Beyond ΛCDM : Problems, solutions, and the road ahead

Summary, in English

Despite its continued observational successes, there is a persistent (and growing) interest in extending cosmology beyond the standard model, ΛCDM. This is motivated by a range of apparently serious theoretical issues, involving such questions as the cosmological constant problem, the particle nature of dark matter, the validity of general relativity on large scales, the existence of anomalies in the CMB and on small scales, and the predictivity and testability of the inflationary paradigm. In this paper, we summarize the current status of ΛCDM as a physical theory, and review investigations into possible alternatives along a number of different lines, with a particular focus on highlighting the most promising directions. While the fundamental problems are proving reluctant to yield, the study of alternative cosmologies has led to considerable progress, with much more to come if hopes about forthcoming high-precision observations and new theoretical ideas are fulfilled.

• Author: Philip Bull; Yashar Akrami; Julian Adamek; Tessa Baker; Emilio Bellini; Jose Beltrán Jiménez; Eloisa Bentivegna; Stefano Camera; Sébastien Clesse; Jonathan H. Davis; Enea Di Dio; Jonas Enander; Alan Heavens; Lavinia Heisenberg; Bin Hu; Claudio Llinares; Roy Maartens; Edvard Mörtsell; Seshadri Nadathur; Johannes Noller; Roman Pasechnik; Marcel S. Pawlowski; Thiago S. Pereira; Miguel Quartin; Angelo Ricciardone; Signe Riemer-Sørensen; Massimiliano Rinaldi; Jeremy Sakstein; Ippocratis D. Saltas; Vincenzo Salzano; Ignacy Sawicki; Adam R. Solomon; Douglas Spolyar; Glenn D. Starkman; Danièle Steer; Ismael Tereno; Licia Verde; Francisco Villaescusa-Navarro; Mikael von Strauss; Hans A. Winther
• Department/s: Theoretical Particle Physics - Has been reorganised
• Publishing year: 2016-06-01
• Language: English
• Pages: 56-99
• Publication/Series: Physics of the Dark Universe
• Volume: 12
• Links: http://dx.doi.org/10.1016/j.dark.2016.02.001
• Document type: Journal article
• Publisher: Elsevier
• Topic: Astronomy, Astrophysics and Cosmology
• Keywords: Cosmological constant problem; Cosmology; Dark energy; Dark matter; Early universe; Modified gravity
• Status: Published
• ISBN/ISSN/Other: ISSN: 2212-6864