This paper is concerned with oscillation theory for selfadjoint second-order scalar dynamic equations of the form
on time scales . Here, a time scale is an arbitrary nonempty closed subset of the real numbers, denoted as measure chain by the authors, stands for the -derivative of and is the composition of with the forward jump operator . Furthermore, are assumed to be rd-continuous.
The authors provide Kamenev-type and interval oscillation criteria for such linear dynamic equations on time scales. These criteria generalize corresponding theorems for ODEs by Ch. G. Philos [Arch. Math. 53, 482–492 (1989; Zbl 0661.34030)] or the second author [J. Math. Anal. Appl. 229, 258–270 (1999; Zbl 0924.34026)], respectively, and are new for difference equations in particular. The paper closes with four examples illustrating the obtained results, two of them for difference equations and one on a time scale with unbounded graininess.