Nucleon Axial-Vector Form Factors from Lattice QCD

We present high-statistics results for the nucleon isovector axial form factors from a $2+1+1$-flavor lattice calculation, including 2 ensembles at physical pion mass and 3 lattice spacings. High-statistics estimates allow us to quantify systematic uncertainties in the extraction of $G_A(Q^2)$ with ${\cal M}_A$ estimated to be $1.39(28)$ GeV, which is close to the value obtained by the miniBooNE collaboration ($1.35(17)$ GeV). If time allows, we will also discuss the partially conserved axial current (PCAC) relation in our calculations.