PT Journal
AU Arrechea, J
   Delhom, A
   Jimenez-Cano, A
TI Inconsistencies in four-dimensional Einstein-Gauss-Bonnet gravity
SO Chinese Physics C
JI Chin. Phys. C
PY 2021
BP 013107
EP 8pp
VL 45
IS 1
DI 10.1088/1674-1137/abc1d4
LA English
DE alternative theories of gravity; singularities; Einstein-Gauss-Bonnet
AB We attempt to clarify several aspects concerning the recently presented four-dimensional Einstein-Gauss-Bonnet gravity. We argue that the limiting procedure outlined in [Phys. Rev. Lett. 124, 081301 (2020)] generally involves ill-defined terms in the four dimensional field equations. Potential ways to circumvent this issue are discussed, alongside remarks regarding specific solutions of the theory. We prove that, although linear perturbations are well behaved around maximally symmetric backgrounds, the equations for second-order perturbations are ill-defined even around a Minkowskian background. Additionally, we perform a detailed analysis of the spherically symmetric solutions and find that the central curvature singularity can be reached within a finite proper time.
ER