Nuclear polaron beyond the mean-field approximation
نویسندگان
چکیده
منابع مشابه
Boson-fermion Model beyond Mean-field Approximation
A model of hybridized bosons and fermions is studied beyond the mean field approximation. The divergent boson self-energy at zero temperature makes the Cooper pairing of fermions impossible. The frequency and momentum dependence of the self-energy and the condensation temperature T c of initially localized bosons are calculated analytically. The value of the boson condensation temperature T c i...
متن کاملComment on “ Boson - fermion model beyond the mean - field approximation ”
In a recent paper [Alexandrov A S 1996 J. Phys.: Condens. Matter 8 6923–32; cond-mat/9603111], it has been suggested that there is no Cooper pairing in boson-fermion models of superconductivity. We show that this conjecture is based on an inconsistent approximation that violates an exact identity. Quite generally, the divergence of the fermion t-matrix (the Thouless criterion) is accompanied by...
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An explicit expression for the generating functional of two–flavor low–energy QCD with external sources in the presence of non-vanishing nucleon densities has been derived recently [1]. Within this approach we derive power counting rules for the calculation of in-medium pion properties. We develop the so-called standard rules for residual nucleon energies of the order of the pion mass and a mod...
متن کاملNambu-Jona-Lasinio models beyond the mean-field approximation.
Inspired by the model of Nambu and Jona-Lasinio, various Lagrangians are considered for a system of interacting quarks. Employing standard techniques of many-body theory, the scalar part of the quark self-energy is calculated including terms up to second-order in the interaction. Results obtained for the single-particle Green’s function are compared with those which only account for the mean-fi...
متن کاملBeyond the mean field approximation for spin glasses.
We study the d-dimensional random Ising model using a suitable type of BethePeierls approximation in the framework of the replica method. We take into account the correct interaction only inside replicated clusters of spins. Our ansatz is that the interaction of the borders of the clusters with the external world can be described via an effective interaction among replicas. The Bethe-Peierls mo...
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ژورنال
عنوان ژورنال: Physical Review B
سال: 2017
ISSN: 2469-9950,2469-9969
DOI: 10.1103/physrevb.95.245209