标题： 非最小导数耦合宇宙学与引力波的速度 显示英文标题

标题： Nonminimal Derivative Coupling Cosmology and the Speed of Gravitational Waves

摘要： 所谓的非最小导数耦合（NDC）是广义相对论的一种替代理论，在宇宙学中的应用会产生一种渐近的膨胀机制。 过去十年引力波的探测对引力理论施加了非常严格的限制，这促使人们对这些理论进行了大规模修订，以调查它们与观测数据之间的兼容性。 本文回顾了NDC，并探讨了它是否与引力波相容的问题。 我们表明，该理论中引力波的存在局限于相空间的一个有限范围内，且不存在与目前关于此类波速度的数据相一致的加速解。 最后这一结果由于我们尚未探测到原初引力波而有所缓解。 这些结论是基于张量扰动速度表达式与相空间的比较得出的。 最后，考虑了一些可能的情景和解决方案。 显示英文摘要

摘要： The so-called Nonminimal Derivative Coupling (NDC) is an alternative to General Relativity, which produces an asymptotic inflationary mechanism when applied to cosmology. The detection of gravitational waves in the last decade has imposed very stringent constraints over gravitational theories, which gave rise to a massive revision of those theories, in order to investigate the compatibility between them and that observational data. In this paper, we review NDC and address the question if it is compatible with gravitational waves or not. We show that the very existence of gravitational waves in this theory is restricted to a limited range in phase space and there are no accelerated solutions compatible with the present day data for the speed of such waves. This last result is alleviated by the fact that we did not detect primordial gravitational waves so far. Those conclusions are based on the comparison between the expression for the speed of tensor perturbations and the phase space. Finally, some possible scenarios and solutions are considered.