\documentclass[a4paper]{article}
%\usepackage{simplemargins}

%\usepackage[square]{natbib}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}

\begin{document}
\pagenumbering{gobble}

\begin{center}
\vspace{1cm}
\large{
Title of talk\\
Speaker Name 1$^1$}\\
\normalsize{Joint work with Author Name 2$^2$ }\\ %please delete this line if there are no other authors

\hspace{10pt}

\small  
$^1$) Author Name 1 affiliation\\ %please write your affiliation here
AuthorName1@email.com\\ %please write your email here
$^2$) Author Name 2 affiliation %please write your co-author's affiliations if any. If you have more than one co-author, you can add more lines of this type.
\end{center}

\hspace{10pt}

\normalsize

Please replace this sentence with your short abstract.

\end{document}