1. School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, USA
2. School of Physics and Astronomy, Cardiff University, Cardiff, United Kingdom
3. Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
4. Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
5. Department of Astronomy and Astrophysics, University of Toronto, Toronto, Ontario M5S 3H4, Canada
6. Department of Physics and CERCA, Case Western Reserve University, Cleveland, Ohio 44106, USA
7. Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
8. Jet Propulsion Laboratory, Pasadena, California 91109, USA
9. Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, Ontario M5S 3H8, Canada
10. School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban, South Africa
11. Theoretical Physics, Blackett Laboratory, Imperial College, London, United Kingdom
12. Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
13. Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
14. Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
15. National Institute of Standards and Technology, Boulder, Colorado 80305, USA
16. Department of Physics, Stanford University, Stanford, California 94305, USA
17. Kavli Institute for Cosmology, University of Cambridge, Cambridge, United Kingdom
18. Canadian Institute for Advanced Research, CIFAR Program in Cosmology and Gravity, Toronto, Ontario M5S 3H8, Canada
19. Institut d’Astrophysique Spatiale, Orsay, France