ARBITRARILY LONG ARITHMETIC PROGRESSIONS FOR CONTINUED FRACTIONS OF LAURENT SERIES

A famous theorem of Szemer＇edi asserts that any subset of integers with posi- tive upper density contains arbitrarily arithmetic progressions. Let Fq be a finite field with q elements and Fq（（X^-1）） be the power field of formal series with coefficients lying in Fq. In this paper, we concern with the analogous Szemeredi problem for continued fractions of Laurent series： we will show that the set of points x ∈ Fq（（X-1）） of whose sequence of degrees of partial quotients is strictly increasing and contain arbitrarily long arithmetic progressions is of Hausdorff dimension 1/2.     

欧拉图与矩阵环的多项式恒等式

本文运用Swan证明Amitsur-levitzki定理所用有向路图论方法，获得了交换环上矩阵环所满足的一类新型多项式恒等式，标准多项式恒等式和Chang-Giambruno-Sehgal多项式恒等式是我们所得恒等式的特例。