Computing greatest common divisors and factorizations in quadratic number fields
نویسندگان
چکیده
منابع مشابه
Computing Greatest Common Divisors and Factorizations in Quadratic Number Fields*
In a quadratic number field Q(√ D ), D a squarefree integer, with class number 1 any algebraic integer can be decomposed uniquely into primes but for only 21 domains Euclidean algorithms are known. It was shown by Cohn [5] that for D ≤ – 19 even remainder sequences with possibly non-decreasing norms cannot determine the GCD of arbitrary inputs. We extend this result by showing that there does...
متن کاملComputing Greatest Common Divisors and Factorizations
In a quadratic number field Q(V~D), D a squarefree integer, with class number 1, any algebraic integer can be decomposed uniquely into primes, but for only 21 domains Euclidean algorithms are known. It was shown by Cohn [5] that for D < —19 even remainder sequences with possibly nondecreasing norms cannot determine the GCD of arbitrary inputs. We extend this result by showing that there does no...
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Definition 2.1. When a and b are integers, we say a divides b if b = ak for some k ∈ Z. We then write a | b (read as “a divides b”). Example 2.2. We have 2 | 6 (because 6 = 2 · 3), 4 | (−12), and 5 | 0. We have ±1 | b for every b ∈ Z. However, 6 does not divide 2 and 0 does not divide 5. Divisibility is a relation, much like inequalities. In particular, the relation 2 | 6 is not the number 3, e...
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Differential (Ore) type polynomials with “approximate” polynomial coefficients are introduced. These provide an effective notion of approximate differential operators, with a strong algebraic structure. We introduce the approximate Greatest Common Right Divisor Problem (GCRD) of differential polynomials, as a non-commutative generalization of the well-studied approximate GCD problem. Given two ...
متن کاملApproximate Greatest Common Divisors and Polynomials Roots
This lecture will show by example some of the problems that occur when the roots of a polynomial are computed using a standard polynomial root solver. In particular, polynomials of high degree with a large number of multiple roots will be considered, and it will be shown that even roundoff error due to floating point arithmetic, in the absence of data errors, is sufficient to cause totally inco...
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ژورنال
عنوان ژورنال: Mathematics of Computation
سال: 1989
ISSN: 0025-5718
DOI: 10.1090/s0025-5718-1989-0982367-2