How to list pages from an author?

And add the username to the array

https://codex.wordpress.org/Function_Reference/get_pages  
  <?php $args = array(
        'sort_order' => 'asc',
        'sort_column' => 'post_title',
        'hierarchical' => 1,
        'exclude' => '',
        'include' => '',
        'meta_key' => '',
        'meta_value' => '',
        'authors' => '',
        'child_of' => 0,
        'parent' => -1,
        'exclude_tree' => '',
        'number' => '',
        'offset' => 0,
        'post_type' => 'page',
        'post_status' => 'publish'
    ); 
    $pages = get_pages($args); 
    ?>