NINE dimensions??? What a piker.
MY theory is that there are 172 dimensions of space, and Professor Maldacena's model is merely a holographic projection from MY universe.
The excellant book "The Elegant Universe" demonstrates using math how there are 11 dimensions that comprise space-time.
That's just one version of String Theory. There are others. Theories like this depend on "fudge factors" to make them work. ie, made-up mathematical adjustments. Same with Inflation theory. IT attempts to correct the 5 or 6 major flaws with the standard Big Bang theory. Yet it too needs various adjustments for it to even begin to make sense. Many cosmologists dislike or have trouble with both Inflation and String theory for this fudge factor reason.