Fractal properties of particle paths due to generalised uncertainty relations

TL;DR

This paper investigates how generalized and extended uncertainty principles in a quantum geometry model influence the fractal dimensions of particle paths, revealing fundamental differences in their effects on quantum path properties.

Contribution

It introduces a new analysis of Hausdorff dimensions of particle paths within a smeared space quantum geometry model, contrasting with previous GUP studies based on modified commutators.

Findings

Minimum length affects Hausdorff dimension differently than in previous models.

GUP increases the Hausdorff dimension of particle paths, while EUP decreases it.

At coarse resolutions, particle paths have canonical dimensions of 2, but differ at minimum scales.

Abstract

We determine the Hausdorff dimension of a particle path, $D_{\rm H}$, in the recently proposed `smeared space' model of quantum geometry. The model introduces additional degrees of freedom to describe the quantum state of the background and gives rise to both the generalised uncertainty principle (GUP) and extended uncertainty principle (EUP) without introducing modified commutation relations. We compare our results to previous studies of the Hausdorff dimension in GUP models based on modified commutators and show that the minimum length enters the relevant formulae in a different way. We then determine the Hausdorff dimension of the particle path in smeared momentum space, $\tilde{D}_{\rm H}$, and show that the minimum momentum is dual to the minimum length. For sufficiently coarse grained paths, $D_{\rm H} = \tilde{D}_{\rm H} = 2$, as in canonical quantum mechanics. However, as the resolutions approach the minimum scales, the dimensions of the paths in each representation differ, in contrast to their counterparts in the canonical theory. The GUP-induced corrections increase $D_{\rm H}$ whereas the EUP-induced corrections decrease $\tilde{D}_{\rm H}$, relative to their canonical values, and the extremal case corresponds to $D_{\rm H} = 3$, $\tilde{D}_{\rm H} = 1$. These results show that the GUP and the EUP affect the fractal properties of the particle path in fundamentally different, yet complimentary, ways.