Inconsistencies in four-dimensional Einstein-Gauss-Bonnet gravity

• 来源期刊: 中国物理C（英文版）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: PARTICLES AND FIELDS
• 页码范围: 89-96
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-1137/abc1d4

摘要

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)]gener-ally 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.