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REPORTS > KEYWORD > POLYMORPHISMS:
Reports tagged with Polymorphisms:
TR09-059 | 2nd July 2009
Gábor Kun, Mario Szegedy

#### A NEW LINE OF ATTACK ON THE DICHOTOMY CONJECTURE

The well known dichotomy conjecture of Feder and
Vardi states that for every &#64257;nite family &#915; of constraints CSP(&#915;) is
either polynomially solvable or NP-hard. Bulatov and Jeavons re-
formulated this conjecture in terms of the properties of the algebra
P ol(&#915;), where the latter is ... more >>>

TR13-159 | 20th November 2013
Per Austrin, Venkatesan Guruswami, Johan Håstad

#### $(2+\epsilon)$-SAT is NP-hard

Revisions: 2

We prove the following hardness result for a natural promise variant of the classical CNF-satisfiability problem: Given a CNF-formula where each clause has width $w$ and the guarantee that there exists an assignment satisfying at least $g = \lceil \frac{w}{2}\rceil -1$ literals in each clause, it is NP-hard to find ... more >>>

TR16-029 | 7th March 2016
Joshua Brakensiek, Venkatesan Guruswami

#### New hardness results for graph and hypergraph colorings

Finding a proper coloring of a $t$-colorable graph $G$ with $t$ colors is a classic NP-hard problem when $t\ge 3$. In this work, we investigate the approximate coloring problem in which the objective is to find a proper $c$-coloring of $G$ where $c \ge t$. We show that for all ... more >>>

TR18-059 | 6th April 2018
Joshua Brakensiek, Venkatesan Guruswami

#### Combining LPs and Ring Equations via Structured Polymorphisms

Revisions: 1

Promise CSPs are a relaxation of constraint satisfaction problems where the goal is to find an assignment satisfying a relaxed version of the constraints. Several well known problems can be cast as promise CSPs including approximate graph and hypergraph coloring, discrepancy minimization, and interesting variants of satisfiability. Similar to CSPs, ... more >>>

TR20-004 | 17th January 2020
Joshua Brakensiek, Venkatesan Guruswami, Marcin Wrochna, Stanislav Zivny

#### The Power of the Combined Basic LP and Affine Relaxation for Promise CSPs

Revisions: 1

In the field of constraint satisfaction problems (CSP), promise CSPs are an exciting new direction of study. In a promise CSP, each constraint comes in two forms: "strict" and "weak," and in the associated decision problem one must distinguish between being able to satisfy all the strict constraints versus not ... more >>>

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