2017/02/22 by Manna, Ramesh
#42B25 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics
paper · doi:10.48550/arxiv.1702.06754
We study the boundedness problem for maximal operators \mathbbM associated to averages along families of finite type curves in the plane, defined by \mathbbMf(x) := sup1 ≤ t ≤ 2 |∫ℂ f(x-ty) ρ(y) dσ(y)|, where dσ denotes the normalised Lebesgue measure over the curves ℂ. Let \triangle be the closed triangle with vertices P=((2)/(5), (1)/(5)), ~ Q=((1)/(2), (1)/(2)), ~ R=(0, 0). In this paper, we prove that for ((1)/(p), (1)/(q)) ∈ (\triangle ∖ \P, Q\) ∩ \((1)/(p), (1)/(q)) :q > m \, there is a constant B such that ‖\mathbbMf‖Lq(ℝ2) ≤ B ‖f‖Lp(ℝ2). Furthermore, if m <5, then we have ‖\mathbbMf‖L5, ∞(ℝ2) ≤ B ‖f‖L(5)/(2) ,1 (ℝ2). We shall also consider a variable coefficient version of maximal theorem and we obtain the Lp-Lq boundedness result for ((1)/(p), (1)/(q)) ∈ \triangle∘ ∩ \((1)/(p), (1)/(q)) :q > m \, where \triangle∘ is the interior of the triangle with vertices (0,0), ~((1)/(2), (1)/(2)), ~((2)/(5), (1)/(5)). An application is given to obtain Lp-Lq estimates for solution to higher order, strictly hyperbolic pseudo-differential operators.