English

Expectation values of minimum-length Ricci scalar

General Relativity and Quantum Cosmology 2022-03-07 v2

Abstract

In this paper, we consider a specific model, implementing the existence of a fundamental limit distance L0L_0 between (space or time separated) points in spacetime, which in the recent past has exhibited the intriguing feature of having a minimum-length Ricci scalar R(q)R_{(q)} that does not approach the ordinary Ricci scalar RR in the limit of vanishing L0L_0. R(q)R_{(q)} at a point has been found to depend on the direction along which the existence of minimum distance is implemented. Here, we point out that the convergence R(q)RR_{(q)}\to R in the L00L_0\to 0 limit is anyway recovered in a relaxed or generalized sense, which is when we average over directions, this suggesting we might be taking the expectation value of R(q)R_{(q)} promoted to be a quantum variable. It remains as intriguing as before the fact that we cannot identify (meaning this is much more than simply equating in the generalised sense above) R(q)R_{(q)} with RR in the L00L_0\to 0 limit, namely when we get ordinary spacetime. Thing is like if, even when L0L_0 (read here the Planck length) is far too small to have any direct detection of it feasible, the intrinsic quantum nature of spacetime might anyway be experimentally at reach, witnessed by the mentioned special feature of Ricci, not fading away with L0L_0 (i.e. persisting when taking the 0\hbar \to 0 limit).

Cite

@article{arxiv.2010.10063,
  title  = {Expectation values of minimum-length Ricci scalar},
  author = {Alessandro Pesci},
  journal= {arXiv preprint arXiv:2010.10063},
  year   = {2022}
}

Comments

v2: 9 pages; clarification of a point in the discussion of the Lorentz case; added a possible connection with other approaches; it corresponds to the published version; in memory of Prof. Thanu Padmanabhan

R2 v1 2026-06-23T19:28:41.681Z