I'm trying to get a hold of the Casper FFG paper and I suddenly realized I have a very basic question about validators in PoS.
At any given time, the entire network has an active validator set. It is commonly said that every validator can "vote" with the weight depending on how much the validator "stakes".
But wealth is chain dependent: an account may have different balances in different chains.
So it seems to me that a validator can only vote in the branch of his "deposit/staking transaction" to the system.
But then, what does the "total deposit" mean, and how is "weight" calculated?