Change the math font style

Hi is there an option to change the font used in mathmode for the whole document in the preamble? I am using the following preamble to write a thesis

\documentclass[%
  english,ngerman,%
  BCOR=6mm,cdgeometry=no,DIV=13%
]{tudscrbook}

\usepackage{isodate}
\usepackage{blindtext}

% Kodierung, Schrift und Sprache auswählen
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[english]{babel}

\deffootnote{1em}{1em}{\textsuperscript{\thefootnotemark }}
% Grafiken, Tabellen, Mathematikumgebungen
\usepackage{graphicx,xcolor}
\usepackage{tabularx}
\usepackage{amsmath,amssymb}
\DeclareMathOperator{\Tr}{tr}       % trace of a matrix
% Darstellung von Fließumgebungen
\usepackage{flafter,afterpage}
\usepackage[section]{placeins}
\usepackage[margin=8mm,font=small,labelfont=bf,format=plain]{caption}
%\usepackage[margin=8mm,font=small,labelfont=bf,format=plain]{subcaption}
\usepackage{subfig}                         % fuer subfloats
%\numberwithin{equation}{chapter}
%\numberwithin{figure}{chapter}
%\numberwithin{table}{chapter}
\usepackage{dsfont}
\usepackage{lipsum}
\usepackage[normalem]{ulem}
\usepackage[square,numbers]{natbib} %[numbers,sort&compress]{natbib}
\usepackage{lmodern}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Ab hier ist Platz für eigene Ergänzungen (Pakete, Befehle, etc.)

%Zitieren
\usepackage[bookmarks=true]{hyperref} 
\hypersetup{colorlinks=true,allcolors=blue}  % blaue Verlinkungen                                       
\usepackage[english,capitalise]{cleveref}           % use capital beginning letters
\usepackage{cmap}                                   % damit man Text aus dem PDF korrekt rauskopieren kann

%\usepackage{caption, booktabs}             % Bildunterschriften

%Quantenmechanik
\usepackage{braket}
\usepackage{float}                               
\usepackage{bm}                                  % for bold small gamma  \textbf{\gamma} -> \bm{\gamma}
\usepackage{mathtools}
% input python code
\usepackage{listings} % %https://en.wikibooks.org/wiki/LaTeX/Source_Code_Listings
\lstset{
    %basicstyle=\ttfamily,
    columns=fullflexible,
    frame=single,
    breaklines=true,
    postbreak=\mbox{\textcolor{red}{$\hookrightarrow$}\space},
}

\newcommand{\avg}[1]{\langle #1 \rangle}

\begin{document}
...
\end{document}

Now if I am trying to write mathematical statements I am presented with the following font:

I would like to change this font to the default mathmode font, but I couldn't find the option in the documentation. How can I change this in the preamble?

tud-cd / tudscr

Change the math font style #81