We develop the interpretation that gravity arises from electromagnetic energy loading of the quantum vacuum, treated as a physical storage medium with vacuum force scale K₀ = c⁴/(8πG). The dimensionless scalar field ψ measures the fractional loading, and the vacuum refractive index n = eᵠ follows uniquely from the multiplicative composition law via Cauchy's exponential functional equation. We interpret the full nonlinear DFD field equation as a stress–strain constitutive equilibrium of the vacuum medium, define gravitational strain and stress in analogy with continuum mechanics, and show that the vacuum exhibits reduced gravitational permittivity at low gradients — the mechanism behind flat rotation curves without dark matter. The constitutive split parameter κ = α/4 ≈ 1.82 × 10⁻³ is derived from gauge-emergence corrections to the optical metric. Newton's constant G = c⁴/(8πK₀) is identified as the inverse vacuum force scale, explaining both its universality and its smallness. The vacuum stiffness is topologically structured, with normalization set by H₀ through K₀ = ℏH₀²/(8πα⁵⁷c). Companion Python module (dfd_gravity.py, 35/35 validation tests passing) included. Parent theory: Density Field Dynamics (DFD) unified theory v3.2, https://doi.org/10.5281/zenodo.18066593Alpha derivation: https://doi.org/10.5281/zenodo.19178465 The Physical Origin of the Refractive Field in Density Field Dynamics: Gravity as Electromagnetic Vacuum Loading | Zenodo Skip to main You are using an outdated browser. Please upgrade your browser to improve your experience. Published March 23, 2026 | Version 1.0 Preprint Open The Physical Origin of the Refractive Field in Density Field Dynamics: Gravity as Electromagnetic Vacuum Loading Authors/Creators Alcock, Gary 1 Show affiliations 1. GTA Companies Description We develop the interpretation that gravity arises from electromagnetic energy loading of the quantum vacuum, treated as a physical storage medium with vacuum force scale K₀ = c⁴/(8πG). The dimensionless scalar field ψ measures the fractional loading, and the vacuum refractive index n = eᵠ follows uniquely from the multiplicative composition law via Cauchy's exponential functional equation. We interpret the full nonlinear DFD field equation as a stress–strain constitutive equilibrium of the vacuum medium, define gravitational strain and stress in analogy with continuum mechanics, and show that the vacuum exhibits reduced gravitational permittivity at low gradients — the mechanism behind flat rotation curves without dark matter. The constitutive split parameter κ = α/4 ≈ 1.82 × 10⁻³ is derived from gauge-emergence corrections to the optical metric. Newton's constant G = c⁴/(8πK₀) is identified as the inverse vacuum force scale, explaining both its universality and its smallness. The vacuum stiffness is topologically structured, with normalization set by H₀ through K₀ = ℏH₀²/(8πα⁵⁷c). Companion Python module (dfd_gravity.py, 35/35 validation tests passing) included. Parent theory: Density Field Dynamics (DFD) unified theory v3.2, https://doi.org/10.5281/zenodo.18066593 Alpha derivation: https://doi.org/10.5281/zenodo.19178465 Files The_Physical_Origin_of_the_Refractive_Field_in_Density_Field_Dynamics__Gravity_as_Electromagnetic_Vacuum_Loading.pdf Files (345.1 kB) Name Size Download all The_Physical_Origin_of_the_Refractive_Field_in_Density_Field_Dynamics__Gravity_as_Electromagnetic_Vacuum_Loading.pdf md5:231f17ceaa20e95afea64018b512ef07 345.1 kB Preview Download Additional details Related works Is supplement to Preprint: 10.5281/zenodo.18066593 (DOI) Preprint: 10.5281/zenodo.19178465 (DOI) 20 Views 12 Downloads Show more details All versions This version Views Total views 20 20 Downloads Total downloads 12 12 Data volume Total data volume 4.5 MB 4.5 MB More info on how stats are collected.... Versions External resources Indexed in OpenAIRE Communities Keywords and subjects Keywords density field dynamics refractive gravity vacuum loading electromagnetic vacuum Newton constant vacuum stiffness MOND modified gravity Cauchy functional equation constitutive relations nonlinear optics analog gravity Sakharov induced gravity scalar field gravity gravitational permittivity dark matter alternative Details DOI DOI Badge DOI 10.5281/zenodo.19200032 Markdown [](https://doi.org/10.5281/zenodo.19200032) reStructuredText ..