Source code for einsteinpy.symbolic.predefined.minkowski
from sympy import diag, sin, symbols
from einsteinpy.symbolic import constants
from einsteinpy.symbolic.metric import MetricTensor
[docs]def MinkowskiCartesian(c=constants.c):
"""
Minkowski(flat) space-time in Cartesian coordinates. Space-time without any curvature or matter.
Parameters
----------
c : ~sympy.core.basic.Basic or int or float
Any value to assign to speed of light. Defaults to 'c'.
"""
coords = symbols("t x y z")
metric = diag(-1, 1 / (c ** 2), 1 / (c ** 2), 1 / (c ** 2)).tolist()
return MetricTensor(metric, coords, "ll", name="MinkowskiMetric")
Minkowski = MinkowskiCartesian
[docs]def MinkowskiPolar(c=constants.c):
"""
Minkowski(flat) space-time in Polar coordinates. Space-time without any curvature or matter.
Parameters
----------
c : ~sympy.core.basic.Basic or int or float
Any value to assign to speed of light. Defaults to 'c'.
"""
coords = symbols("t r theta phi")
t, r, th, ph = coords
c2 = c ** 2
metric = diag(-1, 1 / c2, (r ** 2) / c2, (r ** 2 * sin(th) ** 2) / c2).tolist()
return MetricTensor(metric, coords, "ll", name="MinkowskiMetricPolar")