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  • Letter
  • Open Access

Mechanical cosmology: Simulating scalar fluctuations in expanding universes using synthetic mechanical lattices

Brendan Rhyno1,*, Ivan Velkovsky1, Peter Adshead2, Bryce Gadway1,3, and Smitha Vishveshwara1,†

  • *Contact author: brhyno2@illinois.edu
  • †Contact author: smivish@illinois.edu
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Phys. Rev. Research 7, L022004 – Published 3 April, 2025

DOI: https://doi.org/10.1103/PhysRevResearch.7.L022004

Abstract

Inspired by recent advances in observational astrophysics and continued explorations in the field of analog gravity, we discuss the prospect of simulating models of cosmology within the context of synthetic mechanical lattice experiments. We focus on the physics of expanding universe scenarios described by the Friedmann-Lemaître-Robertson-Walker (FLRW) metric. Specifically, quantizing scalar fluctuations in a background FLRW spacetime leads to a quadratic bosonic Hamiltonian with temporally varying pair production terms. Here we present a mapping that provides a one-to-one correspondence between these classes of cosmology models and feedback-coupled mechanical oscillators. As proof of principle, we then perform experiments on a synthetic mechanical lattice composed of such oscillators. We simulate two different FLRW expansion scenarios with universes dominated by vacuum energy and matter and discuss our experimental results.

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Phys. Rev. Research 7, L022004– Published 3 April, 2025
  • Received 7 February 2024
  • Revised 23 September 2024
  • Accepted 27 February 2025
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