activity
20242026
collaborators

8 papers

hep-th2026

Quantum nucleation of black hole mimickers via chaos dominated tunneling

Ulf Danielsson, Suvendu Giri, Vyshnav Mohan +1

Black hole mimickers, ultracompact horizonless objects, have been proposed as alternatives to black holes in a variety of settings, including extensions of general relativity and s…

hep-th2026

Weak gravity at micron scales from dark bubble cosmology and its cosmological consequences

Ulf Danielsson, Suvendu Giri

The dark bubble model makes a positive cosmological constant natural in string theory, and predicts several new physical phenomena within reach in the near future. In this paper we…

hep-th2026

Dark bubbles, dark dimensions and fat gravitons

Ulf Danielsson, Suvendu Giri

The dark bubble model explains the existence of a positive cosmological constant by making explicit use of the instabilities underlying the de Sitter swampland conjectures to make…

hep-th2026

Self-gravitating electromagnetic waves in the dark bubble model

Ulf Danielsson, Daniel Panizo, Vincent Van Hemelryck

We construct embeddings of gravitational and electromagnetic waves in the dark bubble scenario using pp-wave geometries in AdS5, motivated by the fact that pp-wave spacetimes often…

hep-th2025

Black Shell Thermodynamics

Ulf Danielsson, Vyshnav Mohan, Larus Thorlacius

Black shells have been proposed as black hole mimickers, i.e. horizonless ultra-compact objects that replace black holes. In this paper, we assume the existence of black shells and…

gr-qc2025

Black hole mimickers: from theory to observation

Cosimo Bambi, Ramy Brustein, Vitor Cardoso +16

The black hole paradigm, while remarkably successful, raises fundamental questions-both classical and quantum-about the nature of spacetime, horizons, and singularities. Black hole…