Title
Small-Set Expansion in Shortcode Graph and the 2-to-2 Conjecture.
Abstract
Dinur, Khot, Kindler, Minzer and Safra (2016) recently showed that the (imperfect completeness variant of) Khotu0027s 2 to 2 games conjecture follows from a combinatorial hypothesis about the soundness of a certain Grassmanian agreement tester. In this work, we show that the hypothesis of Dinur et. al. follows from a conjecture we call the Inverse Shortcode Hypothesis characterizing the non-expanding sets of the degree-two shortcode graph. We also show the latter conjecture is equivalent to a characterization of the non-expanding sets in the Grassman graph, as hypothesized by a follow-up paper of Dinur et. al. (2017). Following our work, Khot, Minzer and Safra (2018) proved the Inverse Shortcode Hypothesis. Combining their proof with our result and the reduction of Dinur et. al. (2016), completes the proof of the 2 to 2 conjecture with imperfect completeness. Moreover, we believe that the shortcode graph provides a useful view of both the hypothesis and the reduction, and might be useful in extending it further.
Year
Venue
DocType
2018
Electronic Colloquium on Computational Complexity (ECCC)
Journal
Volume
Citations 
PageRank 
25
2
0.38
References 
Authors
4
3
Name
Order
Citations
PageRank
Boaz Barak12563127.61
Pravesh Kothari220322.17
David Steurer393444.91