\documentclass[11pt]{report}
\usepackage{titlesec}


\titleformat{\chapter}[display]
  {\Huge\bfseries}
  {}
  {0pt}
  {\thechapter.\ }
  
\titleformat{name=\chapter,numberless}[display]
  {\Huge\bfseries}
  {}
  {0pt}
  {}
  
\pagenumbering{arabic}

