StressEnergyTensor

Stress-energy-momentum tensor from the Einstein field equations.

class gravica.stress_energy.StressEnergyTensor(einstein, cosmological_constant=None)

Bases: object

Stress-energy-momentum tensor from the Einstein field equations.

\[T_{ab} = \frac{1}{8\pi G}\bigl(G_{ab} + \Lambda\,g_{ab}\bigr)\]

When \(\Lambda = 0\) (default), simplifies to \(T_{ab} = G_{ab} / (8\pi G)\).

The result is expressed with an overall factor of \(1/(8\pi G)\), represented by the symbol _8piG_inv. For vacuum solutions the components are exactly zero regardless of this prefactor.

classmethod from_metric(metric, cosmological_constant=None)

Build from a MetricTensor.

Return type:

StressEnergyTensor

property components: list[list[Expression]]

\(8\pi G\,T_{ab}\) indexed as [a][b].