Effective cosmological constant induced by stochastic fluctuations of Newton's constant

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• 作者：Marco de Cesare^a ; ^{marco.de_cesare@kcl.ac.uk" class="auth_mail" title="E-mail the corresponding author} ; Fedele Lizzi^b ; ^c ; ^d ; ^{fedele.lizzi@na.infn.it" class="auth_mail" title="E-mail the corresponding author} ; Mairi Sakellariadou^a ; ^{mairi.sakellariadou@kcl.ac.uk" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Quantum gravity ; Cosmology ; Cosmological constant ; Dynamical gravitational constant ; Fundamental constants
• 刊名：Physics Letters B
• 出版年：2016
• 出版时间：10 September 2016
• 年：2016
• 卷：760
• 期：Complete
• 页码：498-501
• 全文大小：249 K

文摘

We consider implications of the microscopic dynamics of spacetime for the evolution of cosmological models. We argue that quantum geometry effects may lead to stochastic fluctuations of the gravitational constant, which is thus considered as a macroscopic effective dynamical quantity. Consistency with Riemannian geometry entails the presence of a time-dependent dark energy term in the modified field equations, which can be expressed in terms of the dynamical gravitational constant. We suggest that the late-time accelerated expansion of the Universe may be ascribed to quantum fluctuations in the geometry of spacetime rather than the vacuum energy from the matter sector.