Radiation–matter exchange in relativistic accretion
Research context
research method · conditional · As of 2026-10-10
Radiation-GRMHD couples the matter-plus-magnetic stress tensor to a radiation tensor with opposite four-force sources, so their sum is covariantly conserved.
Key knowledge
Radiation-GRMHD couples the matter-plus-magnetic stress tensor to a radiation tensor with opposite four-force sources, so their sum is covariantly conserved. KORAL uses M1 closure and semi-implicit treatment of stiff radiation exchange; the closure approximates angular transport and does not preserve arbitrary intersecting beams.
Values and equations
∇_μ T^(μν) = G^ν; ∇_μ R^(μν) = -G^ν; ∇_μ (T^(μν)+R^(μν)) = 0
- T^(μν)
- Matter-plus-magnetic stress-energy tensor in declared c=1 units
- R^(μν)
- Radiation stress-energy tensor in the same units
- G^ν
- Radiation four-force density transferred to matter; positive sign denotes gain by matter
- ∇_μ
- Covariant derivative for the chosen metric
Conditions and scope
- Use c=1, one metric/sign convention, declared absorption/scattering opacities and a fixed-background spacetime; self-gravity and frequency-resolved nonthermal radiation require extensions.
- Boundary/horizon fluxes and geometric source terms belong in diagnostic budgets. Local total conservation does not imply constant integrated coordinate energy under every metric or boundary condition.
- Conservative matter–radiation exchange, no omitted external four-force, and a specified closure and opacity model; all tensor indices use the same metric.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Numerical simulations of super-critical black hole accretion flows in general relativity: Sections 2.1–2.4 and 3.1–3.3: matter/radiation four-force exchange, M1 closure, opacity and semi-implicit source treatment; accepted-method context (selected source body inspected).
2026-10-10 · Bounded source check of the recorded statement and conditions. This does not certify a unique physical model, reproduce the cited study or replace independent branch review.
Entry details
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- research-earth-radiation-grmhd-budget
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- research.1
- Structured reference record
- Postgraduate & research reference