Align environment immediately after section break

Question

When I use an align environment immediately after a new section, there is a significantly increased line break between the section and the equation, too large for my taste. Is there a way to make this break the same size as if text were immediately after the section break?

For example:

\documentclass[a4paper]{article}
\usepackage{amsmath}

\begin{document}

\section{F at the critical point}
    \label{sec:1fi}

    \begin{align*}
        F(a)&=\frac{1}{2}
    \end{align*}

    The second derivative test has been to chosen in order to confirm the nature of the critical point:

    \begin{align*}
        F''(a)&=8+\frac{9}{2a^4}+\frac{5}{4a^6}
    \end{align*}

\end{document}

Additionally, there is more space than I would like between the text and the second align, as compared to between the first align and the text.

Answer 1

It turns out that the additional space was caused by the line breaks - commenting these lines out solves this issue (Spacing around align environments). \vspace*{-\baselineskip} is sufficient when the environment follows a section header.