I would guess that they are working out who is going to be "top cat" around the place. For your part, I would just make sure you have some time alone with just the female, some calm time together, even if it is just sitting with her, allowing her to get used to you more. I would make sure you also have "quality time" alone with him, so he knows he is still loved. Perhaps their squabbles will subside ...

Others will chime in, I am sure ...