Sample interview questions: How do you approach the problem of hierarchy in string theory?
Sample answer:
1. Landscape and Anthropic Principle:
- The vast landscape of string theory vacua provides a natural explanation for the hierarchy problem.
- The anthropic principle suggests that we live in a universe that is compatible with the existence of intelligent life, which favours certain values for the fundamental constants.
- This approach allows for a wide range of possible values for the Higgs mass and other parameters, making the hierarchy problem less severe.
2. Extra Dimensions and Warping:
- The existence of extra spatial dimensions can provide a geometrical explanation for the hierarchy.
- The warping of these extra dimensions can create a hierarchy of scales, with the Planck scale at the highest level and the electroweak scale at a much lower level.
- This approach is often studied in the context of Randall-Sundrum models and AdS/CFT correspondence.
3. Supersymmetry and Hidden Sectors:
- Supersymmetry can provide a solution to the hierarchy problem by relating bosons and fermions, which can cancel out their contributions to the Higgs mass.
- However, supersymmetry has not been observed experimentally, and it may be broken at a high energy scale.
- Hidden sectors in string theory can also play a role in stabilizing the Higgs mass and addressing the hierarchy problem.
4. String Duality and Flux Compactifications:
- String theory duality symmetries can relate different string vacua with different physical properties.
- Flux compactifications, where certain fields are turned on in the extra dimensions, can lead to a variety of effective field theories with different values for the fundamental constants.
- This approach allows for the possibility of finding a vacuum that solves the hier… Read full answer