De Felice, Antonio Doll, Andreas Larrouturou, François Mukohyama, Shinji

In the context of the recently proposed type-II minimally modified gravity theory, i.e. a metric theory of gravity with two local physical degrees of freedom that does not possess an Einstein frame, we study spherically symmetric vacuum solutions to explore the strong gravity regime. Despite the absence of extra degrees of freedom in the gravity se...

Jedamzik, Karsten Pogosian, Levon Zhao, Gong-Bo

The mismatch between the locally measured expansion rate of the universe and the one inferred from the cosmic microwave background measurements by Planck in the context of the standard $\Lambda$CDM, known as the Hubble tension, has become one of the most pressing problems in cosmology. A large number of amendments to the $\Lambda$CDM model have bee...

Häfner, Dietrich Mokdad, Mokdad Nicolas, Jean-Philippe

We show asymptotic completeness for the massive charged Dirac equation between the black hole and Cauchy horizons of a sub-extremal ((Anti-) De Sitter) Reissner-Nordstr\"om black hole.

Gan, Wen-Cong Santos, Nilton O. Shu, Fu-Wen Wang, Anzhong

In this paper we systematically study a five-parameters class of spherically symmetric loop quantum black/white hole solutions, and find that only three independent combinations are physical and uniquely determine the spacetime properties. After exploring the whole 3-dimensional (3D) phase space, we find that the model has very rich physics, and de...

Oliveri, Roberto Speziale, Simone
Published in
General Relativity and Gravitation

Varying the gravitational Lagrangian produces a boundary contribution that has various physical applications. It determines the right boundary terms to be added to the action once boundary conditions are specified, and defines the symplectic structure of covariant phase space methods. We study general boundary variations using tetrads instead of th...

Kuntz, Adrien

We show that the introduction of two worldline parameters defines a different approach to computations in the effective field theory approach to the two-body problem in General Relativity and present some preliminary evidence for a reduction in computational complexity. These parameters obey a polynomial equation whose perturbative expansion recove...

Diggle, James
Published in
Philologus

Dimitrov, Vasil Lemmens, Tom Mayerson, Daniel R. Min, Vincent S. Vercnocke, Bert

Gravitational wave observations of the near-horizon region of black holes lend insight into the quantum nature of gravity. In particular, gravitational wave echoes have been identified as a potential signature of quantum gravity-inspired structure near the horizon. In this paper, we connect such observables to the language of black hole microstates...

Anson, Timothy Babichev, Eugeny Charmousis, Christos Hassaine, Mokhtar

Starting from a recently constructed stealth Kerr solution of higher order scalar tensor theory involving scalar hair, we analytically construct disformal versions of the Kerr spacetime with a constant degree of disformality and a regular scalar field. While the disformed metric has only a ring singularity and asymptotically is quite similar to Ker...

Jacquet, Maxime J. Koenig, Friedrich

Quantum fluctuations on curved spacetimes cause the emission of pairs of particles from the quantum vacuum, as in the Hawking effect from black holes. We use an optical analogue to gravity to investigate the influence of the curvature on quantum emission. Due to dispersion, the spacetime curvature varies with frequency here. We analytically calcula...