I would be interested to read whatever study it is that you're referencing. From my understanding, There is a known limit to the observable universe as light and matter have only expanded and traveled so far since the big band occurred. Studying what lies beyond that is obviously a very difficult task. I have read some articles suggesting there is a portion of the observable universe where it appears matter is moving in a way that suggests something beyond the limit of the observable space pulling it, but I don't remember the article well or how credible the source was.
This is speculation on my part and probably shouldn't be taken too seriously considering my knowledge of cosmology is limited, but I don't think it's entirely improbable that there are other expansions beyond the observable universe. I don't know of any reason to assume the big bang and subsequent formation of the universe was a completely unique event.