Algorithms for solving linear systems over cyclotomic fields

We consider the problem of solving a linear system A x = b over a cyclotomic field. Cyclotomic fields are special in that we can easily find a prime p for which the minimal polynomial m ( z ) for the field factors into a product of distinct linear factors. This makes it possible to develop fast modu...

Celý popis

Uloženo v:
Podrobná bibliografie
Vydáno v:Journal of symbolic computation Ročník 45; číslo 9; s. 902 - 917
Hlavní autoři: Chen, Liang, Monagan, Michael
Médium: Journal Article
Jazyk:angličtina
Vydáno: Elsevier Ltd 01.09.2010
Témata:
ISSN:0747-7171, 1095-855X
On-line přístup:Získat plný text
Tagy: Přidat tag
Žádné tagy, Buďte první, kdo vytvoří štítek k tomuto záznamu!
Popis
Shrnutí:We consider the problem of solving a linear system A x = b over a cyclotomic field. Cyclotomic fields are special in that we can easily find a prime p for which the minimal polynomial m ( z ) for the field factors into a product of distinct linear factors. This makes it possible to develop fast modular algorithms. We give two output sensitive modular algorithms, one using multiple primes and Chinese remaindering, the other using linear p -adic lifting. Both use rational reconstruction to recover the rational coefficients in the solution vector. We also give a third algorithm which computes the solutions as ratios of two determinants modulo m ( z ) using Chinese remaindering only. Because this representation is d = deg m ( z ) times more compact in general, we can compute it the fastest. We have implemented the algorithms in Maple. Our benchmarks show that the third method is fastest on random inputs, but on real inputs arising from problems in computational group theory, the first two methods are faster because the solutions have small rational coefficients.
ISSN:0747-7171
1095-855X
DOI:10.1016/j.jsc.2010.05.001