I assume your city doesn't have rent control, how do rent increases work there? Are they allowed to just send you a notice saying "hey, just fyi your rent is do

I assume your city doesn't have rent control, how do rent increases work there? Are they allowed to just send you a notice saying "hey, just fyi your rent is doubling next year"? If there's a specific tenant they don't like are they allowed to increase their rent by more than others?