Published online by Cambridge University Press: 22 June 2017
Given a factor code $\unicode[STIX]{x1D70B}$ from a shift of finite type
$X$ onto a sofic shift
$Y$, an ergodic measure
$\unicode[STIX]{x1D708}$ on
$Y$, and a function
$V$ on
$X$ with sufficient regularity, we prove an invariant upper bound on the number of ergodic measures on
$X$ which project to
$\unicode[STIX]{x1D708}$ and maximize the measure pressure
$h(\unicode[STIX]{x1D707})+\int V\,d\unicode[STIX]{x1D707}$ among all measures in the fiber
$\unicode[STIX]{x1D70B}^{-1}(\unicode[STIX]{x1D708})$. If
$\unicode[STIX]{x1D708}$ is fully supported, this bound is the class degree of
$\unicode[STIX]{x1D70B}$. This generalizes a previous result for the special case of
$V=0$ and thus settles a conjecture raised by Allahbakhshi and Quas.