Eric J. Pap
YOU?
Author Swipe
View article: Frames of Group Sets and Their Application in Bundle Theory
Frames of Group Sets and Their Application in Bundle Theory Open
We study fiber bundles where the fibers are not a group G but a free G-space with disjoint orbits. The fibers are then not torsors but disjoint unions of these; hence, we like to call them semi-torsors. Bundles of semi-torsors naturally ge…
View article: On the Geometry of Adiabatic Quantum Mechanics
On the Geometry of Adiabatic Quantum Mechanics Open
The adiabatic theorem states that if the Hamiltonian of a quantum system is changed sufficiently slowly, then its instantaneous eigenstates are preserved. In this context, if the original Hamiltonian is restored at the end of the experimen…
View article: A Unified View on Geometric Phases and Exceptional Points in Adiabatic Quantum Mechanics
A Unified View on Geometric Phases and Exceptional Points in Adiabatic Quantum Mechanics Open
We present a formal geometric framework for the study of adiabatic quantum mechanics for arbitrary finite-dimensional non-degenerate Hamiltonians. This framework generalizes earlier holonomy interpretations of the geometric phase to non-cy…
View article: Frames of group-sets and their application in bundle theory
Frames of group-sets and their application in bundle theory Open
We study fiber bundles where the fibers are not a group $G$, but a free $G$-space with disjoint orbits. These bundles closely resemble principal bundles, hence we call them semi-principal bundles. The study of such bundles is facilitated b…
View article: Comment on 'Winding around non-Hermitian singularities' by Zhong et al., Nat. Commun. 9, 4808 (2018)
Comment on 'Winding around non-Hermitian singularities' by Zhong et al., Nat. Commun. 9, 4808 (2018) Open
In a recent paper entitled "Winding around non-Hermitian singularities" by Zhong et al., published in Nat. Commun. 9, 4808 (2018), a formalism is proposed for calculating the permutations of eigenstates that arise upon encircling (multiple…
View article: Non-Abelian nature of systems with multiple exceptional points
Non-Abelian nature of systems with multiple exceptional points Open
The defining characteristic of an exceptional point (EP) in the parameter space of a family of operators is that, upon encircling the EP, eigenstates are permuted. When one encircles multiple EPs, the question arises how to properly compos…