{ "id": "1805.06060", "version": "v1", "published": "2018-05-15T22:49:15.000Z", "updated": "2018-05-15T22:49:15.000Z", "title": "Endpoint sparse bounds for Walsh-Fourier multipliers of Marcinkiewicz type", "authors": [ "Amalia Culiuc", "Francesco Di Plinio", "Michael Lacey", "Yumeng Ou" ], "comment": "24 pages, 4 figures. Submitted", "categories": [ "math.CA" ], "abstract": "We prove sharp endpoint-type sparse bounds for Walsh-Fourier Marcinkiewicz multipliers and Littlewood-Paley square functions. These results are motivated by conjectures of Lerner in the Fourier setting. As a corollary, we obtain a sharp range of weighted norm inequalities for these operators. In particular, we obtain the sharp growth rate of the $L^p$ weighted operator norm in terms of the $A_p$ characteristic in the full range $1