Weighted restriction estimates using polynomial partitioning (1512.03238v2)

Abstract: We use the polynomial partitioning method of Guth to prove weighted Fourier restriction estimates in $\Bbb R^3$ with exponents $p$ that range between $3$ and $3.25$, depending on the weight. As a corollary to our main theorem, we obtain new (non-weighted) local and global restriction estimates for compact $C^\infty$ surfaces $S \subset \Bbb R^3$ with strictly positive second fundamental form. For example, we establish the global restriction estimate $| Ef |{L^p(\Bbb R^3)} \leq C \, | f |{L^q(S)}$ in the full conjectured range of exponents for $p > 3.25$ (up to the sharp line), and the global restriction estimate $| Ef |{L^p(\Omega)} \leq C \, | f |{L^2(S)}$ for $p>3$ and certain sets $\Omega \subset \Bbb R^3$ of infinite Lebesgue measure. As a corollary to our main theorem, we also obtain new results on the decay of spherical means of Fourier transforms of positive compactly supported measures on $\Bbb R^3$ with finite $\alpha$-dimensional energies.