Fushchich, V. I.; Shtelen, V. M. On approximate symmetry and approximate solutions of the nonlinear wave equation with a small parameter. (English) Zbl 0711.35086 J. Phys. A, Math. Gen. 22, No. 18, L887-L890 (1989). Summary: The concept of approximate symmetry is introduced. We describe all nonlinearities F(u) with which the nonlinear wave equation \(\square u+\lambda u^ 3+\epsilon F(u)=0\) with a small parameter \(\epsilon\) is approximately scale and conformally invariant. Some approximate solutions of wave equations in question are obtained using the approximate symmetry. Cited in 3 ReviewsCited in 39 Documents MSC: 35L70 Second-order nonlinear hyperbolic equations Keywords:approximate symmetry; nonlinear wave equation; conformally invariant PDFBibTeX XMLCite \textit{V. I. Fushchich} and \textit{V. M. Shtelen}, J. Phys. A, Math. Gen. 22, No. 18, L887--L890 (1989; Zbl 0711.35086) Full Text: DOI Link