Almost every Boolean function has central threshold degree
Abstract
The polynomial threshold degree (or threshold degree) of a Boolean function is the least degree of a real polynomial whose sign represents it. We prove that almost every Boolean function has polynomial threshold degree among the central one or two integers. More precisely, a uniformly chosen Boolean function on n variables has threshold degree either ⌊ n/2⌋ or ⌈ n/2⌉, except with probability at most exp(−c2n/2/n), for an absolute constant c>0 and all sufficiently large n. The paper proves a 1991 conjecture of Aspnes, Beigel, Furst and Rudich. It also proves a 1991 conjecture of Wang and Williams for even n and its main concentration assertion for odd n. A parity example gives a lower bound on the exceptional probability whose exponent differs from ours by a factor of order n. The proof relates polynomial sign representation to recovery of Reed--Muller codes from random erasures, and combines sharp-threshold estimates with bounds on generalized Hamming weights and minimum distance.
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BibTeX
@misc{anthony2026almost,
title = {{Almost every Boolean function has central threshold degree}},
author = {Martin Anthony},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.15057},
eprint = {2610.15057},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.15057},
}
RIS
TY - UNPB
TI - Almost every Boolean function has central threshold degree
AU - Martin Anthony
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.15057
UR - https://arxiv.org/abs/2610.15057
AB - The polynomial threshold degree (or threshold degree) of a Boolean function is the least degree of a real polynomial whose sign represents it. We prove that almost every Boolean function has polynomial threshold degree among the central one or two integers. More precisely, a uniformly chosen Boolean function on n variables has threshold degree either ⌊ n/2⌋ or ⌈ n/2⌉, except with probability at most exp(−c2^n/2/n), for an absolute constant c>0 and all sufficiently large n. The paper proves a 1991 conjecture of Aspnes, Beigel, Furst and Rudich. It also proves a 1991 conjecture of Wang and Williams for even n and its main concentration assertion for odd n. A parity example gives a lower bound on the exceptional probability whose exponent differs from ours by a factor of order n. The proof relates polynomial sign representation to recovery of Reed--Muller codes from random erasures, and combines sharp-threshold estimates with bounds on generalized Hamming weights and minimum distance.
ER -