Lectures on Naturalness, String Landscape and Multiverse

Understand

The cosmological constant and electroweak hierarchy problem have been a great inspiration for research.

• Nevertheless, the resolution of these two naturalness problems remains mysterious from the perspective of a low-energy effective field theorist.
• The string theory landscape and a possible string-based multiverse offer partial answers, but they are also controversial for both technical and conceptual reasons.
• The present lecture notes, suitable for a one-semester course or for self-study, attempt to provide a technical introduction to these subjects.