We address an issue: would the cosmological scale factor be a locally
oscillating quantity? This problem is examined in the framework of two
classical 1+1-dimensional models: the first one is a string against a curved
background, and the second one is an inhomogeneous Bianchi I model. For the
string model, it is shown that there exist the gauge and the initial condition
providing an oscillation of scale factor against a slowly evolving background,
which is not affected by such an oscillation "at the mean". For the
inhomogeneous Bianchi I model with the conformal time gauge, an initially
homogeneous scale factor can become inhomogeneous and undergo the nonlinear
oscillations. As is shown these nonlinear oscillations can be treated as a
nonlinear gauge wave.Comment: 10 pages, 5 figure
