Piotr Berman, Marek Karpinski

Improved inaproximability results are given, including the

best up to date explicit approximation thresholds for bounded

occurence satisfiability problems, like MAX-2SAT and E2-LIN-2,

and problems in bounded degree graphs, like MIS, Node Cover

and MAX CUT. We prove also for the first time inapproximability

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Janka ChlebĂkovĂˇ, Miroslav Chlebik

We study small degree graph problems such as Maximum Independent Set

and Minimum Node Cover and improve approximation lower bounds for

them and for a number of related problems, like Max-B-Set Packing,

Min-B-Set Cover, Max-Matching in B-uniform 2-regular hypergraphs.

For example, we prove NP-hardness factor of 95/94

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Michael Langberg

A $k$-uniform hypergraph $G$ of size $n$ is said to be $\varepsilon$-far from having an independent set of size $\rho n$ if one must remove at least $\varepsilon n^k$ edges of $G$ in order for the remaining hypergraph to have an independent set of size $\rho n$. In this work, ... more >>>

Magnus Bordewich, Martin Dyer, Marek Karpinski

We give a new method for analysing the mixing time of a Markov chain using

path coupling with stopping times. We apply this approach to two hypergraph

problems. We show that the Glauber dynamics for independent sets in a

hypergraph mixes rapidly as long as the maximum degree $\Delta$ of ...
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Venkatesan Guruswami, Ali Kemal Sinop

We prove almost tight hardness results for finding independent sets in bounded degree graphs and hypergraphs that admit a good

coloring. Our specific results include the following (where $\Delta$, assumed to be a constant, is a bound on the degree, and

$n$ is the number of vertices):

Thomas O'Neil

A symmetric representation for a set of objects requires the same amount of space for the set as for its complement. Complexity classifications that are based on the length of the input can depend on whether the representation is symmetric. In this article we describe a symmetric representation scheme for ... more >>>

Amey Bhangale, Subhash Khot

The $2$-to-$2$ Games Theorem of [KMS-1, DKKMS-1, DKKMS-2, KMS-2] implies that it is NP-hard to distinguish between Unique Games instances with assignment satisfying at least $(\frac{1}{2}-\varepsilon)$ fraction of the constraints $vs.$ no assignment satisfying more than $\varepsilon$ fraction of the constraints, for every constant $\varepsilon>0$. We show that the reduction ... more >>>