Reconciling a quantum gravity minimal length with lack of photon dispersion

Abstract

Generic arguments lead to the idea that quantum gravity has a minimal length scale. A possible observational signal of such a minimal length scale is that photons should exhibit dispersion. In 2009 the observation of a short gamma ray burst seemed to bound the minimal length scale to distances smaller than the Planck length, implying that spacetime appeared continuous to distances below the Planck length. This poses a challenge for such minimal distance models. Here we propose a modification of the position and momentum operators, $\hat{x}$ and $\hat{p}$, which lead to a minimal length scale, but preserve the photon energy-momentum relationship $E=pc$. In this way there is no dispersion of photons with different energies. This can be accomplished without modifying the commutation relationship $[\hat{x},\hat{p}]=i\hslash$.

17 pages and 4 figures. Added references and discussion to address reviewer comments. To be published in PLB

References in corpus (5)

• Universality of Quantum Gravity Corrections
• Deformed Special Relativity and Deformed Symmetries in a Canonical Framework
• A novel mechanism for probing the Planck scale
• A solution to the soccer ball problem for generalised uncertainty relations
• A New Approach to Generalised Uncertainty Relations

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