ON A СOMBINATORIAL APPLICATION OF ULTRAFILTER THEORY: A NEW CONSTRUCTION OF TRIANGLE-FREE GRAPHS WITH ARBITRARILY LARGE CHROMATIC NUMBER

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Abstract

The paper describes a new method for constructing triangle-free graphs with an arbitrarily large chromatic number. The method is substantiated using properties of various types of ultrafilter extensions of functions and predicates.

About the authors

N. L Polyakov

HSE University

Email: npolyakov@hse.ru
Moscow, Russia

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