Dimensionful deformations of Poincare' symmetries for a Quantum Gravity without ideal observers

TL;DR

This paper explores how quantum gravity may lead to dimensionful deformations of Poincare' symmetries, challenging classical device assumptions and impacting experimental approaches in quantum gravity research.

Contribution

It introduces the idea that quantum gravity could cause dimensionful symmetry deformations, questioning classical device assumptions in quantum experiments.

Findings

Classical devices cannot behave classically in quantum gravity.

Limitations on observable measurements are linked to classical device assumptions.

Dimensionful deformations of Poincare' symmetries are relevant in quantum gravity phenomena.

Abstract

Quantum Mechanics is revisited as the appropriate theoretical framework for the description of the outcome of experiments that rely on the use of classical devices. In particular, it is emphasized that the limitations on the measurability of (pairs of conjugate) observables encoded in the formalism of Quantum Mechanics reproduce faithfully the ``classical-device limit'' of the corresponding limitations encountered in (real or gedanken) experimental setups. It is then argued that devices cannot behave classically in Quantum Gravity, and that this might raise serious problems for the search of a class of experiments described by theories obtained by ``applying Quantum Mechanics to Gravity.'' It is also observed that using heuristic/intuitive arguments based on the absence of classical devices one is led to consider some candidate Quantum-Gravity phenomena involving dimensionful deformations of the Poincare' symmetries.