Matrix multiplication algorithm: Difference between revisions

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moved alphatensor from lead; seems too early to say whether this result is significant enough for this
new preprint improving matrix mult exponent
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Because [[matrix multiplication]] is such a central operation in many [[numerical algorithm]]s, much work has been invested in making '''matrix multiplication algorithms''' efficient. Applications of matrix multiplication in computational problems are found in many fields including [[scientific computing]] and [[pattern recognition]] and in seemingly unrelated problems such as counting the paths through a [[Graph (graph theory)|graph]].<ref name="skiena"/> Many different algorithms have been designed for multiplying matrices on different types of hardware, including [[parallel computing|parallel]] and [[distributed computing|distributed]] systems, where the computational work is spread over multiple processors (perhaps over a network).
 
Directly applying the mathematical definition of matrix multiplication gives an algorithm that [[Analysis of algorithms|takes time]] on the order of {{math|''n''<sup>3</sup>}} [[Field (mathematics)|field]] operations to multiply two {{math|''n'' × ''n''}} matrices over that field ({{math|Θ(''n''<sup>3</sup>)}} in [[big O notation]]). Better asymptotic bounds on the time required to multiply matrices have been known since the [[Strassen algorithm|Strassen's algorithm]] in the 1960s, but the optimal time (that is, the [[computational complexity of matrix multiplication]]) remains unknown. {{As of|20202022|1210}}, the matrixbest multiplicationannounced algorithmbound withon bestthe [[Time complexity|asymptotic complexity]] runsof ina matrix multiplication algorithm is {{math|O(''n''<sup>2.372859637188</sup>)}} time, given by JoshDuan, AlmanWu and [[Virginia Vassilevska Williams]].Zhou<ref name="aw20dwz22">{{cite conference | last1=Alman | first1=Josh | last2=Williams | first2=Virginia Vassilevska |title=A Refined Laser Method and Faster Matrix Multiplication | year = 2020 | arxiv=2010.05846 |book-title = 32nd Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2021) |url=https://www.siam.org/conferences/cm/program/accepted-papers/soda21-accepted-papers |doi=10.1137/1.9781611976465.32 }}</ref><ref>{{Cite web|last=Hartnett|first=Kevin|title=Matrix Multiplication Inches Closer to Mythic Goal|url=https://www.quantamagazine.org/mathematicians-inch-closer-to-matrix-multiplication-goal-20210323/|access-date=2021-04-01|website=Quanta Magazine|date=23 March 2021|language=en}}</ref> However, this algorithm is a [[galactic algorithm]] because of the large constants and cannot be realized practically.
{{Citation
| last1=Duan
| first1=Ran
| last2=Wu
| first2=Hongxun
| last3=Zhou
| first3=Renfei
| year = 2022
| arxiv=2210.10173
| title = Faster Matrix Multiplication via Asymmetric Hashing
| url=https://arxiv.org/abs/2210.10173}}</ref> announced in a preprint. This improves on the bound of {{math|O(''n''<sup>2.3728596</sup>)}} time, given by Josh Alman and [[Virginia Vassilevska Williams]].<ref name="aw20">
{{Citation
| last1=Alman
| first1=Josh
| last2=Williams
| first2=Virginia Vassilevska
| contribution=A Refined Laser Method and Faster Matrix Multiplication
| year = 2020
| arxiv=2010.05846
| title = 32nd Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2021)
|url=https://www.siam.org/conferences/cm/program/accepted-papers/soda21-accepted-papers
}}</ref><ref>{{Cite web|last=Hartnett|first=Kevin|title=Matrix Multiplication Inches Closer to Mythic Goal|url=https://www.quantamagazine.org/mathematicians-inch-closer-to-matrix-multiplication-goal-20210323/|access-date=2021-04-01|website=Quanta Magazine|date=23 March 2021 |language=en}}</ref> However, this algorithm is a [[galactic algorithm]] because of the large constants and cannot be realized practically.
 
==Iterative algorithm==