,
Abhibhav Garg
Creative Commons Attribution 4.0 International license
We study the question of explicitly constructing variety-evasive subspace families, a pseudorandom primitive introduced by Guo (Computational Complexity 2024) that generalizes both hitting sets and lossless rank condensers. Roughly speaking, a variety-evasive subspace family ℋ is a collection of subspaces such that for every algebraic variety V in a fixed family ℱ, there is some subspace W ∈ ℋ that is in general position with respect to V.
We give an explicit construction of a subspace families that evade all degree-d varieties in an n-dimensional affine or projective space. Our construction improves on the size of the variety-evasive subspace families constructed by Guo and, for varieties of degree n^{1 + Ω(1)}, is polynomially close to Guo’s lower bound on the size of any such variety-evasive subspace family. Our variety-evasive subspace families rely on an improved construction of hitting sets for Chow forms of algebraic varieties.
@InProceedings{andrews_et_al:LIPIcs.APPROX/RANDOM.2026.56,
author = {Andrews, Robert and Garg, Abhibhav},
title = {{An Improved Construction of Variety-Evasive Subspace Families}},
booktitle = {Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques (APPROX/RANDOM 2026)},
pages = {56:1--56:12},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-449-9},
ISSN = {1868-8969},
year = {2026},
volume = {392},
editor = {Singh, Mohit and Gur, Tom},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.APPROX/RANDOM.2026.56},
URN = {urn:nbn:de:0030-drops-277738},
doi = {10.4230/LIPIcs.APPROX/RANDOM.2026.56},
annote = {Keywords: algebraic complexity, pseudorandomness, varieties, variety-evasive subspaces, Chow forms}
}