We study electromagnetic and gravitational properties of anti–de Seitter (AdS) black shells (also referred to as AdS black bubbles)—a class of quantum gravity motivated black hole mimickers, that in the classical limit are described as ultracompact shells of matter. We find that their electromagnetic properties are remarkably similar to black holes. We then discuss the extent to which these objects are distinguishable from black holes, both for intrinsic interest within the black shell model, and as a guide for similar efforts in other subclasses of exotic compact objects (ECOs). We study photon rings and lensing band characteristics, relevant for very large baseline interferometry (VLBI) observations, as well as gravitational wave observables—quasinormal modes in the eikonal limit and the static tidal Love number for nonspinning shells—relevant for ongoing and upcoming gravitational wave observations. Published by the American Physical Society2025 
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                            Matter waves and clocks do not observe uniform gravitational fields
                        
                    
    
            Abstract In a uniform gravitational field, classical test objects fall universally. Any reference object or observer will fall in the same universal manner. Therefore, a uniform gravitational field cannot create dynamics between observers and classical test objects. The influence of a uniform gravitational field on matter waves and clocks, however, is described inconsistently throughout research and education. To illustrate, we discuss the behavior of a matter-wave interferometer and a clock redshift experiment in a uniform gravitational field. As a consistent formulation of the equivalence principle implies, a uniform gravitational field has no observable influence on these systems and is physically equivalent to the absence of gravity. 
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                            - Award ID(s):
- 2016244
- PAR ID:
- 10589686
- Publisher / Repository:
- Purpose-Led Publishing
- Date Published:
- Journal Name:
- Physica Scripta
- Volume:
- 99
- Issue:
- 4
- ISSN:
- 0031-8949
- Page Range / eLocation ID:
- 046103
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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