darkhistory.utilities.spence_series_diff¶
- darkhistory.utilities.spence_series_diff(b, a)¶
Returns the Taylor series for Li2(b) - Li2(a).
Li2 is the polylogarithm function defined by
\[\begin{split}\\text{Li}_2(z) \\equiv \\sum_{k=1}^\\infty \\frac{z^k}{k^2} \\,.\end{split}\]- Parameters:
- andarray
Input for Li2(a).
- bndarray
Input for Li2(b).
- Returns:
- ndarray
The Taylor series Li2(b) - Li2(a), up to the 11th order term.