I am getting the following error message:
Missing $ inserted. ...bord, le premier phaseur U1 est égal à Ue^
… but I cannot find my mistake. I would therefore appreciate your help !
% !TeX program = lualatex
\documentclass{article}%
\usepackage[utf8x]{inputenc}%
\usepackage{lmodern}%
\usepackage{textcomp}%
\usepackage{lastpage}%
\usepackage[head=1pt,margin=0.3in,bottom=0.3in,includeheadfoot= False]{geometry}%
\usepackage{hyperref}%
\usepackage{bm}
%
\usepackage{needspace}%
\usepackage{textcomp}%
\usepackage{graphicx, array}%
\usepackage{textalpha} % <--- Greek letters in text
%
\usepackage{geometry}
\usepackage{babel}
\usepackage{fontspec}
\usepackage{amssymb} % <---- for real number symbol (R)
\setmainfont{DejaVu Serif}
\setsansfont{DejaVu Sans}
\setmonofont{DejaVu Sans Mono}
\begin{document}%
Ue^{(j$\alpha$ )}. Je laisse volontairement l'angle $\alpha$
\end{document}
EDIT:
I have this:
Ue^(jα)
And I want to automatically transcribe it to Latex code... so I replace all greec letters with their math mode equivalent (i.e. $\alpha$)


Ue^(j$\alpha$ )is not allowed, try$Ue^{(j\alpha )}$instead. There is some room for further improvement.\dotsshould be in math mode, isn't it?$but it does not change it.amsmathand do$\text{Ue}^{(\text{j}\alpha )}$.