Can I bring an umbrella inside the arena

I don't know. It's not about metal or not metal thing. It's about safe. Bringing some object that can hurt other person won't be allowed. The best thing is search in the site administration.

You cannot bring them into the Maverick center because they can be used as an object to be thrown, so you should contact the Vivint Center box office

I'm sure you can. They have metal detectors but it shouldn't be a problem

I don't see why not. Although I would either call or check the website to verify that you can.

They do have metal detectors at the entrance and they check bags and the like. I'm sure they would allow to take umbrellas into the arena, but they would certainly check it out.