tardis.transport.montecarlo.nonhomologous_grid module

tardis.transport.montecarlo.nonhomologous_grid.depressed_quartic(leading_coefficient: float, cubic_coefficient: float, quadratic_coefficient: float, linear_coefficient: float, constant_coefficient: float) → tuple[float, float, float, float][source]

Return the real roots of a quartic and NaN for complex roots.

The polynomial is normalized before it is depressed, then factored into two quadratics using a real solution of its resolvent cubic.

Parameters:

leading_coefficientfloat: Coefficient of the fourth-degree term.
cubic_coefficientfloat: Coefficient of the third-degree term.
quadratic_coefficientfloat: Coefficient of the second-degree term.
linear_coefficientfloat: Coefficient of the first-degree term.
constant_coefficientfloat: Constant term.

Returns:

tuple of float: Four real roots or NaN placeholders for non-real roots.

tardis.transport.montecarlo.nonhomologous_grid.solve_resonance_quartic(line_velocity: float, impact_parameter_squared: float, velocity_intercept: float) → tuple[float, float, float, float][source]

Solve the structured quartic for line-resonance ray coordinates.

A projected_position root satisfies:

(projected_position - line_velocity)**2 * (
    projected_position**2 + impact_parameter_squared
) == velocity_intercept**2 * projected_position**2

Parameters:

line_velocityfloat: Target line-resonance projected velocity, scaled by the shell velocity difference.
impact_parameter_squaredfloat: Squared ray impact parameter, scaled by the squared shell width.
velocity_interceptfloat: Intercept of the shell’s linear radial velocity law, scaled by the shell velocity difference.

Returns:

tuple of float: Four dimensionless signed ray-coordinate roots or NaN placeholders for non-real roots.