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We study both averaging and maximal averaging problems for Product $j$-varieties defined by $Pi_j={xin mathbb F_q^d: prod_{k=1}^d x_k=j}$ for $jin mathbb F_q^*,$ where $mathbb F_q^d$ denotes a $d$-dimensional vector space over the finite field $mathbb F_q$ with $q$ elements. We prove the sharp $L^pto L^r$ boundedness of averaging operators associated to Product $j$-varieties. We also obtain the optimal $L^p$ estimate for a maximal averaging operator related to a family of Product $j$-varieties ${Pi_j}_{jin mathbb F_q^*}.$
We study maximal operators associated to singular averages along finite subsets $Sigma$ of the Grassmannian $mathrm{Gr}(d,n)$ of $d$-dimensional subspaces of $mathbb R^n$. The well studied $d=1$ case corresponds to the the directional maximal functio
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
We study the finite field extension estimates for Hamming varieties $H_j, jin mathbb F_q^*,$ defined by $H_j={xin mathbb F_q^d: prod_{k=1}^d x_k=j},$ where $mathbb F_q^d$ denotes the $d$-dimensional vector space over a finite field $mathbb F_q$ with
We exhibit a range of $ell ^{p}(mathbb{Z}^d)$-improving properties for the discrete spherical maximal average in every dimension $dgeq 5$. The strategy used to show these improving properties is then adapted to establish sparse bounds, which extend t
For a polynomial $P$ mapping the integers into the integers, define an averaging operator $A_{N} f(x):=frac{1}{N}sum_{k=1}^N f(x+P(k))$ acting on functions on the integers. We prove sufficient conditions for the $ell^{p}$-improving inequality begin{e