Abstract
An infinite integer matrix A is called image partition regular if, whenever the natural numbers are finitely coloured, there is an integer vector x such that Ax is monochromatic. Given an image partition regular matrix A, can we also insist that each variable xi is a multiple of some given di? This is a question of Hindman, Leader and Strauss. Our aim in this short note is to show that the answer is negative. As an application, we disprove a conjectured equivalence between the two main forms of partition regularity, namely image partition regularity and kernel partition regularity.
Original language | English |
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Pages (from-to) | 293-297 |
Number of pages | 5 |
Journal | Journal of Combinatorics |
Volume | 4 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2013 |
Keywords
- partition regular systems
- Ramsey theory