Complexity of Bezout's Theorem V: Polynomial Time

نویسندگان

  • Michael Shub
  • Stephen Smale
چکیده

The main goal of this paper is to show that the problem of finding approximately a zero of a polynomial system of equations can be solved in polynomial time, on the average. The number of arithmetic operations is bounded by cN4, where N is the number of input variables and c is a universal constant. Let us be more precise. For d = (d 1, . . . , d,) each di a positive integer, let ZCd, be the linear space of all maps f: C’+ ’ + C”, f=(fi, . ,fn), where each fi is a homogeneous polynomial of degree di. The notion of an approximate zero z in projective space P(C”+‘) of f has been defined in [ll, 12,14,6] and below. It means that Newton’s method converges quadratically, immediately, to an actual zero [ of ,fi starting from z. Given an approximate zero, an E approximation of an actual zero can be obtained with a further log (log E 1 number of steps.

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عنوان ژورنال:
  • Theor. Comput. Sci.

دوره 133  شماره 

صفحات  -

تاریخ انتشار 1994