Nonobservable space dimensions and the discreteness of time☆

A. Boyarsky, Paweł Góra

Andreas Fring, M. H. Y. Moussa

It has been argued that it is incompatible to maintain unitary time evolution for time-dependent non-Hermitian Hamiltonians when the metric operator is explicitly time dependent. We demonstrate here that the time-dependent Dyson equation and the time-dependent quasi-Hermiticity relation can be solved consistently in such a scenario for a time-dependent Dyson map and time-dependent metric operator, respectively. These solutions are obtained at the cost of rendering the non-Hermitian Hamiltonian to be a nonobservable operator as it ceases to be quasi-Hermitian when the metric becomes time dependent.

Iégor Reznikoff

Rodolfo Gambini, Jorge A. Pullin

Hanna, Edward

In 1965, Feynman wrote of using a lattice containing one dimension of space and one dimension of time to derive aspects of quantum mechanics. Instead of summing the behavior of all possible paths as he did, this paper will consider the motion of single particles within this discrete Space-Time lattice, sometimes called Feynman's Checkerboard. This empirical approach yielded several predicted emergent properties for a discrete Space-Time lattice, one of which is novel and testable.

Norio Konno, Shohei Koyama

The quantum walk was introduced as a quantum counterpart of the random walk and has been intensively studied since around 2000. Its applications include topological insulators, radioactive waste reduction, and quantum search. The first author in 2019 defined a time-series model based on the measure of the ``discrete-time" and ``discrete-space" quantum walk in one dimension. Inspired by his model, this paper proposes a new model for the graph of a function of a single variable determined by the measure which comes from the weak limit measure of a ``continuous-time or discrete-time" and ``discrete-space" walk. The measure corresponds to a ``continuous-time" and ``continuous-space" walk in one dimension. Moreover, we also presents a method of a linear extrapolation for the graph by our model.