Approximating integer quadratic programs and MAXCUT in subdense graphs
Author
Summary, in English
Let A be a real symmetric n x n-matrix with eigenvalues, lambda(1),..., lambda(n) ordered after decreasing absolute value, and b an n x 1-vector. We present an algorithm finding approximate solutions to min x*(Ax+b) and maxx*(Ax+b) over x is an element of {-1,1}(n), with an absolute error of at most (c(1) vertical bar lambda(1)vertical bar +vertical bar lambda([c2 log n])vertical bar)2n + O(alpha n + beta) root n log n), where alpha and beta are the largest absolute values of the entries in A and b, respectively, for any positive constants c1 and c2, in time polynomial in n. We demonstrate that the algorithm yields a PTAS for MAXCUT in regular graphs on n vertices of degree d of omega(root n log n), as long as they contain O(d(4) log n) 4-cycles. The strongest previous result showed that Omega(n/log n) average degree graphs admit a PTAS.
Department/s
Publishing year
2005
Language
English
Pages
839-849
Publication/Series
Lecture Notes in Computer Science
Volume
3669
Document type
Journal article
Publisher
Springer
Topic
- Computer Science
Status
Published
ISBN/ISSN/Other
- ISSN: 1611-3349