Rigorous WKB for finite-order linear recurrence relations with smooth coefficients
Rigorous WKB for finite-order linear recurrence relations with smooth coefficients
复制标题
DOI:
10.1137/s0036141093248037
复制
发表时间:
2006-08
影响因子:
2
通讯作者:
O. Costin;R. Costin
中科院分区:
文献类型:
--
作者:
O. Costin;R. Costin
The $\epsilon \to 0$ behavior of recurrence relations of the type $\sum\nolimits_{j = 0}^l {a_j (k\epsilon ,\epsilon )y_{k + j} = 0} $, $k \in {\bf Z}$ (l fixed) is studied. The $a_j $ are $C^\infty $ functions in each variable on $I \times [0,\epsilon _0 ]$ for a bounded interval I and $\epsilon _0 > 0$. Under certain regularity assumptions we find the asymptotic behavior of the solutions of such recurrences. In typical cases, there exists a fundamental set of solutions in the form $\{ {\exp (\epsilon ^{ - 1} F_m (k\epsilon ,\epsilon ))} \}_{m = 1, \ldots ,l} $, where the functions $F_m $ are $C^\infty $ in each variable on the same domain as the $a_j $, showing in particular that the formal perturbation-series solutions are asymptotic to true solutions of these recurrences. Some applications are also briefly discussed.