21 citations · 32 across the 8 of their papers we have counts for
9 papers · 1 filter
The Lanczos potential in the Plebanski paradigm of gravity
Daniel Espín, Alejandro Jiménez Cano, Javier Olmedo +1
We present a new Plebanski formulation of General Relativity. The key difference is that we work with a gauge vector field derived from the Lanczos potential of the Weyl tensor. We…
Physical nonviability of in the scalar-tensor representation
Jose Beltrán Jiménez, Alejandro Jiménez Cano, Tomi S. Koivisto
We show the known pathological character of gravity in its scalar-tensor representation.
Cosmological Spacetimes with Sign-Changing Spatial Curvature and Topological Transitions
Gerardo García-Moreno, Bert Janssen, Alejandro Jiménez Cano +3
Observational evidence, together with practical computations and modeling, supports a Euclidean spatial sector in the current cosmological model based on the FLRW metric. This, how…
Toroidal black holes in four dimensions
Carlos Barceló, Gerardo García-Moreno, Alejandro Jiménez Cano
From a purely geometric (kinematic) perspective, black holes in four dimensional spacetimes can have event horizons with arbitrary topologies. It is only when energy conditions are…
Foliation-generating observers under Lorentz transformations
Daniel Blixt, Alejandro Jiménez Cano, Aneta Wojnar
In this work, we revise the concept of foliation and related aspects that are crucial when formulating the Hamiltonian evolution for various theories beyond General Relativity. In…
A class of ghost-free theories in symmetric teleparallel geometry
Antonio G. Bello-Morales, Jose Beltrán Jiménez, Alejandro Jiménez Cano +2
Theories formulated in the arena of teleparallel geometries are generically plagued by ghost-like instabilities or other pathologies that are ultimately caused by the breaking of s…
Pathological Character of Modifications to Coincident General Relativity: Cosmological Strong Coupling and Ghosts in $f(\Q)$ Theories
Débora Aguiar Gomes, Jose Beltrán Jiménez, Alejandro Jiménez Cano +1
The intrinsic presence of ghosts in the symmetric teleparallel framework is elucidated. We illustrate our general arguments in theories by studying perturbations in…
Nonexistence of a parent theory for general relativity and unimodular gravity
Gerardo García-Moreno, Alejandro Jiménez Cano
General Relativity (GR) and Unimodular Gravity (UG) provide two equivalent descriptions of gravity that differ in the nature of the cosmological constant. While GR is based on the…
On the physical viability of black hole solutions in Einsteinian Cubic Gravity and its generalisations
Jose Beltrán Jiménez, Alejandro Jiménez-Cano
In this note, we discuss the pathological nature of black holes in Einsteinian Cubic gravity and its extensions. We compute the equations for the odd perturbations and show how sph…