We present an overview on relational observables in gravity mainly from a loop quantum
gravity perspective. The gauge group of general relativity is the diffeomorphism group of the …

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 …

The standard formulation of quantum theory relies on a fixed space-time metric determining
the localisation and causal order of events. In general relativity, the metric is influenced by …

In general relativity, the description of spacetime relies on idealised rods and clocks, which
identify a reference frame. In any concrete scenario, reference frames are associated to …

We combine the “evolving constants” approach to the construction of observables in
canonical quantum gravity with the Page-Wootters formulation of quantum mechanics with a …

We analyze the nature of the statistics of the work done on or by a quantum many-body
system brought out of equilibrium. We show that, for the sudden quench and for an initial …

One of the most fundamental open problems in physics is the unification of general relativity
and quantum theory to a theory of quantum gravity. An aspect that might become relevant in …

The quantum measurement problem can be regarded as the tension between the two
alternative dynamics prescribed by quantum mechanics: the unitary evolution of the wave …

We discuss some difficulties that arise in attempting to interpret the Page–Wootters and
Internal Quantum Reference Frames formalisms, then use a 'final measurement'approach to …

We have recently developed a new understanding of probability in quantum gravity. In this
paper we provide an overview of this new approach and its implications. Adopting the de …