Open Access

Niayesh Afshordi, Sarp Akçay, Pau Amaro-Seoane, Andrea Antonelli, Josu C. Aurrekoetxea, Leor Barack, Enrico Barausse, Robert Benkel, Laura Bernard, Sebastiano Bernuzzi, Emanuele Berti, Matteo Bonetti, Béatrice Bonga, Gabriele Bozzola, Richard Brito, Alessandra Buonanno, Alejandro Cárdenas-Avendaño, Marc Casals, David F. Chernoff, Alvin J. K. Chua, Katy Clough, Marta Colleoni, Mekhi Dhesi, Adrien Druart, Leanne Durkan, Guillaume Faye, Deborah Ferguson, Scott E. Field, William E. Gabella, Juan García-Bellido, Miguel Gracia-Linares, Davide Gerosa, Stephen R. Green, Maria Haney, Mark Hannam, Anna Heffernan, Tanja Hinderer, Thomas Helfer, Scott A. Hughes, Sascha Husa, Soichiro Isoyama, Michael L. Katz, Chris Kavanagh, Gaurav Khanna, Larry E. Kidder, Valeriya Korol, Lorenzo Küchler, Pablo Laguna, François Larrouturou, Alexandre Le Tiec, Benjamin Leather, Eugene A. Lim, Hyun Lim, Tyson B. Littenberg, Oliver Long, Carlos O. Lousto, Geoffrey Lovelace, Georgios Lukes-Gerakopoulos, Philip Lynch, Rodrigo P. Macedo, Charalampos Markakis, Elisa Maggio, Ilya Mandel, Andrea Maselli, Josh Mathews, Pierre Mourier, David Neilsen, Alessandro Nagar, David A. Nichols, Jan Novák, Maria Okounkova, Richard O’Shaughnessy, Naritaka Oshita, Conor O’Toole, Zhen Pan, Paolo Pani, George Pappas, Vasileios Paschalidis, Harald P. Pfeiffer, Lorenzo Pompili, Adam Pound, Geraint Pratten, Hannes Rüter, Milton Ruiz, Zeyd Sam, Laura Sberna, Stuart L. Shapiro, Deirdre M. Shoemaker, Carlos F. Sopuerta, Andrew Spiers, Hari Sundar, Nicola Tamanini, Jonathan E. Thompson, Alexandre Toubiana, Antonios Tsokaros, Samuel D. Upton, Maarten van de Meent, Daniele Vernieri, Jeremy M. Wachter, Niels Warburton, Barry Wardell, Helvi Witek, Vojtěch Witzany, Huan Yang, Miguel Zilhão, Angelica Albertini, K. G. Arun, Miguel Bezares, Alexander Rivera Bonilla, Christian Chapman-Bird, Bradley Cownden, Kevin Cunningham, Chris Devitt, Sam Dolan, Francisco Duque, Conor Dyson, Chris L. Fryer, Jonathan R. Gair, Bruno Giacomazzo, Priti Gupta, Wen-Biao Han, Roland Haas, Eric Hirschmann, Eliu A. Huerta, Philippe Jetzer, Bernard Kelly, Mohammed Khalil, Jack Lewis, Nicole Marie Lloyd-Ronning, Sylvain Marsat, Germano Nardini, Jakob Neef, Adrian Ottewill, Christiana Pantelidou, Gabriel Andres Piovano, Jaime Redondo-Yuste, Laura Sagunski, Leo C. Stein, Viktor Skoupý, Ulrich Sperhake, Lorenzo Speri, Thomas F. M. Spieksma, Chris Stevens, David Trestini, Alex Vañó-Viñuales

• LISA, the Laser Interferometer Space Antenna, will usher in a new era in gravitational-wave astronomy. As the first anticipated space-based gravitational-wave detector, it will expand our view to the millihertz gravitational-wave sky, where a spectacular variety of interesting new sources abound: from millions of ultra-compact binaries in our Galaxy, to mergers of massive black holes at cosmological distances; from the beginnings of inspirals that will venture into the ground-based detectors' view to the death spiral of compact objects into massive black holes, and many sources in between. Central to realising LISA's discovery potential are waveform models, the theoretical and phenomenological predictions of the pattern of gravitational waves that these sources emit. This white paper is presented on behalf of the Waveform Working Group for the LISA Consortium. It provides a review of the current state of waveform models for LISA sources, and describes the significant challenges that must yet be overcome.