Theory of Classical Novae

We briefly review the current understanding of classical novae. Nova light curves basically exhibit a homologous nature, beside the dust blackout and oscillatory behavior, in spite of very different evolution timescale from fast to slow novae. Optically thick winds governs the evolution of decay phase of nova outbursts, of which mass-loss rate depends strongly on the white dwarf (WD) mass and weakly on the chemical composition of ejecta. The optical and near-infrared light curves of novae are reproduced mainly by free-free emission from optically thick winds. Ultraviolet (narrow 1455 A band) and supersoft X-ray fluxes are reproduced basically by the blackbody emission from the photosphere. These optical, UV, and supersoft X-ray light curves evolve in different timescales, and we can estimate the WD mass from fitting theoretical light curves to observational data. We also discuss the growth rate of the WD via hydrogen/helium burning for various WD masses and accretion rates.