摘要:We derive Wiman’s asymptotic formula for the number of generalized zeros of (nontrivial) solutions of a second order dynamic equation on a time scale. The proof is based on the asymptotic representation of solutions via exponential functions on a time scale. By using the Jeffreys et al. approximation we prove Wiman’s formula for a dynamic equation on a time scale. Further we show that using the Hartman-Wintner approximation one can derive another version of Wiman’s formula. We also prove some new oscillation theorems and discuss the results by means of several examples. MSC:34E20, 34N05.
关键词:dynamic equation on a time scale ; oscillation theory ; number of zeros ; asymptotic representation of solutions ; Jeffreys, Wentzel, Kramers and Brillouin approximation