The conventional formulation of the non-adiabatic (Aharonov-Anandan) phase is based on the equivalence class {eα(t)ψ(t, ~x)}. This equivalence class when understood as defining generalized rays in the Hilbert space is not generally consistent with the superposition principle in interference and polarization phenomena. The hidden local gauge symmetry, which arises from the arbitrariness of the c...

A recently developed perturbation theory for solving self-consistent-eld equations is applied to the hydrogen atom in a strong magnetic eld. This system has been extensively studied using other methods and is therefore a good test case for the new method. The perturbation theory yields summable large-order expansions. The accuracy of the self-consistent-eld approximation varies according to eld...

Even if non-adiabatic perturbations are generated in multi-field inflation, the perturbations will become adiabatic if the universe after inflation enters an era of local thermal equilibrium, with no non-zero conserved quantities, and will remain adiabatic as long as the wavelength is outside the horizon, even when local thermal equilibrium no longer applies. Small initial non-adiabatic perturb...

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Self-consistent particle-in-cell simulations are performed to verify earlier theoretical predictions of adiabatic thermal beams in a periodic solenoidal magnetic focusing field [K. In particular, results are obtained for adiabatic thermal beams that do not rotate in the Larmor ...

We present a gauge-invariant formalism to study the evolution of curvature perturbations in a Friedmann-Robertson-Walker universe filled by multiple interacting fluids. We resolve arbitrary perturbations into adiabatic and entropy components and derive their coupled evolution equations. We demonstrate that perturbations obeying a generalised adiabatic condition remain adiabatic in the large-sca...

We present a general formalism for describing stimulated Raman adiabatic passage in a multilevel atom. The atom is assumed to have two ground state manifolds a and b and an excited state manifold e, and the adiabatic passage is carried out by resonantly driving the a-e and b-e transitions with time-dependent fields. Our formalism gives a complete description of the adiabatic passage process and...

We present a geometrical representation of the process of sum frequency generation in the undepleted pump approximation, in analogy with the known optical Bloch equations. We use this analogy to propose a technique for achieving both high efficiency and large bandwidth in sum frequency conversion using the adiabatic inversion scheme. The process is analogous with rapid adiabatic passage in NMR,...

Abstract This study investigates the determining parameters of thermal comfort office in an arid hot-arid environment Bechar, located northwestern region Algeria, which vertical walls room and roof are subjected to solar irradiations floor is considered be adiabatic. The flux calculated by ASHRAE (American Society Heating, Refrigerating Air-Conditioning Engineers) method. predicted results vali...

Expressions for a K-adiabatic master equation for a bimolecular recombination rate constant krec are derived for a bimolecular reaction forming a complex with a single well or complexes with multiple well, where K is the component of the total angular momentum along the axis of least moment of inertia of the recombination product. The K-active master equation is also considered. The exact analy...