DataTau is what I recommend. Even though there's a lot of posting of how to learn basic data science and so forth, occasionally papers from ArXiv on physics and math concepts show up. End of the day, the content that shows up is a function of the community, which is small. Since it is small, it's not difficult to influence the type of content posted. I guarantee you if you and a few colleagues start posting more about research related topics, they will surface well.