Singularity of two-electron density of states and anomalous t-dependence of sc gap of high-tc superconducting crystals

It is shown theoretically that complicated structure of electron bands crossing the Fermi level and presence of features (singularities) in two-electron density of states can give rise to arising deeply inside of band far from ef new coupled states which may also be characterized by SC gap and which are responsible for SC of crystals too. The temperature dependence of both SC gaps as traditional (located near ef) and “new” ones are strongly changed when wave vector of electron pairs increases