Scalar Factor

einsteinpy.utils.scalar_factor.scalar_factor(t, era='md', tuning_param=1.0)[source]

Acceleration of the universe in cosmological models of Robertson Walker Flat Universe.

Parameters:
  • era (string) – Can be chosen from ‘md’ (Matter Dominant), ‘rd’ (Radiation Dominant) and ‘ded’ (Dark Energy Dominant)

  • t (s) – Time for the event

  • tuning_param (float, optional) – Unit scaling factor, defaults to 1

Returns:

Value of scalar factor at time t.

Return type:

float

:raises ValueError : If era is not ‘md’ , ‘rd’, and ‘ded’.:

einsteinpy.utils.scalar_factor.scalar_factor_derivative(t, era='md', tuning_param=1.0)[source]

Derivative of acceleration of the universe in cosmological models of Robertson Walker Flat Universe.

Parameters:
  • era (string) – Can be chosen from ‘md’ (Matter Dominant), ‘rd’ (Radiation Dominant) and ‘ded’ (Dark Energy Dominant)

  • t (s) – Time for the event

  • tuning_param (float, optional) – Unit scaling factor, defaults to 1

Returns:

Value of derivative of scalar factor at time t.

Return type:

float

:raises ValueError : If era is not ‘md’ , ‘rd’, and ‘ded’.: