The series for (g^) includes multipoint correlation functions (pA(qi), pA(qa)), whose behavior in the range of ... we see on the basis of the Gaussian diagrams that perturbation theory can be used only in a limited range to calculate (g^tq, u)). ... the size R~(x) rises rapidly and the parameters /A and fQ become greater than unity, perturbation theory becomes invalid. ... It can be calculated as an expansion in powers of the invariant charge and this results in an effective summation of theanbsp;...

Title | : | Semiconductors |

Author | : | |

Publisher | : | - 1993 |

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