,
Pushkar S. Joglekar
Creative Commons Attribution 4.0 International license
We consider read-k determinantal representations of polynomials and prove some non-expressibility results. A square matrix M whose entries are variables or field elements will be called read-k, if every variable occurs at most k times in M. It will be called a determinantal representation of a polynomial f if f = det(M). We show that - the n × n permanent polynomial does not have a read-k determinantal representation for k ∈ o(√n/log n) (over a field of characteristic different from two). We also obtain a quantitative strengthening of this result by giving a similar non-expressibility for k ∈ o(√n/log n) for an explicit n-variate multilinear polynomial (as opposed to the permanent which is n²-variate).
@InProceedings{hrubes_et_al:LIPIcs.STACS.2025.53,
author = {Hrube\v{s}, Pavel and Joglekar, Pushkar S.},
title = {{On Read-k Projections of the Determinant}},
booktitle = {42nd International Symposium on Theoretical Aspects of Computer Science (STACS 2025)},
pages = {53:1--53:7},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-365-2},
ISSN = {1868-8969},
year = {2025},
volume = {327},
editor = {Beyersdorff, Olaf and Pilipczuk, Micha{\l} and Pimentel, Elaine and Thắng, Nguy\~{ê}n Kim},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.STACS.2025.53},
URN = {urn:nbn:de:0030-drops-228785},
doi = {10.4230/LIPIcs.STACS.2025.53},
annote = {Keywords: determinant, permanent, projection of determinant, VNP completeness of permanent}
}