Polynomial Lower Bounds for Arithmetic Circuits over Non-Commutative Rings

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autor principal: Raz, Ran
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908990078713856
author Raz, Ran
author_facet Raz, Ran
contents We prove a lower bound of $Ω\left(n^{1.5}\right)$ for the number of product gates in non-commutative arithmetic circuits for an explicit $n$-variate degree-$n$ polynomial $f_{n}$ (over every field). We observe that this implies that over certain non-commutative rings $R$, any arithmetic circuit that computes the induced polynomial function $f_{n}: R^n \rightarrow R$, using the ring operations of addition and multiplication in $R$, requires at least $Ω\left(n^{1.5}\right)$ multiplications. More generally, for any $d\geq 2$ and sufficiently large $n$, we obtain a lower bound of $Ω\left(d\sqrt{n}\right)$ for $n$-variate degree-$d$ polynomials, for both these models. Prior to our work, the only known lower bounds for the size of non-commutative circuits, or for the size of arithmetic circuits over any ring, were slightly super-linear in $\max\{n,d\}$: $Ω\left(n\log d\right)$ by Baur and Strassen, and $Ω\left(d\log n\right)$ by Nisan. (Nisan's bound was proved for non-commutative arithmetic circuits and implies a bound for arithmetic circuits over non-commutative rings by our observation).
format Preprint
id arxiv_https___arxiv_org_abs_2604_22006
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Polynomial Lower Bounds for Arithmetic Circuits over Non-Commutative Rings
Raz, Ran
Computational Complexity
We prove a lower bound of $Ω\left(n^{1.5}\right)$ for the number of product gates in non-commutative arithmetic circuits for an explicit $n$-variate degree-$n$ polynomial $f_{n}$ (over every field). We observe that this implies that over certain non-commutative rings $R$, any arithmetic circuit that computes the induced polynomial function $f_{n}: R^n \rightarrow R$, using the ring operations of addition and multiplication in $R$, requires at least $Ω\left(n^{1.5}\right)$ multiplications. More generally, for any $d\geq 2$ and sufficiently large $n$, we obtain a lower bound of $Ω\left(d\sqrt{n}\right)$ for $n$-variate degree-$d$ polynomials, for both these models. Prior to our work, the only known lower bounds for the size of non-commutative circuits, or for the size of arithmetic circuits over any ring, were slightly super-linear in $\max\{n,d\}$: $Ω\left(n\log d\right)$ by Baur and Strassen, and $Ω\left(d\log n\right)$ by Nisan. (Nisan's bound was proved for non-commutative arithmetic circuits and implies a bound for arithmetic circuits over non-commutative rings by our observation).
title Polynomial Lower Bounds for Arithmetic Circuits over Non-Commutative Rings
topic Computational Complexity
url https://arxiv.org/abs/2604.22006