Karim Belabas on Fri, 07 Nov 2014 13:30:53 +0100 |
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Re: Cube roots mod prime powers |
* Charles Greathouse [2014-11-07 06:04]: > Is there a way to find cube roots mod prime powers, rather than just > primes? Modular roots are handled by gen_Shanks_sqrtn, which is quite > specific to primes, but I don't know if there's away to do Hensel lifting > other than 'by hand'. ? t = lift(sqrtn(2 + O(31^5), 3, &z)) %1 = 21483438 ? (t + O(31^5))^3 %2 = 2 + O(31^5) > Also, is there a way to get Fp_sqrtn's *zeta from gp? ? z %3 = 25 + 16*31 + 6*31^2 + 22*31^3 + 12*31^4 + O(31^5) Cheers, K.B. -- Karim Belabas, IMB (UMR 5251) Tel: (+33) (0)5 40 00 26 17 Universite de Bordeaux Fax: (+33) (0)5 40 00 69 50 351, cours de la Liberation http://www.math.u-bordeaux1.fr/~kbelabas/ F-33405 Talence (France) http://pari.math.u-bordeaux1.fr/ [PARI/GP] `