On the Second-Order Feasibility Cone: Primal-Dual Representation and Efficient Projection

We study the second-order feasibility cone for given data (M; g). We construct a new representation for this cone and its dual based on the spectral decomposition of the matrix This representation is used to efficiently solve the problem of projecting an arbitrary point which aside from theoretical interest also arises as a necessary subroutine in the re-scaled perceptron algorithm. We develop a method for solving the projection problem to an accuracy whose computational complexity is bounded by operations after the spectral decomposition of is computed. Here the width width denotes the widths of , respectively. This is a substantial improvement over the complexity of a generic interior-point method.

By: Alexandre Belloni; Robert M. Freund

Published in: RC24072 in 2006

LIMITED DISTRIBUTION NOTICE:

This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.

rc24072.pdf

Questions about this service can be mailed to reports@us.ibm.com .