TY - JOUR
T1 - Partition regularity with congruence conditions
AU - Barber, Ben
AU - Leader, Imre
PY - 2013
Y1 - 2013
N2 - 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 x i is a multiple of some given d i ? 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.
AB - 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 x i is a multiple of some given d i ? 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.
UR - http://www.mendeley.com/catalogue/partition-regularity-congruence-conditions
U2 - 10.4310/joc.2013.v4.n3.a1
DO - 10.4310/joc.2013.v4.n3.a1
M3 - Article
SN - 2156-3527
VL - 4
SP - 293
EP - 297
JO - Journal of Combinatorics
JF - Journal of Combinatorics
IS - 3
ER -