Running Vacuum and the ΛCDM tensions

In the last few years a lot of work has provided significant support to the possibility that the vacuum energy density (VED), ρvac, is a running quantity throughout the cosmological history. Recent theoretical studies have shown that the properly renormalized ρvac in FLRW spacetime adopts the `runni...

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Detalles Bibliográficos
Autor: Solà Peracaula, Joan
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/212780
Acceso en línea:https://hdl.handle.net/2445/212780
Access Level:acceso abierto
Palabra clave:Cosmologia quàntica
Espai i temps
Buit
Quantum cosmology
Space and time
Vacuum
Descripción
Sumario:In the last few years a lot of work has provided significant support to the possibility that the vacuum energy density (VED), ρvac, is a running quantity throughout the cosmological history. Recent theoretical studies have shown that the properly renormalized ρvac in FLRW spacetime adopts the `running vacuum model' (RVM) form, in which the scaling with the renormalization point turns into dependence on the Hubble rate, H. The late time VED evolves as an additive term plus a dynamical component O(H2). Higher (even) powers O(H2n) are also predicted, which can trigger inflation in the early universe, although we shall not discuss this part here. In addition, the VED running is free from the quartic powers of the masses of the fields (∼m4) and hence the cosmic evolution of ρvac is really smooth. On the phenomenological side, the RVM fits the cosmological data remarkably well and it may help to reduce the H0 and σ8 tensions afflicting the ΛCDM. Overall, the RVM is sound since its theoretical structure can be derived from quantum field theory in curved spacetime and the model is phenomenologically consistent.