pystein.gravity module

Symbolic expressions related to gravitation

This module largely serves as a convenience wrapper around the matter and curvature modules, in that it equates those quantities for fixed components.

pystein.gravity.einstein_equation(mu: int, nu: int, metric: pystein.metric.Metric, stress_energy: Optional[sympy.matrices.dense.MutableDenseMatrix] = None) → sympy.core.expr.Expr

Compute the einstein equation for coordinates mu and nu. Note that this function assumes a perfect fluid for the matter component. In future work this component will be modular.

Parameters

• mu – int, the lower left index of the Einstein and Stress-Energy Tensors

• nu – int, the lower right index of the Einstein and Stress-Energy Tensors

• metric – Metric

Returns

Expr, the Einstein field equation for specific coordinates mu and nu