# Pick a specific solution of string theory?

This is a conceptual question. One popular criticism against String Theory is its high number of solutions, around $10^{500}$.

• Is it true that each solution is corresponding to a specific possible universe?

• If yes, can we identify and pick a single solution that is corresponding to our universe?

• If yes, can we use this solution to make testable/falsifiable prediction in our universe?

Please also point out what is possibly wrong in my fact and thinking process.

Is it true that each solution is corresponding to a specific possible universe?

This is looking it backwards. One looks at all these vacua for solutions that fit our current cosmological observations, which is a single one out of this huge number.

If yes, can we identify and pick a single solution that is corresponding to our universe?

Researchers are trying but have not been able to do so. Look at this talk , page 23:

To summarize the status of the string landscape as a “top-down” concept which leads to candidate vacua, EFT,(effective field theory) and predictions,

Classification and calculational techniques are moderately well developed but by no means a mature subject.

In addition people have suggested other relevant classes of 4d vacua (e.g.nonsupersymmetric), and in studying cosmology one may need to understand vacua with other numbers of large dimensions. So this is definitely a work in progress.

On the other hand, the string landscape is a mathematically well-defined structure, someday even rigorously so, and eventually we will understand it