2012 IEEE 27th Conference on Computational Complexity (2011)

San Jose, California USA

June 8, 2011 to June 11, 2011

ISSN: 1093-0159

ISBN: 978-0-7695-4411-3

pp: 23-33

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/CCC.2011.37

ABSTRACT

In 1997, H{\aa}stad showed $\NP$-hardness of $(1-\eps, 1/q + \delta)$-approximating $\maxthreelin(\Z_q)$; however it was not until 2007 that Guruswami and Raghavendra were able to show $\NP$-hardness of $(1-\eps, \delta)$-approximating $\maxthreelin(\Z)$. In 2004, Khot--Kindler--Mossel--O'Donnell showed $\UG$-hardness of $(1-\eps, \delta)$-approximating $\maxtwolin(\Z_q)$ for $q = q(\eps,\delta)$ a sufficiently large constant; however achieving the same hardness for $\maxtwolin(\Z)$ was given as an open problem in Raghavendra's 2009 thesis.In this work we show that fairly simple modifications to the proofs of the $\maxthreelin(\Z_q)$ and $\maxtwolin(\Z_q)$ results yield optimal hardness results over $\Z$. In fact, we show a kind of ``bicriteria'' hardness: even when there is a $(1-\eps)$-good solution over $\Z$, it is hard for an algorithm to find a $\delta$-good solution over $\Z$, $\R$, or $\Z_m$ for any $m \geq q(\eps,\delta)$ of the algorithm's choosing.

INDEX TERMS

CITATION

Yi Wu,
Yuan Zhou,
Ryan O'Donnell,
"Hardness of Max-2Lin and Max-3Lin over Integers, Reals, and Large Cyclic Groups",

*2012 IEEE 27th Conference on Computational Complexity*, vol. 00, no. , pp. 23-33, 2011, doi:10.1109/CCC.2011.37