Fastest universe expansion and why?

I know that the Universe has expanded many times faster than the speed of light exspecially during Cosmic Inflation 13.7 billion years ago, but I am wondering what the fastest speed that the Universe has ever expanded is, and what is the fastest...

theoretical speed that the Universe can expand? Also what causes the Univerese to expand so fast, basically how is the scalar field created when gravity and the strong nuclar force breaks off from the electoweak force? Can anyone explain this to me, because I am so confused?

600,000,000,000,000,000,000,000,000,000,000,000,000 per a minute is the fastest the universe is thought to have increased. That is only if you are not in the vantage point to view this speed. You can google this, but I have a feeling you just want to show off.

No actually I don't want to show off. I am just a curious people so the number you say 600 Undecillion per minute, what is that referring to 600 Undecillion miles per minute, lightyears per minute, parasecs per minute. You quote the relatively large number 600 Undecillion but what unit are you talking about Kilometers, Miles, Au's, Lightyears, Parsecs, Megaparsecs, Gigaparsecs, Teraparsecs?