RT Journal Article
T1 An extended Agassi model: algebraic structure, phase diagram, and large size limit
A1 García Ramos, José Enrique
A1 Dukelsky, J.
A1 Pérez Fernández, Pedro
AB The Agassi model (Agassi 1968 Nucl. Phys. A 116 49) is a schematic two-level model that involves pairing and monopole–monopole interactions. It is, therefore, an extension of the well known Lipkin–Meshkov–Glick model (Lipkin et al 1965 Nucl. Phys. 62 188). In this paper we review the algebraic formulation of an extension of the Agassi model as well as its bosonic realization through the Schwinger representation. Moreover, a mean-field approximation for the model is presented and its phase diagram discussed. Finally, a 1/j analysis, with j proportional to the degeneracy of each level, is worked out to obtain the thermodynamic limit of the ground state energy and some order parameters from the exact Hamiltonian diagonalization for finite—j.
PB IOP Publishing
SN 0031-8949
SN 1402-4896 (electrónico)
YR 2019
FD 2019
LK http://hdl.handle.net/10272/16020
UL http://hdl.handle.net/10272/16020
LA eng
NO García-Ramos, J. E., Dukelsky, J., Pérez-Fernández, P., & Arias, J. (2019). An extended Agassi model: algebraic structure, phase diagram, and large size limit. Physica Scripta, 94(4), 44003. https://doi.org/10.1088/1402-4896/aafc6d
NO This work has been supported by the Spanish Ministerio de Economia y Competitividad and the European regional development fund (FEDER) under Projects No. FIS2017-88410-88410-P, FIS2014-53448-C2-2-P and FIS2015-63770-P, and by Consejeria de Economia, Innovacion, Ciencia y Empleo de la Junta de Andalucia (Spain) under Group FQM-160 and FQM-370.
DS Repositorio Institucional de la Universidad de Huelva
RD 17 jun 2026