Elastic Mapping Question for Nested List of Objects

Hi,

I am trying to upload data to an Elastic index. The each document can have many authors associated with it. How should I structure the mapping for this index so that authors will contain a list of first and last names?

Pseudo code:

    "authors_list" : {
        [
            "first_name": {
                "type" : "keyword"
            },
            "last_name": {
                "type" : "keyword"
            },
            "position": {
                "type" : "keyword"
            },
            "organization": {
                "type" : "keyword"
            }
        ]
      }