Deploying and Maintaining a Multiuser Geodatabase is Esri Training's multiuser geodatabase course for ArcGIS 10.3. These are questions which required further research before answering.
Q: Is operating system (OS) authentication supported in geodatabases on PostgreSQL?
A: At the moment, no it is not. There are requests from the user community to support it and some research into what it would take to support it has been done, but in the current release of the enterprise geodatabase (ArcGIS 10.3) on PostgreSQL OS authentication is not supported.
