For any collection of graphs we find the minimal dimension d such that the product is embeddable into (see Theorem 1 below). In particular, we prove that (K₅)ⁿ and are not embeddable into , where K₅ and are the Kuratowski graphs. This is a solution of a problem of Menger from 1929. The idea of the proof is a reduction to a problem from so-called Ramsey link theory: we show that any embedding , where O is a vertex of (K₅)ⁿ, has a pair of linked (n-1)-spheres.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm179-3-1, author = {Mikhail Skopenkov}, title = {Embedding products of graphs into Euclidean spaces}, journal = {Fundamenta Mathematicae}, volume = {177}, year = {2003}, pages = {191-198}, zbl = {1051.57032}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm179-3-1} }
Mikhail Skopenkov. Embedding products of graphs into Euclidean spaces. Fundamenta Mathematicae, Tome 177 (2003) pp. 191-198. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm179-3-1/