Check out Cardano's papers. Its PoS protocol has been live on mainnet for a while. Native token support just rolled out to mainnet yesterday and smart contracts are coming in Q2 this year.
It was founded by ETH co-founder Charles, who formed an academia network of CS PhD researchers to deal with 3rd gen blockchain problems and solutions.
It is 3rd gen blockchain built to handle the problems of ethereum and other blockchains that came prior.
A very simple summary is that it's a fairly traditional consensus protocol, in which if anyone breaks the rules it's possible to prove who did it and penalize them by burning their stake. It achieves scale by using aggregated signatures.
