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arXiv · 2608.14596

MacDowell-Mansouri ${\sigma}$-model

Egor Pluzhnikov·Stanislav Alexeyev
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Abstract

Standard pre-geometric mechanisms reproduce the {\Lambda}CDM model but lack a natural source for inflation. We propose a mechanism for the emergence of scalar-coupled topological terms by extending the Lie algebra of a MacDowell-Mansouri model to a Lie algebroid. These terms are commonly regarded as a source for cosmological inflation in effective string actions. The theory reduces to the scalar-tensor theory belonging to the Horndeski class, and reproduces inflationary dynamics that meet existing constraints (Planck/BICEP/Keck and GW170817).

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Egor Pluzhnikov, Stanislav Alexeyev. 2026-06-27. MacDowell-Mansouri ${\sigma}$-model. https://arxiv.org/abs/2608.14596

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