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We study an extension of the Falconer distance problem in the multiparameter setting. Given $ellgeq 1$ and $mathbb{R}^{d}=mathbb{R}^{d_1}timescdots timesmathbb{R}^{d_ell}$, $d_igeq 2$. For any compact set $Esubset mathbb{R}^{d}$ with Hausdorff dimension larger than $d-frac{min(d_i)}{2}+frac{1}{4}$ if $min(d_i) $ is even, $d-frac{min(d_i)}{2}+frac{1}{4}+frac{1}{4min(d_i)}$ if $min(d_i) $ is odd, we prove that the multiparameter distance set of $E$ has positive $ell$-dimensional Lebesgue measure. A key ingredient in the proof is a new multiparameter radial projection theorem for fractal measures.
The first purpose of this paper is to provide new finite field extension theorems for paraboloids and spheres. By using the unusual good Fourier transform of the zero sphere in some specific dimensions, which has been discovered recently in the work
Given $E subseteq mathbb{F}_q^d times mathbb{F}_q^d$, with the finite field $mathbb{F}_q$ of order $q$ and the integer $d ge 2$, we define the two-parameter distance set as $Delta_{d, d}(E)=left{left(|x_1-y_1|, |x_2-y_2|right) : (x_1,x_2), (y_1,y_2)
We prove a point-wise and average bound for the number of incidences between points and hyper-planes in vector spaces over finite fields. While our estimates are, in general, sharp, we observe an improvement for product sets and sets contained in a s
It is shown that product BMO of Chang and Fefferman, defined on the product of Euclidean spaces can be characterized by the multiparameter commutators of Riesz transforms. This extends a classical one-parameter result of Coifman, Rochberg, and Weiss,
Given a compact $E subset mathbb{R}^n$ and $s > 0$, the maximum distance problem seeks a compact and connected subset of $mathbb{R}^n$ of smallest one dimensional Hausdorff measure whose $s$-neighborhood covers $E$. For $Esubset mathbb{R}^2$, we prov