CosmoDEC · Cosmological Dark Energy Condensate (CosmoDEC): A unified description of the Dark Universe
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-03-01 → 2023-02-28
- EU contribution
- €191,149
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Cosmological Dark Energy Condensate (CosmoDEC): A unified description of the Dark Universe
Modern physics stands on the shoulders of giants: the General theory of Relativity and the Standard Model of particle physics. The former provides an exceptionally precise description of the gravitational force at vastly different scales, from the solar system to the whole universe. The latter, instead, describes the constituents of matter at the most fundamental level. However, despite representing the state-of-the-art of our understanding of Nature, these models have shortcomings. The emergence of singularities, such as the Big Bang or at the endpoint of the gravitational collapse to form a black hole, clearly signals that General Relativity is no longer applicable and it is necessary to go beyond this model. Furthermore, even when describing the dynamics of the universe at large scales, one is forced to include exotic forms of matter and energy (dubbed dark matter and dark energy, respectively) to reconcile theory and observations. On top of that, while the standard model is an inherently quantum theory, General Relativity is classical and its full quantum-mechanical characterization is unknown. In the corpuscular gravity theory, a new approach to quantum gravity in which the gravitational interaction heals itself by producing marginally bound states of gravitons, the classical notion of spacetime emerges as a collective effect. The objective of the Action was to build upon this idea and show that one can fit gravitational effects at all scales in a unified framework without ingredients beyond the Standard Model. This investigation has led to the formulation of a rigorous formalism describing the emergence of the geometry from a mean-field description of the gravitational interaction. When applied to cosmology, these new tools have confirmed that a modified Newtonian dynamics can emerge at galactic scales as a result of the competition between short- and large-scale (i.e., cosmological) effects in the full quantum state of the system. Furthermore, this new formalism was applied to black hole physics, leading to a natural resolution of important problems afflicting the classical picture of these objects.
Data: CORDIS, © European Union
Project objective
A staggering amount of observational evidence, ranging from the study of the distribution of matter at large scales to galactic rotation curves, suggests the existence of an exotic form of matter. This alleged new component, which accounts for around a quarter of the energy content of our universe, is usually referred to as dark matter. The existence of this dark sector was also strongly supported by the fact that the sole gravitational interaction sourced by ordinary visible matter largely fails to account for structure formation in the early universe. Furthermore, redshift measurements of Type Ia Supernovae have shown that the universe is expanding at an accelerating rate, hence supporting the need for an additional dark energy component in the present-day observable universe. Thus, our current understanding of fundamental physics, encoded in the Standard Model of Particle Physics and the theory of General Relativity (GR), seems to suggest that we can only account for roughly 5% of the matter content of the cosmos, while the rest of it remains almost uncharted territory. The corpuscular theory of gravity offers a way to describe gravity in the strong coupling regime according to which GR completes itself in the UV through the process of classicalization. This pictures allows one to conceive the current cosmic expansion as driven by a ''cosmological condensate'' of gravitons. Besides, if one adds some ''baryonic impurities'' (galaxies and clusters) to this ''cosmological condensate'', then Milgrom's Modified Newtonian Dynamics (MOND) naturally emerges, in the corpuscular framework, as the response of the condensate to the local presence of ordinary matter. The scope of the proposed research is to build on these premises by combining the general wisdom of effective field theories of gravity, focusing on its ultra-violet (UV) self-completion, and the idea that that the two dark components can interact and source one another.
Original text from CORDIS.
Participants
- EIDGENOESSISCHE TECHNISCHE HOCHSCHULE ZUERICH · ZuerichCoordinatorSwitzerland
Links
Data: CORDIS, © European Union