Moreover, unlike the scalaron, vacuumon is treated as a classical background field, and not a fully fledged quantum field, hence cosmological perturbations will be different between the two pictures of inflation. The two representations, however, are not physically equivalent since the mechanisms of inflation are entirely different. Einstein’s general theory of relativity shows that gravity is the result of a mass, such as a planet or star, warping the geometry of the merger of time and space known as space-time. The, so-called, `running vacuum models (RVMs) are characterized by the vacuum energy density, $rho_ level, whilst in the late universe it provides an effective scalar field description of DE. (1994) 205 p 81 x and y must be suciently close in order to make sure that there exists a unique geodesic connecting them, which in turn guarantees that (x, y) is well-dened. As a consequence, one is bound to extreme fine. Wald, Quantum eld theory in curved space-time and black hole thermodynamics, Chicago, USA: Univ. They follow the time evolution of the CMB anisotropies. A plethora of phenomenological works have shown that this option can be highly competitive with the $Lambda$CDM with a rigid cosmological term. The renormalization of the vacuum energy in quantum field theory (QFT) is usually plagued with theoretical conundrums related not only with the renormalization procedure itself, but also with the fact that the final result leads usually to very large (finite) contributions incompatible with the measured value of \\Lambda in cosmology. These notes present the computation of the system of Boltzmann equations describing the evolution of the photon, baryon and cold dark matter fluids up to second order in perturbation theory. Here we stick to the $Lambda$-term, but we contend that it can be a `running quantity in quantum field theory (QFT) in curved spacetime. simple explanation in the full theory:the loop integrand is a total derivative of a function vanishing in both the deep UV and IR. Even though the model is not free of fundamental problems, they have not been circumvented by any alternative dark energy proposal either. The $Lambda$-term in Einsteins equations is a fundamental building block of the `concordance $Lambda$CDM model of cosmology.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |