4 papers
The Lorentzian Geometry of Tunneling in Global de Sitter at Late Time
Thibaut Coudarchet, Ben Freivogel, Bjoern Hassfeld +1
It is widely believed that Coleman--De Luccia (CDL) instantons characterize tunneling transitions in a de Sitter multiverse. Their most naive interpretation uses analytic continuat…
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…
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…
DeWitt wave functions for de Sitter JT gravity
Wilfried Buchmuller, Arthur Hebecker, Alexander Westphal
Jackiw-Teitelboim (JT) gravity in two-dimensional de Sitter space is an intriguing model for cosmological "wave functions of the universe". Its minisuperspace version already conta…