The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
Eleonora Di Valentino, Jackson Levi Said, Adam G. Riess, Agnieszka Pollo, Vivian Poulin, Adrià Gómez-Valent, Amanda Weltman, A. Palmese, Caroline D. Huang, Carsten van de Bruck, Chandra Shekhar Saraf, Cheng‐Yu Kuo, Cora Uhlemann, Daniela Grandón, Dante J. Paz, D. Eckert, Elsa M. Teixeira, Emmanuel N. Saridakis, Eoin Ó Colgáin, Florian Beutler, Florian Niedermann, Francesco Bajardi, Gabriela Barenboim, Giulia Gubitosi, I. Musella, Indranil Banik, István Szapudi, J. Singal, Jaume de Haro, Jens Chluba, Jesús Torrado, Jurgen Mifsud, Karsten Jedamzik, Khaled Said, Konstantinos F. Dialektopoulos, Laura Herold, Leandros Perivolaropoulos, Lei Zu, L. Galbany, Louise Breuval, Luca Visinelli, Luis A. Escamilla, Luis A. Anchordoqui, M. M. Sheikh-Jabbari, M Lembo, Maria Giovanna Dainotti, M. Vincenzi, Marika Asgari, M. Gerbino, Matteo Forconi, Michele Cantiello, M. Moresco, Micol Benetti, Nils Schöneberg, Özgür Akarsu, Rafael C. Nunes, Reginald Christian Bernardo, Ricardo Chávez, Richard I. Anderson, Richard Watkins, Salvatore Capozzıello, Siyang Li, Sunny Vagnozzi, Supriya Pan, Tommaso Treu, Vid Iršič, Will Handley, William Giarè, Yukei S. Murakami, Abdolali Banihashemi, Adèle Poudou, Alan Heavens, A. Kogut, Alba Domi, Aleksander Łukasz Lenart, A. Melchiorri, Alessandro Vadalà, A. Amon, Alexander Bonilla Rivera, Alexander G. Reeves, Alexander Zhuk, A. Bonanno, Ali Övgün, Alice Pisani, Alireza Talebian, Amare Abebe, Amin Aboubrahim, Ana Luisa González Morán, András Kovács, Andreas Lymperis, Andreas Papatriantafyllou, Andrew R. Liddle, Andronikos Paliathanasis, A. Borowiec, Anil K. Yadav, Anita Yadav, Anjan A. Sen, Anjitha John William, Anne-Christine Davis, Anowar J. Shajib
Abstract
The standard model of cosmology has provided a good phenomenological description of a wide range of observations both at astrophysical and cosmological scales for several decades. This concordance model is constructed by a universal cosmological constant and supported by a matter sector described by the standard model of particle physics and a cold dark matter contribution, as well as very early-time inflationary physics, and underpinned by gravitation through general relativity. There have always been open questions about the soundness of the foundations of the standard model. However, recent years have shown that there may also be questions from the observational sector with the emergence of differences between certain cosmological probes. In this White Paper, we identify the key objectives that need to be addressed over the coming decade together with the core science projects that aim to meet these challenges. These discordances primarily rest on the divergence in the measurement of core cosmological parameters with varying levels of statistical confidence. These possible statistical tensions may be partially accounted for by systematics in various measurements or cosmological probes but there is also a growing indication of potential new physics beyond the standard model. After reviewing the principal probes used in the measurement of cosmological parameters, as well as potential systematics, we discuss the most promising array of potential new physics that may be observable in upcoming surveys. We also discuss the growing set of novel data analysis approaches that go beyond traditional methods to test physical models. These new methods will become increasingly important in the coming years as the volume of survey data continues to increase, and as the degeneracy between predictions of different physical models grows. There are several perspectives on the divergences between the values of cosmological parameters, such as the model-independent probes in the late Universe and model-dependent measurements in the early Universe, which we cover at length. The White Paper closes with a number of recommendations for the community to focus on for the upcoming decade of observational cosmology, statistical data analysis, and fundamental physics developments. Download: Download high-res image (270KB) Download: Download full-size image