Small-Scale Structure of Spacetime: Bounds and Conjectures
arXiv:0710.3075 · doi:10.1063/1.2902784
Abstract
This review consists of two parts. The first part establishes certain astrophysical bounds on the smoothness of classical spacetime. Some of the best bounds to date are based on the absence of vacuum Cherenkov radiation in ultrahigh-energy cosmic rays. The second part discusses possible implications of these bounds for the quantum structure of spacetime. One conjecture is that the fundamental length scale of quantum spacetime may be different from the Planck length.
20 pages; invited talk at the Third Mexican Meeting on Mathematical and Experimental Physics, September 10-14, 2007, El Colegio Nacional, Mexico City; v3: final version
References in corpus (33)
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- Discreteness of area and volume in quantum gravity
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- Variable VHE gamma-ray emission from Markarian 501
- Detection of a Cosmic Ray with Measured Energy Well Beyond the Expected Spectral Cutoff due to Cosmic Microwave Radiation
- Stability, Causality, and Lorentz and CPT Violation
- Lorentz invariance and quantum gravity: an additional fine-tuning problem?
- Lorentz-Violating Electrostatics and Magnetostatics
- Relativity tests by complementary rotating Michelson-Morley experiments
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- Threshold analyses and Lorentz violation
- An upper limit to the photon fraction in cosmic rays above 10^19 eV from the Pierre Auger Observatory
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- Improved test of Lorentz Invariance in Electrodynamics using Rotating Cryogenic Sapphire Oscillators
- Ultrahigh-energy cosmic-ray bounds on nonbirefringent modified-Maxwell theory
- Spacetime foam, CPT anomaly, and photon propagation
- Limits on Lorentz Violation from the Highest Energy Cosmic Rays
- Bounds on length scales of classical spacetime foam models
- Vacuum Cherenkov radiation in spacelike Maxwell-Chern-Simons theory
- New Bounds on Isotropic Lorentz Violation
- Wave Propagation in Stochastic Spacetimes: Localization, Amplification and Particle Creation
- Merging gauge coupling constants without Grand Unification
- Emergent Relativity
- Emergent Gauge Bosons
- Erratum: New methods of testing Lorentz violation in electrodynamics
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- Fundamental length scale of quantum spacetime foam
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