Factoring Modular Polynomials
โ Scribed by J. VON ZUR GATHEN; S. HARTLIEB
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 642 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0747-7171
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โฆ Synopsis
This paper gives an algorithm to factor a polynomial f (in one variable) over rings like Z /rZ for r โ Z or F q [y]/rF q [y] for r โ F q [y]. The Chinese Remainder Theorem reduces our problem to the case where r is a prime power. Then factorization is not unique, but if r does not divide the discriminant of f , our (probabilistic) algorithm produces a description of all (possibly exponentially many) factorizations into irreducible factors in polynomial time. If r divides the discriminant, we only know how to factor by exhaustive search, in exponential time.
๐ SIMILAR VOLUMES
We describe an efficient new algorithm for factoring a polynomial ฮฆ(x) over a field k that is complete with respect to a discrete prime divisor. For every irreducible factor ฯ(x) of ฮฆ(x) this algorithm returns an integral basis for k[x]/ฯ(x)k[x] over k.
For several decades the standard algorithm for factoring polynomials f with rational coefficients has been the Berlekamp-Zassenhaus algorithm. The complexity of this algorithm depends exponentially on n, where n is the number of modular factors of f . This exponential time complexity is due to a com