Title
Robust approximate zeros
Abstract
Smale’s notion of an approximate zero of an analytic function f: C →C is extended to take into account the errors incurred in the evaluation of the Newton operator. Call this stronger notion a robust approximate zero.. We develop a corresponding robust point estimate for such zeros: we prove that if z0∈ C satisfies α(f,z0)z0 is a robust approximate zero, with the associated zero z* lying in the closed disc ${\overline B}(z_{0},\frac{0.07}{f,z_{0}}$. Here α(f,z), γ(f,z) are standard functions in point estimates. Suppose f(z) is an L-bit integer square-free polynomial of degree d. Using our new algorithm, we can compute an n-bit absolute approximation of z*∈IR starting from a bigfloat z0, in time O[dM(n+d2(L+lg d)lg(n+L))], where M(n) is the complexity of multiplying n-bit integers.
Year
DOI
Venue
2005
10.1007/11561071_77
ESA
Keywords
Field
DocType
n-bit integer,stronger notion,point estimate,n-bit absolute approximation,corresponding robust point estimate,approximate zero,robust approximate zero,l-bit integer square-free polynomial,bigfloat z0,c satisfies,satisfiability,analytic function,point estimation
Integer,Discrete mathematics,Combinatorics,Pointer machine,Polynomial,Analytic function,Operator (computer programming),Mathematics,Newton's method
Conference
Volume
ISSN
ISBN
3669
0302-9743
3-540-29118-0
Citations 
PageRank 
References 
7
0.49
11
Authors
3
Name
Order
Citations
PageRank
Vikram Sharma122920.35
Zilin Du2231.95
Chee-Keng Yap31996395.32