4 papers
Localized Gravity, de Sitter, and the Horizon Criterion
Bjoern Hassfeld, Arthur Hebecker, Daniel Schiller
Realizing de Sitter-like solutions in string theory remains challenging, prompting speculation about which specific feature might be responsible for their inconsistency in quantum…
End-of-the-World Branes and Inflationary Predictions for Rocky and Swampy Landscapes
Bjoern Hassfeld, Arthur Hebecker, Alexander Westphal
Making cosmological predictions in a multiverse is a fundamental theoretical challenge. Assuming that (quasi-)de Sitter vacua are quantum mechanically described by a finite-dimensi…
The Boundary Proposal
Bjoern Hassfeld, Arthur Hebecker
One of the leading ideas for the beginning of the Universe is the Hartle-Hawking `No-Boundary Proposal.' Since the Cobordism Conjecture claims that any spacetime allows for a dynam…
Cobordism and Bubbles of Anything in the String Landscape
Bjoern Hassfeld, Arthur Hebecker, Johannes Walcher
We study bubble of nothing decays and their reverse processes, the creation of vacua through `bubbles of something', in models of the Universe based on string theory. From the four…