 25, 2021.
Keywords: Spherical means, Heisenberg group, Lp-improving estimates, sparse domination, weighted theory.
Subject: Primary: 43A80. Secondary: 22E25, 22E30, 42B15, 42B25.

Abstract
In this paper we deal with lacunary and full versions of the spherical maximal function on the Heisenberg group Hn, for n ≥ 2. By suitable adaptation of an approach developed by M. Lacey in the Euclidean case, we obtain sparse bounds for these maximal functions, which lead to new unweighted and weighted estimates. In particular, we deduce the Lp boundedness, for 1 < p < ∞, of the lacunary maximal function associated to the spherical means on the Heisenberg group. In order to prove the sparse bounds, we establish Lp - Lq estimates for local (single scale) variants of the spherical means.

Acknowledgements

The first-named author was partially supported by Inspire Faculty Fellowship [DST/INSPIRE/04/2016/000776]. The first, second, and third authors were supported by 2017 Leonardo grant for Researchers and Cultural Creators, BBVA Foundation. The fourth author was visiting Basque Center for Applied Mathematics through a Visiting Fellow programme. The third and fourth-named author were also supported by the Basque Government through BERC 2018--2021 program, by Spanish Ministry of Science, Innovation and Universities through BCAM Severo Ochoa accreditation SEV-2017-2018 and the project MTM2017-82160-C2-1-P funded by AEI/FEDER, UE. The third author also acknowledges the RyC project RYC2018-025477-I and IKERBASQUE.


Author information

Sayan Bagchi:
Stat-Math Unit
Indian Statistical Institute
Kolkata, India;
Current Address: Department of Mathematics and Statistics
Indian Institute of Science Education and Research Kolkata
Mohanpur 741246, Nadia, West Bengal, India

sayansamrat@gmail.com

Sourav Hait:
Department of Mathematics
Indian Institute of Science
560 012 Bangalore, India

souravhait@iisc.ac.in

Luz Roncal:
BCAM - Basque Center for Applied Mathematics
48009 Bilbao, Spain;
and Ikerbasque, Basque Foundation for Science
48011 Bilbao, Spain

lroncal@bcamath.org

Sundaram Thangavelu:
Department of Mathematics
Indian Institute of Science
560 012 Bangalore, India;
and BCAM - Basque Center for Applied Mathematics
48009 Bilbao, Spain

veluma@iisc.ac.in