diff --git a/tex/_optical.tex b/tex/_optical.tex
index 796db8b..330d8f0 100644
--- a/tex/_optical.tex
+++ b/tex/_optical.tex
@@ -72,7 +72,7 @@ \section{Optoelectronic coupling}
   \caption{%
     Optical transition rate matrix elements
     $\left| P_± \right|
-    =\left| \vc{ϵ_±} · P_+^{+ -} \sin {β} \right|$
+    =\left| \vc{ϵ}_± · P_+^{+ -} \sin {β} \right|$
     for \ce{MoSe2}, \ce{WS2}, and \ce{WSe2}.
     Material parameters are given in~\cite{PhysRevLett.108.196802}
     and a gap of $Δ_{\vK} = \SI{7.5}{\milli\electronvolt}$
diff --git a/tex/_topology.tex b/tex/_topology.tex
index 677c1cf..8b297f0 100644
--- a/tex/_topology.tex
+++ b/tex/_topology.tex
@@ -2,7 +2,7 @@ \section{Berry curvature}
 
 The Berry curvature in the parent crystal
 for left and right-circularly polarized
-($\vc{ϵ_±}$) optical excitations for a given $\vK$
+($\vc{ϵ}_±$) optical excitations for a given $\vK$
 is $± 2 Ω_{+ ↑}^+ \of{k}$, where
 \begin{subequations}
   \begin{align}