Are covert and rational adversaries same? Aumann and Lindell defined covert adversaries in 2009 which is informally adversaries which have a epsilon-deterrence to cheat. Some authors (for ex. John R. Wallrabenstein) have defined similar adversaries and called it rational adversaries who act "rationally". I have not seen a simulation-based definition of rational adversaries. 

So, in essence, are covert and rational adversaries same? Can they be used interchangeably?
As the previous answer says, they are certainly NOT the same. However, there is certainly a connection between them. Specifically, the covert model just says that there is a deterrent parameter $\epsilon$ and the guarantee is that if the adversary tries to cheat then it will be caught with probability at least $\epsilon$. The question that arises is how should $\epsilon$ be set in real life.

Here, rationality can be utilized. Specifically, if you are given the adversary's utility when it succeeds in cheating undetected, its (presumably lower) utility when it doesn't cheat, and its (presumably even lower) utility when it is detected cheating, then you can compute the value of $\epsilon$ that will guarantee that the rational choice is to behave honestly. I'll leave the details of how to compute this to you (it's not difficult).