Crystal clear lessons on the microstructure of space-time and modified gravity

Abstract

We argue that a microscopic structure for space-time such as that expected in a quantum foam scenario, in which microscopic wormholes and other topological structures should play a relevant role, might lead to an effective metric-affine geometry at larger scales. This idea is supported by the role that microscopic defects play in crystalline structures. With an explicit model we show that wormhole formation is possible in a metric-affine scenario, where the wormhole and the matter fields play a role analogous to that of defects in crystals. We also point out that in metric-affine geometries Einstein's equations with an effective cosmological constant appear as an attractor in the vacuum limit for a vast family of theories of gravity. This illustrates how lessons from solid state physics can be useful in unveiling the properties of the microcosmos and defining new avenues for modified theories of gravity.

7 pages; some minor corrections added

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Cited by in corpus (6)

• Unveiling the Dynamics of the Universe
• Metric-Affine Gravity and Cosmology/Aspects of Torsion and non-Metricity in Gravity Theories
• Fundamental Symmetries and Spacetime Geometries in Gauge Theories of Gravity: Prospects for Unified Field Theories
• Nonsingular black holes in Palatini extensions of General Relativity
• Palatini gravity with nonmetricity, torsion, and boundaries in metric and connection variables
• Non-metricity signatures on the Higgs boson signal strengths at the LHC