The problem of time in quantum gravity calls for a relational solution. Using quantum
reduction maps, we establish a previously unknown equivalence between three approaches …

We have previously shown that three approaches to relational quantum dynamics—
relational Dirac observables, the Page-Wootters formalism and quantum deparametrizations …

In this short review paper, relative evolution in time and related issues are analyzed within
classical and quantum mechanics. We first discuss the basics of quantum frames of …

We propose a special relativistic framework for quantum mechanics. It is based on
introducing a Hilbert space for events. Events are taken as primitive notions (as customary in …

The operational approach to time is a cornerstone of relativistic theories, as evidenced by
the notion of proper time. In standard quantum mechanics, however, time is an external …

We describe a method of construction of gauge-invariant operators (Dirac observables or
“evolving constants of motion”) from the knowledge of the eigenstates of the gauge …

In the past few decades, researchers have created a veritable zoo of quantum algorithm by
drawing inspiration from classical computing, information theory, and even from physical …

We consider a global quantum system (the “Universe”) satisfying a double constraint, both
on total energy and total momentum. Generalizing the Page and Wootters quantum clock …

The conventional phase space of classical physics treats space and time differently, and this
difference carries over to field theories and quantum mechanics (QM). In this paper, the …

Time in quantum mechanics is peculiar: it is an observable that cannot be associated to an
Hermitian operator. As a consequence it is impossible to explain dynamics in an isolated …