LaTeX Forum

\documentclass{scrreprt}

\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage{mathtools}%lädt amsmath und weitere

\begin{document}
\noindent normal: \(\alpha\)\\
fett: \(\boldsymbol{\alpha}\)\\
fett: \boldmath\(\alpha\)\unboldmath\ normal: \(\alpha\)
\end{document}

\documentclass[
fontsize=12pt,
ngerman,
captions=tableheading,
headsepline,
twoside=semi,
bibliography=totoc,
]{scrreprt}

\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage[autostyle]{csquotes}
\usepackage{dejavu}
\usepackage{sansmathfonts}
\usepackage{tgheros}
\renewcommand{\familydefault}{\sfdefault}
\usepackage{microtype}
\usepackage[onehalfspacing]{setspace}
\usepackage[automark]{scrlayer-scrpage}
\clearpairofpagestyles
\ihead{\leftmark}
\ohead{\pagemark}
\setkomafont{pageheadfoot}{\scshape}
\renewcaptionname{ngerman}\figurename{Abb.}
\renewcaptionname{ngerman}\tablename{Tab.}
\usepackage{amsmath}
\usepackage{textgreek}
\usepackage[locale=DE]{siunitx}
\usepackage{graphicx}
\graphicspath{{grafiken/}}
\usepackage{subcaption}
\usepackage{tikz}
\usetikzlibrary{shapes, arrows.meta, positioning, fit, backgrounds}
\usepackage{booktabs}
\usepackage{longtable}
\usepackage{enumitem}
\setlist{noitemsep}
\usepackage{listings}
\lstset{basicstyle=\scriptsize\ttfamily, numbers=left, frame=single, tabsize=3}
\usepackage[backend=biber, style=alphabetic]{biblatex}
\usepackage{pdfpages}
\BeforeTOCHead[toc]{\pdfbookmark[1]{\contentsname}{toc}}
\usepackage{hyperref}
\usepackage{cleveref}

\begin{document}
\noindent normal: $\alpha$\\
fett: $\mathbf{\alpha}$
\end{document}