Black holes, gravitational waves and fundamental physics:A roadmap

Barack, L. and Cardoso, V. and Nissanke, S. and Sotiriou, T.P. and Askar, A. and Belczynski, C. and Bertone, G. and Bon, E. and Blas, D. and Brito, R. and Bulik, T. and Burrage, C. and Byrnes, C.T. and Caprini, C. and Chernyakova, M. and Chruściel, P. and Colpi, M. and Ferrari, V. and Gaggero, D. and Gair, J. and García-Bellido, J. and Hassan, S.F. and Heisenberg, L. and Hendry, M. and Heng, I.S. and Herdeiro, C. and Hinderer, T. and Horesh, A. and Kavanagh, B.J. and Kocsis, B. and Kramer, M. and Le Tiec, A. and Mingarelli, C. and Nardini, G. and Nelemans, G. and Palenzuela, C. and Pani, P. and Perego, A. and Porter, E.K. and Rossi, E.M. and Schmidt, P. and Sesana, A. and Sperhake, U. and Stamerra, A. and Stein, L.C. and Tamanini, N. and Tauris, T.M. and Urena-López, L.A. and Vincent, F. and Volonteri, M. and Wardell, B. and Wex, N. and Yagi, K. and Abdelsalhin, T. and Aloy, M.Á. and Amaro-Seoane, P. and Annulli, L. and Arca-Sedda, M. and Bah, I. and Barausse, E. and Barakovic, E. and Benkel, R. and Bennett, C.L. and Bernard, L. and Bernuzzi, S. and Berry, C.P.L. and Berti, E. and Bezares, M. and Blanco-Pillado, J.J. and Blázquez-Salcedo, J.L. and Bonetti, M. and Bošković, M. and Bosnjak, Z. and Bricman, K. and Brügmann, B. and Capelo, P.R. and Carloni, S. and Cerdá-Durán, P. and Charmousis, C. and Chaty, S. and Clerici, A. and Coates, A. and Colleoni, M. and Collodel, L.G. and Compère, G. and Cook, W. and Cordero-Carrión, I. and Correia, M. and De La Cruz-Dombriz, Á. and Czinner, V.G. and Destounis, K. and Dialektopoulos, K. and Doneva, D. and Dotti, M. and Drew, A. and Eckner, C. and Edholm, J. and Emparan, R. and Erdem, R. and Ferreira, M. and Ferreira, P.G. and Finch, A. and Font, J.A. and Franchini, N. and Fransen, K. and Gal'tsov, D. and Ganguly, A. and Gerosa, D. and Glampedakis, K. and Gomboc, A. and Goobar, A. and Gualtieri, L. and Guendelman, E. and Haardt, F. and Harmark, T. and Hejda, F. and Hertog, T. and Hopper, S. and Husa, S. and Ihanec, N. and Ikeda, T. and Jaodand, A. and Jetzer, P. and Jimenez-Forteza, X. and Kamionkowski, M. and Kaplan, D.E. and Kazantzidis, S. and Kimura, M. and Kobayashi, S. and Kokkotas, K. and Krolik, J. and Kunz, J. and Lämmerzahl, C. and Lasky, P. and Lemos, J.P.S. and Levi Said, J. and Liberati, S. and Lopes, J. and Luna, R. and Ma, Y.-Z. and Maggio, E. and Mangiagli, A. and Montero, M.M. and Maselli, A. and Mayer, L. and Mazumdar, A. and Messenger, C. and Ménard, B. and Minamitsuji, M. and Moore, C.J. and Mota, D. and Nampalliwar, S. and Nerozzi, A. and Nichols, D. and Nissimov, E. and Obergaulinger, M. and Obers, N.A. and Oliveri, R. and Pappas, G. and Pasic, V. and Peiris, H. and Petrushevska, T. and Pollney, D. and Pratten, G. and Rakic, N. and Racz, I. and Radia, M. and Ramazanoǧlu, F.M. and Ramos-Buades, A. and Raposo, G. and Rogatko, M. and Rosca-Mead, R. and Rosinska, D. and Rosswog, S. and Ruiz-Morales, E. and Sakellariadou, M. and Sanchis-Gual, N. and Sharan Salafia, O. and Samajdar, A. and Sintes, A. and Smole, M. and Sopuerta, C. and Souza-Lima, R. and Stalevski, M. and Stergioulas, N. and Stevens, C. and Tamfal, T. and Torres-Forné, A. and Tsygankov, S. and İ Ünlütürk, Ki. and Valiante, R. and Van De Meent, M. and Velhinho, J. and Verbin, Y. and Vercnocke, B. and Vernieri, D. and Vicente, R. and Vitagliano, V. and Weltman, A. and Whiting, B. and Williamson, A. and Witek, H. and Wojnar, A. and Yakut, K. and Yan, H. and Yazadjiev, S. and Zaharijas, G. and Zilhão, M. (2019) Black holes, gravitational waves and fundamental physics:A roadmap. Classical and Quantum Gravity, 36 (14). ISSN 0264-9381

Abstract

The grand challenges of contemporary fundamental physics—dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem—all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'.