remove author and date header line to save space

Question

I would like to remove the header line of author and date to save space. I try to set the font size to 0, but it does't work

current org file:

#+LATEX_CLASS: beamer

#+LaTeX_CLASS_OPTIONS: [aspectratio=169]
# The following line gives access to the C-c C-b key for headings
#+BEAMER_THEME: CambridgeUS
#+BEAMER_FONT_THEME: structurebold
#+startup: beamer
#+options: toc:nil
#+AUTHOR: author
#+DATE: 5/10
#+BEAMER_HEADER: \graphicspath{{.}}
#+BEAMER_HEADER: \setbeamercolor{frametitle}{bg=grey!20}
#+BEAMER_HEADER: \insertshortauthor \insertshortdate \author[]{}

#+BEAMER_HEADER: \setbeamercolor*{author in head/foot}{}
#+BEAMER_HEADER: \setbeamercolor*{title in head/foot}{}
#+BEAMER_HEADER: \setbeamercolor*{date in head/foot}{}
#+BEAMER_HEADER: \setbeamercolor*{section in head/foot}{}
#+BEAMER_HEADER: \setbeamercolor*{subsection in head/foot}{}

#+BEAMER_HEADER: \setbeamerfont{author in head/foot}{}
#+BEAMER_HEADER: \setbeamerfont{date in head/foot}{}

* hello beamer
** line 1                                                          :B_block:
** line 2
** line 3

Output:

Answer 1

Just set AUTHOR and DATE in your Org mode file to be empty:

...
#+startup: beamer
#+options: toc:nil
#+AUTHOR:
#+DATE:
#+BEAMER_HEADER: \graphicspath{{.}}
#+BEAMER_HEADER: \setbeamercolor{frametitle}{bg=grey
...