Gallegos, A.; Rosu, H. C. Comment on “Demystifying the constancy of the Ermakov-Lewis invariant for a time-dependent oscillator”. (English) Zbl 1392.34032 Mod. Phys. Lett. A 33, No. 24, Article ID 1875001, 3 p. (2018). Summary: We show that a simple modification of the Lagrangian proposed by T. Padmanabhan [ibid. 33, No. 7–8, Article ID 1830005, 5 p. (2018; Zbl 1383.34055)] leads to the most general dynamical invariant in [J. R. Ray and J. L. Reid, “More exact invariants for the time-dependent harmonic oscillator”, Phys. Lett. A 71, No. 4, 317–318 (1979; doi:10.1016/0375-9601(79)90064-1)]. Cited in 5 Documents MSC: 34C14 Symmetries, invariants of ordinary differential equations 34C15 Nonlinear oscillations and coupled oscillators for ordinary differential equations 81T99 Quantum field theory; related classical field theories Keywords:parametric oscillator; Ermakov-Lewis invariant; Ray-Reid invariant Citations:Zbl 1383.34055 PDFBibTeX XMLCite \textit{A. Gallegos} and \textit{H. C. Rosu}, Mod. Phys. Lett. A 33, No. 24, Article ID 1875001, 3 p. (2018; Zbl 1392.34032) Full Text: DOI arXiv References: [1] Padmanabhan, T., Mod. Phys. Lett. A, 33, 1830005, (2018) · Zbl 1383.34055 [2] Ray, J. R.; Reid, J. L., Phys. Lett. A, 71, 317, (1979) [3] Mancas, S. C.; Rosu, H. C., Phys. Lett. A, 378, 2113, (2014) [4] Ray, J. R.; Reid, J. L., Phys. Lett. A, 26, 1042, (1982) [5] Leach, P. G. L., J. Math. Phys., 22, 465, (1981) [6] Cariglia, M.; Galajinsky, A.; Gibbons, G. W.; Horvathy, P. A., Eur. Phys. J. C, 78, 314, (2018) [7] Gelfand, I. M.; Fomin, S. V.; Silverman, R. A., Calculus of Variations, (1963), Prentice-Hall This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.