We develop the classical theory of Diophantine approximation without assuming monotonicity or convexity. A complete 'multiplicative' zero-one law is established akin to the 'simultaneous' zero-one laws of Cassels and Gallagher. As a consequence we are able to establish the analogue of the Duffin-Schaeffer theorem within the multiplicative setup. The key ingredient is the rather simple but nevertheless versatile 'cross fibering principle'. In a nutshell it enables us to 'lift' zero-one laws to higher dimensions.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-aa160-2-1, author = {Victor Beresnevich and Alan Haynes and Sanju Velani}, title = {Multiplicative zero-one laws and metric number theory}, journal = {Acta Arithmetica}, volume = {161}, year = {2013}, pages = {101-114}, zbl = {1292.11085}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-aa160-2-1} }
Victor Beresnevich; Alan Haynes; Sanju Velani. Multiplicative zero-one laws and metric number theory. Acta Arithmetica, Tome 161 (2013) pp. 101-114. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-aa160-2-1/