Schwarzschild exterior and coordinate horizon
Research context
postgraduate concept · conditional · As of 2026-10-10
The asymptotically flat, spherical vacuum exterior has ds²=−(1−r_s/r)c²dt²+(1−r_s/r)⁻¹dr²+r²dΩ², r_s=2GM/c².
Key knowledge
The asymptotically flat, spherical vacuum exterior has ds²=−(1−r_s/r)c²dt²+(1−r_s/r)⁻¹dr²+r²dΩ², r_s=2GM/c². Schwarzschild t,r coordinates are singular at the horizon; regular coordinates extend through it. The r=0 curvature singularity is a different issue; stellar interiors, rotation, charge or external matter require other metrics.
Values and equations
r_s=2GM/c²; ds²=−(1−r_s/r)c²dt²+dr²/(1−r_s/r)+r²dΩ²
- r_s,r
- Schwarzschild and areal radii m
- t
- Static coordinate time s
- M
- Asymptotic mass kg
- G
- Gravitational constant m³ kg⁻¹ s⁻²
- c
- Light speed m s⁻¹
- ds²
- Metric interval m²
- dΩ²
- Dimensionless unit-sphere angular metric
Conditions and scope
- Vacuum spherical geometry, zero cosmological constant, positive mass and exterior r>r_s for the displayed static chart.
- M is the gravitational mass seen asymptotically and r is areal radius; coordinate-time delays are not direct local clock readings.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Inspected §§6.1–6.1.4: Schwarzschild exterior, Birkhoff assumptions, coordinate horizon and regular extensions; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication.
2026-10-10 · Author source inspection of the displayed claim, model assumptions and equations; independent exact-content and branch-inventory review is a separate gate. Contemporary status is a dated snapshot, not a promise of ongoing monitoring.
Entry details
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