Eddington luminosity as a conditional force balance
For isotropic luminosity L and a constant flux-weighted opacity per mass κ, outward radiative acceleration is κL/(4πr²c).
Key knowledge
For isotropic luminosity L and a constant flux-weighted opacity per mass κ, outward radiative acceleration is κL/(4πr²c). Comparing it with Newtonian GM/r² gives L_Edd=4πGMc/κ. With fully ionized hydrogen and low-energy Thomson scattering, κ is approximately σ_T/m_p when electron mass is neglected. This conditional balance is useful for stars and accretion; it is not a universal maximum observed luminosity.
Values and equations
a_rad=κL/(4πr²c); a_grav=GM/r²; L_Edd=4πGMc/κ
- a_rad,a_grav
- radiative and gravitational acceleration magnitudes m s⁻²
- κ
- flux-weighted opacity per unit matter mass m² kg⁻¹
- L,L_Edd
- isotropic luminosity and conditional balance luminosity W
- r
- distance from central source m
- M
- enclosed gravitating mass kg
- G
- gravitational constant m³ kg⁻¹ s⁻²
- c
- vacuum light speed m s⁻¹
Conditions and scope
- Spherical steady geometry, opacity coupled to the matter, weak-field gravity and the stated flux/opacity model. Radius r is measured from the central source; use consistent local luminosity and enclosed mass.
- Geometry, anisotropy, changing opacity, magnetic confinement, outflows, transients and photon trapping can change interpretation. A large isotropic-equivalent observed luminosity alone does not uniquely determine mass or demonstrate that this model applies.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read the actual electron/proton force balance and its hydrogen-scattering assumptions. Replaced the cross-section-per-pair by explicitly defined flux-weighted opacity per mass; checked SI acceleration dimensions and force cancellation. Excluded blanket maximal steady luminosity across every geometry and dated stellar-mass/galaxy-feedback numerical conclusions.
2026-10-10 · Independent AI editorial review: All44 exact root-authored compact records, equations/variable units/conditions and140 origin edges accepted after independently reading final6/18 with bounded primary bodies and matching prior38/122 scientific fingerprints unchanged. Exact claim/edge review is distinct from combined inventory scope and separate CLE26 approval; no entire cited books or old-corpus experimental revalidation is asserted. Receipt: cosmos-completion-independent-content-and-inventory-review.1.
Entry details
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- uni-cosmos-eddington-force-balance
- Revision
- core.1
- Structured reference record
- University core expansion