Five regimes of fusion reactions in dense stellar matter

Five regimes of nuclear burning of matter in dense stellar plasma are discussed. They are weakly screening thermonuclear, strongly screening thermonuclear, pycnonuclear, thermally excited pycnonuclear, and intermediate pycno-thermonuclear regimes. The uncertainties of nuclear reaction rates in these regimes are analyzed; astrophysical applications are outlined, with the emphasis on nuclear reactions under extreme conditions in white dwarfs and neutron stars.