RT Journal Article T1 Adiabatic invariants for the regular region of the Dicke model A1 Bastarrachea Magnani A.; R, M. A. A1 Relaño Pérez, Armando A1 Lerma Hernández, S. A1 López del Carpio, B. A1 Chávez Carlos, J. A1 Hirsch, J. G. AB Adiabatic invariants for the non-integrable Dicke model are introduced. They are shown to provide approximate second integrals of motion in the energy region where the system exhibits a regular dynamics. This low-energy region, present for any set of values of the Hamiltonian parameters is described both with a semiclassical and a full quantum analysis in a broad region of the parameter space. Peres lattices in this region exhibit that many observables vary smoothly with energy, along distinct lines which beg for a formal description. It is demonstrated how the adiabatic invariants provide a rationale to their presence in many cases. They are built employing the Born-Oppenheimer approximation, valid when a fast system is coupled to a much slower one. As the Dicke model has one bosonic and one fermionic degree of freedom, two versions of the approximation are used, depending on which one is the faster. In both cases a noticeably accord with exact numerical results is obtained. The employment of the adiabatic invariants provides a simple and clear theoretical framework to study the physical phenomenology associated to these regimes, far beyond the energies where a quadratic approximation around the minimal energy configuration can be used. PB IOP Publishing Ltd SN 1751-8113 YR 2017 FD 2017-04-07 LK https://hdl.handle.net/20.500.14352/18083 UL https://hdl.handle.net/20.500.14352/18083 LA eng NO © 2017 IOP Publishing Ltd. AR is supported by Spanish Grants No. FIS2012-35316 and FIS2015-63770-P (MINECO/FEDER), MAB-M, SL-H, BLC, JC-C and JGH acknowledge financial support from Mexican CONACyT project CB166302 and DGAPA-UNAM project IN109417. SL-H acknowledges financial support from Mexican CONACyT project CB2015-01/255702 and from CONACyT fellowship program for sabbatical leaves. NO Ministerio de Economía y Competitividad (MINECO) NO Mexican CONACyT project NO DGAPA-UNAM project NO CONACyT fellowship program DS Docta Complutense RD 13 abr 2025