.. number of authors for an ArXiV paper:

Sub-millimetre galaxies reside in dark matter halos with masses greater than 3x10^11 solar masses


Alexandre Amblard, Asantha Cooray, Paolo Serra (UC Irvine), B. Altieri, V. Arumugam, H. Aussel, A. Blain, J. Bock, A. Boselli, V. Buat, N. Castro-Rodriguez, A. Cava, P. Chanial, E. Chapin, D.L. Clements, A. Conley, L. Conversi, C.D. Dowell, E. Dwek, S. Eales, D. Elbaz, D. Farrah, A. Franceschini, W. Gear, J. Glenn, M. Griffin, M. Halpern, E. Hatziminaoglou, E. Ibar, K. Isaak, R.J. Ivison, A.A. Khostovan, G. Lagache, L. Levenson, N. Lu, S. Madden, B. Maffei, G. Mainetti, L. Marchetti, G. Marsden, K. Mitchell-Wynne, H.T. Nguyen, B. O'Halloran, S.J. Oliver, A. Omont, M.J. Page, P. Panuzzo, A. Papageorgiou, C.P. Pearson, I. Perez-Fournon, M. Pohlen, N. Rangwala, I.G. Roseboom, M. Rowan-Robinson, M. Sanchez Portal, B. Schulz, Douglas Scott, N. Seymour, D.L. Shupe, A.J. Smith, J.A. Stevens, M. Symeonidis, M. Trichas, K. Tugwell, M. Vaccari, E. Valiante, I. Valtchanov, J. D. Vieira, L. Vigroux, L. Wang, R. Ward, G. Wright, C.K. Xu, M. Zemcov et al. (13 additional authors not shown)
They seem to assume that Dark Matter has been around since the start, which rather puts the kibosh on the idea it could be produced in any great quantities by ultra high-energy particle collisions near black holes.