We initiate the study of the $\ell^p(\mathbb{Z}^d)$-boundedness of the arithmetic spherical maximal function over sparse sequences. We state a folklore conjecture for lacunary sequences, a key example of Zienkiewicz and prove new bounds for a family of sparse sequences that achieves the endpoint of the Magyar--Stein--Wainger theorem for the full discrete spherical maximal function. Perhaps our most interesting result is the boundedness of a discrete spherical maximal function in $\mathbb{Z}^4$ over an infinite, albeit sparse, set of radii. Our methods include the Kloosterman refinement for the Fourier transform of the spherical measure (introduced by Magyar) and Weil bounds for Kloosterman sums which are utilized by a new further decomposition of spherical measure.
我们考虑由$ A_{r} f (x) = \int_{\mathbb S ^{n-1}} f (x-r y) \; d σ(y)$给出的半径为$ 0< r< \infty $的球面上的函数$ f$在$ \mathbb R ^{n}$上的平均值，其中$ σ$是$ \mathbb S ^{n-1}$上的归一化旋转不变测度。我们证明了两个极大函数，第一个缺球极大函数，第二个完整的极大函数的稀疏边界的尖锐范围。$$ M_{lac} f = \sup_{j\in \mathbb Z } A_{2^j} f , \qquad M_{full} f = \sup_{ r>0 } A_{r} f . $$稀疏边界是这些极大函数的已知$L^p$边界的非常精确的变体。它们来自于已知的$ L ^{p}$，这些极大函数的本地化版本的改进估计，在我们的稀疏界的指数是尖锐的。我们得到新的加权不等式的权重在某些Muckenhoupt和反向Hölder类的交集。
