Descripción del proyecto
Formación de galaxias en un multiverso con más de una constante cosmológica
En 1917, Albert Einstein introdujo la constante cosmológica con el fin de contrarrestar la atracción gravitatoria causante de la expansión acelerada del universo, ya que en aquella época no se sabía que el universo se estuviera expandiendo. Este término es la densidad de energía presente en el espacio o densidad de energía en el vacío, y la densidad de energía oscura es directamente proporcional a ella. Sin embargo, los valores esperados de la constante cosmológica son varios órdenes de magnitud superiores a los observados experimentalmente. El proyecto COSFORM, financiado por el Consejo Europeo de Investigación, revisará el pequeño valor de densidad registrado para el vacío emplazándolo en el contexto de un multiverso (es decir, en el marco de múltiples universos creados a partir de un número infinito de big bangs simultáneos) e investigará cómo se vería afectada la formación de galaxias por diferentes cantidades de energía del vacío.
Objetivo
This application proposes a programme of research directed at the outstanding puzzle of modern cosmology: the strangely small non-zero value of the vacuum density. This can be approached in three ways: (1) Evolution; (2) Revision of gravity;(3) Observer selection in the multiverse. The first two of these can be addressed by ongoing and future large galaxy surveys. Part of the research programme is directed at new ways of assuring robust measurements from these surveys of the main diagnostics of interest -- the effective equation of state of dark energy and the growth rate of density fluctuations. This will exploit and extend current work on systematics of galaxy properties as a function of large-scale environment in the cosmic web.
But so far such tests show no deviation from standard gravity and a cosmological constant. This fact drives interest in a multiverse solution, in which different causally disconnected domains may be able to possess different effective cosmological constants. This research will concentrate on the astrophysically interesting question of how galaxy formation would be affected by different levels of vacuum energy. This previously been addressed only by oversimplified analytic arguments, and it is possible that the exponential sensitivity of galaxy formation efficiency to the vacuum density could be very different to the simple estimates. Current claims that the multiverse approach predicts the right level for the cosmological constant would then be disproved. In any case, there is much of interest to be learned regarding the robustness of current theories of galaxy formation by 'stress-testing' them outside the rather restricted parameter regimes normally considered. The result will be a deeper understanding of the assembly of cosmic structure in our universe, as well as indications of how it might have proceeded in other members of an ensemble.
Ámbito científico
- natural sciencesphysical sciencestheoretical physicsparticle physics
- natural sciencesphysical sciencesquantum physics
- natural sciencesphysical sciencesastronomyastrophysicsblack holes
- natural sciencesphysical sciencesastronomyastrophysicsdark matter
- natural sciencesphysical sciencesastronomyphysical cosmologygalaxy evolution
Programa(s)
Régimen de financiación
ERC-ADG - Advanced GrantInstitución de acogida
EH8 9YL Edinburgh
Reino Unido