I. On a theorem of khintchine
Published online by Cambridge University Press: 24 October 2008
Let θ > 0 and α ≠ 0 be real numbers, and let θ be irrational. Khintchine has shown, by the use of continued fractions, that there is an infinite number of pairs of positive integers (p, q) which satisfy the inequality
for any given K > 5−½; and, more recently, Jogin has shown the same is still true with K = 5−½. The condition that p and q shall be positive is, of course, essential, as otherwise there is the classical result K = ¼ due to Minkowski.
* Khintchine, A., Math. Ann. 111 (1935), 631–7.CrossRefGoogle Scholar
† Jogin, I. I., Uchenye Zapiski Moskov Gos. Univ. Matematika, 73 (1944), 37–40;Google Scholar as quoted in Math. Rev. 7 (1946), 274.Google Scholar
‡ This has recently been improved by Khintchine, , Bull. Acad. Sci. U.R.S.S. 10 (1946), 281–93.Google Scholar Khintchine's results are easily proved by my present methods, and in a subsequent paper of this series I shall show how they can be both generalized and sharpened.
* Hurwitz, , Math. Ann. 39 (1891), 279–81.CrossRefGoogle Scholar See also Hardy, G. H. and Wright, E. M., An Introduction to the Theory of Numbers (Oxford, First edition, 1938; Second edition, 1945),Google Scholar § 11·8. We shall quote this book as Hardy-Wright.
† Hardy-Wright, § 11·10. Koksma, J. F., ‘Diophantische Approximationen’, Ergebn. Math. 4, no. 4 (Springer, Berlin, 1936), pp. 29Google Scholar et.seq.
* A. Khintchine, loc. cit.
* O(0, 0) is not an inner point of
† See diagram. is bounded by the thick line.