It is commonly said that
"elementary particles are indeed formed by strings."
(from E Witten interview)
Which equations of string theory show that elementary particles are indeed formed by strings (2d string worldsheets)?
How to see elementary particles in equations of each version of string theory?
- In Type I?
- In Type IIA?
- In Type IIB?
- In Type SO(32)?
- In Type $E_8 \times E_8$?
Can we take electrons and $u,d$ quarks as examples?