Supersymmetry and String Theory

[Golfer]

I am reading Michael Hines new book, Supersymmetry and String Theory. He keeps referring to "tree-level". What is this?

 

[jhh]

"Tree-level" refers to Feynman diagrams with no loops. That is, 0th order in perturbation theory (h-bar).

 

[Entropia]

Supersymmetry and String Theory are two theoretical frameworks that have been developed in an attempt to unify the fundamental forces of nature. Supersymmetry proposes the existence of a symmetry between particles with different spin, while String Theory suggests that particles are actually tiny strings vibrating at different frequencies.

In terms of the "tree-level" concept mentioned in Michael Hines' book, this refers to a specific type of calculation or approximation used in theoretical physics. At the tree-level, only the simplest Feynman diagrams (which represent the interactions between particles) are considered, neglecting more complex interactions. This approach is often used in the early stages of research, as it provides a simplified understanding of the underlying theory before more advanced calculations are performed.

Overall, Supersymmetry and String Theory are both highly complex and fascinating areas of study, and their potential implications for our understanding of the universe are still being explored.