The only requirement the actor model demands is that actors only have access to their own data but how actors are scheduled is up to the runtime. It could be that Erlang/BEAM does pin actors to a single thread and then pins those threads to a single core but it is not 100% necessary.
nonetheless, the BEAM does do that, and only revokes actors from a core under certain conditions (power saving). Also it's important to note that the BEAM is not "the actor model" so it is not bound by the requirements thereof, it just "looks like an actor if you squint at it a little bit".
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The only requirement the actor model demands is that actors only have access to their own data but how actors are scheduled is up to the runtime. It could be that Erlang/BEAM does pin actors to a single thread and then pins those threads to a single core but it is not 100% necessary.
nonetheless, the BEAM does do that, and only revokes actors from a core under certain conditions (power saving). Also it's important to note that the BEAM is not "the actor model" so it is not bound by the requirements thereof, it just "looks like an actor if you squint at it a little bit".