documentclass[11pt,a4paper]{report}
usepackage[utf8]{inputenc}
usepackage{authblk}
usepackage[colorinlistoftodos]{todonotes}
date{}
usepackage{amsmath}
usepackage{amssymb}
usepackage{bm}
usepackage[margin=1.2in]{geometry}
usepackage{graphicx}
usepackage{float}
usepackage{caption}
usepackage{subcaption}
usepackage{multicol}
usepackage{xcolor}
numberwithin{equation}{section}
usepackage{epstopdf}
usepackage{enumitem}
usepackage{titlesec}
usepackage{setspace}
usepackage{indentfirst}
doublespacing
%singlespacing
bibliographystyle{plain}
usepackage[superscript]{cite}


titleformat{part}[display]{normalfonthugebfseries}{}{1pt}{}
titleformat{chapter}[display]{centeringnormalfontLargebfseries}{}{1pt}{}
titleformat{section}[display]{normalfontlargebfseries}{}{1pt}{}

begin{document}
part{Abstract}
Hello world
end{document}