{ "id": "1902.03807", "version": "v1", "published": "2019-02-11T10:33:44.000Z", "updated": "2019-02-11T10:33:44.000Z", "title": "A unified approach to three themes in harmonic analysis ($1^{st}$ part)", "authors": [ "Victor Lie" ], "comment": "104 pages, no figures", "categories": [ "math.AP" ], "abstract": "In the present paper and its sequel \"A unified approach to three themes in harmonic analysis ($2^{nd}$ part)\", we address three rich historical themes in harmonic analysis that rely fundamentally on the concept of non-zero curvature. Namely, we focus on the boundedness properties of (I) the linear Hilbert transform and maximal operator along variable curves, (II) Carleson-type operators in the presence of curvature, and (III) the bilinear Hilbert transform and maximal operator along variable curves. Our Main Theorem states that, given a general variable curve $\\gamma(x,t)$ in the plane that is assumed only to be measurable in $x$ and to satisfy suitable non-zero curvature (in $t$) and non-degeneracy conditions, all of the above itemized operators defined along the curve $\\gamma$ are $L^p$-bounded for $1