Recent Explorations Between Landscape and Swampland
Prof. Dr. Arthur Hebecker (University of Heidelberg)

I will start with a brief introduction to the UV-problems of gravity and how string theory proposes to resolve them. As we will see, this implies extra dimensions and hence the possibility of different "compactifications", leading to very many possible 4d theories. The idea that more or less any 4d model can be found in this huge "Landscape" has more recently been challenged by the "Swampland" paradigm, proposing to search for general criteria for what can or can not occur in 4d effective theories having a consistent UV completion in quantum gravity. I will discuss some of the most important such "Swampland Conjectures": The "No-Global Symmetries", "Weak Gravity" and "Distance Conjecture". Finally, I will briefly review the phenomenologically very important but less established "de Sitter Conjecture".