【24h】

Hyperbolicity constraints in extended gravity theories

机译:扩展重力理论的双曲性约束

获取原文
获取原文并翻译 | 示例
           

摘要

We study the characteristic structure of the Einstein-Hilbert (EH) action when modifications of the form of R-2, R-mu upsilon(2), R-mu upsilon rho sigma(2) and C-mu upsilon rho sigma(2) are included. We show that when these quadratic terms are significant, the initial value problem is generically ill-posed. We do so by demanding the hyperbolicity of the effective metric for propagation of perturbations. Here, we find a general expression for the effective metric in field space and calculate it explicitly about the cosmological Friedman-Robertson-Walker spacetime, and the spherically symmetric Schwarzschild solution. We find that when these quadratic contributions are non-negligible, the signature of the effective metric becomes non-Lorentzian and hence non-hyperbolic. As a consequence, we conclude that theories suggesting the inclusion of these terms can only be considered as a perturbative extension of the EH action and therefore cannot constitute a true alternative to general relativity.
机译:我们研究了爱因斯坦-Hilbert(EH)行动的特征结构,当修饰R-2,R-Mu Upsilon(2),R-Mu Upsilon Rho Sigma(2)和C-Mu Upsilon Rho Sigma(2 ) 被包含在内。我们表明,当这些二次术语显着时,初始值问题在普遍存在的情况下。我们通过要求扰动繁殖的有效度量的双曲性来这样做。在这里,我们发现了现场空间中有效度量的一般表达,并明确计算宇宙学弗里德曼 - 罗伯逊 - 沃克时刻,以及球体对称的Schwarzschild解决方案。我们发现,当这些二次贡献是不可忽略的时,有效度量的签名变为非Lorentzian,因此是非双曲线的。因此,我们得出结论,提出纳入这些术语的理论只能被视为欧盟行动的扰动延长,因此不能构成一般相对性的真正替代方案。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号