Title
An improved lower bound for approximating minimum GCD multiplier in l∞ norm (GCDM∞)
Abstract
In this paper, we study the inapproximability of the following NP-complete number theoretic optimization problems introduced by Rossner and Seifert [C. Rossner, J.P. Seifert, The complexity of approximate optima for greatest common divisor computations, in: Proceedings of the 2nd International Algorithmic Number Theory Symposium, ANTS-II, 1996, pp. 307-322]: Given n numbers a"1,...,a"n@?Z, find an @?"~-minimum GCD multiplier for a"1,...,a"n, i.e., a vector x@?Z^n with minimum max"1"@?"i"@?"n|x"i| satisfying @?"i"="1^nx"ia"i=gcd(a"1,...,a"n). We show that assuming PNP, it is NP-hard to approximate the Minimum GCD Multiplier in @?"~ norm (GCDM"~) within a factor n^c^/^l^o^g^l^o^g^n for some constant c0 where n is the dimension of the given vector. This improves on the best previous result. The best result so far gave 2^(^l^o^g^n^)^^^1^^^-^^^@e factor hardness by Rossner and Seifert [C. Rossner, J.P. Seifert, The complexity of approximate optima for greatest common divisor computations, in: Proceedings of the 2nd International Algorithmic Number Theory Symposium, ANTS-II, 1996, pp. 307-322], where @e0 is an arbitrarily small constant.
Year
DOI
Venue
2008
10.1016/j.tcs.2007.09.030
Theoretical Computer Science
Keywords
DocType
Volume
greatest common divisor computation,n number,approximate optimum,best result,International Algorithmic Number Theory,factor n,J.P. Seifert,minimum GCD multiplier,C. Rossner,factor hardness
Journal
396
Issue
ISSN
Citations 
1-3
0304-3975
0
PageRank 
References 
Authors
0.34
8
3
Name
Order
Citations
PageRank
Wenbin Chen142.19
Jiangtao Meng242.19
Dengpan Yin3463.64