Observation of a gravitational Aharonov-Bohm effect

Gravitational interference The Aharonov-Bohm effect is a quantum mechanical effect in which a magnetic field affects the phase of an electron wave as it propagates along a wire. Atom interferometry exploits the wave characteristic of atoms to measure tiny differences in phase as they take different paths through the arms of an interferometer. Overstreet et al . split a cloud of cold rubidium atoms into two atomic wave packets about 25 centimeters apart and subjected one of the wave packets to gravitational interaction with a large mass (see the Perspective by Roura). The authors state that the observed phase shift is consistent with a gravitational Aharonov-Bohm effect. —ISO

The topological counterparts of non-Hermitian SSH models

Inspired by the relevance between the asymmetric coupling amplitude and the imaginary gauge field, we construct the counterpart of the non-Hermitian SSH model. The idea is the nonzero imaginary magnetic flux vanishing when the boundary condition changes from periodic to open. The zero imaginary magnetic flux of the counterpart leads to the eliminating of the non-Hermitian skin effect and the non-Hermitian Aharonov-Bohm effect which ensures the recovery of the conventional bulk-boundary correspondence from the non-Bloch bulk-boundary correspondence. We explain how some the non-Hermitian models can be transformed to the non-Hermitian SSH models and how the non-reciprocal hopping in the non-Hermitian SSH models can be transformed from one term to the other terms by the similarity transformations. We elaborate why the effective imaginary magnetic flux disappears due to the interplay of the non-reciprocal hoppings in the partner of the non-Hermitian SSH model. As the results, we obtain the topological invariants of the non-Hermitian SSH model in analytical form defined in conventional Brillouin zone. The non-Hermitian SSH model in domain configuration on a chain is discussed with this method. The technique gives an alternative way to study the topological properties of non-Hermitian systems.

Rotating frame effects and potential on a relativistic scalar particle in Kaluza–Klein theory

The effects of uniform rotation on a relativistic scalar particle that interacts with a Cornell-type potential in background space–time described by the Kaluza–Klein theory are analyzed and the gravitational analogue of the Aharonov–Bohm effect is observed. Furthermore, linear confinement of a relativistic scalar particle was also discussed. We see a coupling between the angular velocity of the rotating frame [Formula: see text] and the angular momentum eigenvalue [Formula: see text] which shows the Sagnac-type effect.

Geometric phase for Dirac Hamiltonian under gravitational fields in the nonrelativistic regime

We show the appearance of geometric phase in a Dirac particle traversing in nonrelativistic limit in a time-independent gravitational field. This turns out to be similar to the one originally described as a geometric phase in magnetic fields. We explore the geometric phase in the Kerr and Schwarzschild geometries, which have significant astrophysical implications. Nevertheless, the work can be extended to any spacetime background including that of time-dependent. In the Kerr background, i.e. around a rotating black hole, geometric phase reveals both the Aharonov–Bohm effect and Pancharatnam–Berry phase. However, in a Schwarzschild geometry, i.e. around a nonrotating black hole, only the latter emerges. We expect that our assertions can be validated in both the strong gravity scenarios, like the spacetime around black holes, and weak gravity environment around Earth.

Element Decay

This paper attempts to establish the existence of element decay by making a historical case for the existence of theory decay, a phenomenon where theories leave an agent’s mosaic without any re-evaluation or decision on the agent’s part. The phenomenon of theory decay is to be theoretically distinguished from rejection without replacement; while the latter is a result of an agent’s deliberation, the former is a result of an agent’s inaction. To locate historical instances of theory decay, there should be evidence that the agent under study existed continuously throughout the period under study, that the theory was accepted at some point and unaccepted at some later point, and that the theory left the mosaic without any decision on the part of the agent. With these indicators at hand, I discuss five potentially promising historical cases: Poisson distribution, the Aharonov-Bohm effect, Damascus steel, Greek fire, and Cremonese violins. I argue that there is solid historical evidence to interpret the last case as an instance of element decay, which is sufficient to establish the existence of the phenomenon. I show that element decay is best seen as a non-scientonomic phenomenon; its existence highlights that individual and communal agents have limited capacities of knowledge retention and transmission and, when these limits are reached, element decay often takes place. This suggests that sufficient epistemic capacity to retain and transmit knowledge is a necessary precondition for the existence of scientonomic patterns, which emerge and hold only when the agent has measures in place to counteract potential element decay.

The study of the generalized Klein–Gordon oscillator in the context of the Som–Raychaudhuri space–time

In this paper, we study the relativistic scalar particle described by the Klein–Gordon equation that interacts with the uniform magnetic field in the context of the Som–Raychaudhuri space–time. Based on the property of the biconfluent Heun function equation, the corresponding Klein–Gordon oscillator and generalized Klein–Gordon oscillator under considering the Coulomb potential are separately investigated, and the analogue of the Aharonov–Bohm effect is analyzed in this scenario. On this basis, we also give the influence of different parameters including parameter [Formula: see text] and oscillator frequency [Formula: see text], and the potential parameter [Formula: see text] on the energy eigenvalues of the considered systems.

Aharonov–Bohm effect in a Coulomb-type potential under the influence of a cutoff point

We analyze the influence of a cutoff point on a Coulomb-type potential that stems from the interaction of an electron with electric fields. This cutoff point establishes a forbidden region for the electron. Then, we search for bound state solutions to the Schrödinger equation. In addition, we consider a rotating reference frame. We show that the effects of rotation break the degeneracy of the energy levels. Further, we discuss the Aharonov–Bohm effect for bound states.