Cosmology Intertwined I: Perspectives for the next decade
Abstract
The standard Λ Cold Dark Matter cosmological model provides an amazing description of a wide range of astrophysical and astronomical data. However, there are a few big open questions, that make the standard model look like a firstorder approximation to a more realistic scenario that still needs to be fully understood. In this Letter of Interest we will list a few important goals that need to be addressed in the next decade, also taking into account the current discordances present between the different cosmological probes, as the Hubble constant H_{0} value, the σ_{8}S_{8} tension, and the anomalies present in the Planck results. Finally, we will give an overview of upgraded experiments and nextgeneration spacemissions and facilities on Earth that will be of crucial importance to address all these questions.
What is the nature of dark energy and dark matter?
Did the universe have an inflationary period? How did it happen? What is the level of nongaussianities?
Does gravity behave like General Relativity even at horizon size scales? Is there Modified Gravity?
Do we need quantum gravity, or an unified theory for quantum field theory and General Relativity?
Is the universe flat, open or closed?
What is the age of the universe?
Do we actually need physics beyond the Standard Model (SM) of particle physics?
For each elementary particle, there is an antiparticle that has exactly the very same properties but opposite charge. Then, why we do not see antimatter in the universe?
Will the swampland conjectures of string theory help with finetuning problems in cosmology? Alternatively, will cosmology help us observationally test conjectures from string theory?
 Publication:

Astroparticle Physics
 Pub Date:
 September 2021
 DOI:
 10.1016/j.astropartphys.2021.102606
 arXiv:
 arXiv:2008.11283
 Bibcode:
 2021APh...13102606D
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics;
 High Energy Physics  Phenomenology
 EPrint:
 Snowmass2021  Letter of Interest