How to add author byline below headline

You will want to create a child theme and then modify a copy of the content.php file.

@mannu87 — I had the same question placing the author byline immediately below the blog post title in TwentyFifteen, and created this child theme to do it (and a few other things). Feel free to use or modify as you wish.

https://github.com/JackDougherty/twentyfifteen-child-theme