Title
Improved Inapproximability of Rainbow Coloring.
Abstract
A rainbow $q$-coloring of a $k$-uniform hypergraph is a $q$-coloring of the vertex set such that every hyperedge contains all $q$ colors. prove that given a rainbow $(k - 2lfloor sqrt{k}rfloor)$-colorable $k$-uniform hypergraph, it is NP-hard to find a normal $2$-coloring. Previously, this was only known for rainbow $lfloor k/2 rfloor$-colorable hypergraphs (Guruswami and Lee, SODA 2015). also study a generalization which we call rainbow $(q, p)$-coloring, defined as a coloring using $q$ colors such that every hyperedge contains at least $p$ colors. We prove that given a rainbow $(k - lfloor sqrt{kc} rfloor, k- lfloor3sqrt{kc} rfloor)$-colorable $k$ uniform hypergraph, it is NP-hard to find a normal $c$-coloring for any $c = o(k)$. The proof of our second result relies on two combinatorial theorems. One of the theorems was proved by Sarkaria (J. Comb. Theory. 1990) using topological methods and the other theorem we prove using a generalized Borsuk-Ulam theorem.
Year
DOI
Venue
2020
10.5555/3381089.3381179
SODA '20: ACM-SIAM Symposium on Discrete Algorithms Salt Lake City Utah January, 2020
Field
DocType
Volume
Discrete mathematics,Combinatorics,Rainbow coloring,Computer science
Conference
abs/1810.02784
Citations 
PageRank 
References 
0
0.34
0
Authors
3
Name
Order
Citations
PageRank
per austrin118718.31
Amey Bhangale2106.71
Aditya Potukuchi301.01