Publication Date
Fall 8-2026
Conference/Sponsorship/Institution
Forty-Second Annual Conference on Uncertainty in Artificial Intelligence
Description
TensorSketch by Pham and Pagh [2013], Kar and Karnick [2012] provides efficient sketching algorithms for highdimensional polynomial kernels $\vec{x}^{\otimes p} \in \R^{d^p}$. Kar and Karnick [2012] uses dense Johnson-Lindenstrauss (JL)-type projections with computational cost $O(pDd)$, whereas Pham and Pagh [2013] extends the sparse CountSketch [Charikar et al., 2024] algorithm, yielding a faster algorithm for high-dimensional sparse inputs with running time $O\left(p(\nnz{\vec{x}} + D \log D)\right)$. However, the variance of both estimators grows exponentially with the polynomial degree $p$, scaling as $3^{p}/D$, where $D$ denotes the sketch dimension. Recent work by Wacker et al. [2023] showed that using complex-valued distribution reduces this dependence to $2^{p}/D$ for the approach of Kar and Karnick [2012]. However, their method relies on dense JL-type projections with computational cost $O(pDd)$ and does not extend to the algorithm of Pham and Pagh [2013].
In this work, we introduce a simple variant of TensorSketch [Pham and Pagh, 2013] that achieves the same variance bound as Wacker et al. [2023], while retaining its advantage of the input-sparsity running time. We validate our results with supporting experiments on synthetic and real-world datasets.
Type
Conference Paper
Department
Mathematics
Link to published version
https://openreview.net/forum?id=R7viIEnerG
Recommended Citation
Sharma, Amit; Khan, Mohammad Azhar; Pratap, Rameshwar; and Kang, Keegan, "Improving TensorSketch Using Complex Random Variables" (2026). Faculty Conference Papers and Presentations. 100.
https://digitalcommons.bucknell.edu/fac_conf/100
