In 1941, R. J. Duffin and A. C. Schaeffer conjectured that for the inequality |α - m/n| < ψ(n)/n with g.c.d.(m,n) = 1, there are infinitely many solutions in positive integers m and n for almost all α ∈ ℝ if and only if . As one of partial results, in 1978, J. D. Vaaler proved this conjecture under the additional condition . In this paper, we discuss the metric theory of Diophantine approximation over the imaginary quadratic field ℚ(√d) with a square-free integer d < 0, and show that a Vaaler type theorem holds in this case.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-aa170-1-3, author = {Zhengyu Chen}, title = {On metric theory of Diophantine approximation for complex numbers}, journal = {Acta Arithmetica}, volume = {168}, year = {2015}, pages = {27-46}, zbl = {1337.11046}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-aa170-1-3} }
Zhengyu Chen. On metric theory of Diophantine approximation for complex numbers. Acta Arithmetica, Tome 168 (2015) pp. 27-46. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-aa170-1-3/