Arithmetic Complexity in Ring Extensions
نویسندگان
چکیده
Given a polynomial f with coefficients from a field F, is it easier to compute f over an extension ring R than over F? We address this question, and show the following. For every polynomial f , there is a noncommutative extension ring R such that F is in the center of R and f has a polynomial-size formula over R. On the other hand, if F is algebraically closed, no commutative extension ring R can reduce formula or circuit complexity of f . To complete the picture, we prove that over any field, there exist hard polynomials with zero-one coefficients. (This is a basic theorem, but we could not find it written explicitly.) Finally, we show that low-dimensional extensions are not very helpful in computing polynomials. As a corollary, we obtain that the elementary symmetric polynomials have formulas of size nO(log logn) over any field, and that division gates can be efficiently eliminated from circuits, over any field. ACM Classification: F.2.1 AMS Classification: 03D15
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عنوان ژورنال:
- Theory of Computing
دوره 7 شماره
صفحات -
تاریخ انتشار 2011