Multiple scrum teams can own the same backlog.
Since scrum teams must remain small, sometimes a product team will need to be composed of multiple scrum teams. These teams would share the same product objective, product owner, and product backlog, while independently self-organizing around different sprint goals and increment objectives.rS2
Ken Schwaber and Jeff Sutherland, The Scrum Guide: The Definitive Guide to Scrum: The Rules of the Game, 2020, https://scrumguides.org/docs/scrumguide/v2020/2020-Scrum-Guide-US.pdf. (See notes.)