A set A of natural numbers is finitely embeddable in another such set B if every finite subset of A has a rightward translate that is a subset of B. This notion of finite embeddability arose in combinatorial number theory, but in this paper we study it in its own right. We also study a related notion of finite embeddability of ultrafilters on the natural numbers. Among other results, we obtain connections between finite embeddability and the algebraic and topological structure of the Stone-Čech compactification of the discrete space of natural numbers. We also obtain connections with nonstandard models of arithmetic.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-ba8024-1-2016, author = {Andreas Blass and Mauro Di Nasso}, title = {Finite Embeddability of Sets and Ultrafilters}, journal = {Bulletin of the Polish Academy of Sciences. Mathematics}, volume = {63}, year = {2015}, pages = {195-206}, zbl = {06545366}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ba8024-1-2016} }
Andreas Blass; Mauro Di Nasso. Finite Embeddability of Sets and Ultrafilters. Bulletin of the Polish Academy of Sciences. Mathematics, Tome 63 (2015) pp. 195-206. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ba8024-1-2016/