We, far any natural 𝑛, construct an N𝑛-free abelian groups which have few homomorphisms to ℤ. For this we use "N𝑛-free (𝑛 + 1)-dimensional black boxes". The method is hopefully relevant to other constructions of N𝑛-free abelian groups.
@article{1592, title = {Nn-free abelian group with no non-zero homomorphism to Z}, journal = {CUBO, A Mathematical Journal}, volume = {9}, year = {2007}, language = {en}, url = {http://dml.mathdoc.fr/item/1592} }
Shelah, Saharon. Nɴ-free abelian group with no non-zero homomorphism to ℤ. CUBO, A Mathematical Journal, Tome 9 (2007) 21 p. http://gdmltest.u-ga.fr/item/1592/