Nature 359, 393 - 396 (01 October 1992); doi:10.1038/359393a0

Large-scale structure in a universe with mixed hot and cold dark matter

Marc Davis, F. J. Summers & David Schlegel

Department of Astronomy, University of California at Berkeley, Berkeley, California 94720, USA

A UNIVERSE whose density is dominated by cold dark matter (CDM) has been considered the standard model for large-scale structure formation¹, but it has had difficulty in matching the relatively quiet velocity field of galaxies² and the observed structure on very large scales³. By contrast, models with a mixture of COM and hot dark matter (HDM) have more power on large scales^4–9, and seem more able to fit the excess large-scale power seen in galaxy surveys³ and the microwave background fluctuations recently measured by COBE^10,11. Using high-resolution numerical simulations, we examine the formation of structure in a mixed dark matter model containing 70% COM and 30% HDM, the latter in the form of massive neutrinos. This model behaves like a CDM model in which the biasing factor (the relative magnitude of structure in the dark and visible components) varies from 2.5 on small scales to <1 on large scales, and can provide a consistent explanation of both the shape of the observed fluctuation spectrum and the difference in estimates of the cosmic density, , on small and large scales.

References

1.	Davis, M., Efstathiou, G., Frenk, C. & White, S. Nature 356, 489−491 (1992). | Article |
2.	Davis, M., Efstathiou, G. P. E., Frenk, C. S. & White, S. D. M. Astrophys. J. 292, 371−394 (1985). | Article | ISI | ChemPort |
3.	Maddox, S. J., Efstathiou, G. P. E., Sutherland, W. & Loveday, J. Mon. Not. R. astr. Soc. 242, 43p−47p (1990).
4.	Holtzman, J. A. Astrophys. J. Suppl. Ser. 71, 1−24 (1989). | Article | ChemPort |
5.	Shafi, Q. & Stecker, F. W. Phys. Rev. Lett. 53, 1292−1295 (1984). | Article | ChemPort |
6.	Valdarnini, R. & Bonometto, S. A. Astr. Astrophys. 146, 235−241 (1985). | ChemPort |
7.	Achilli, S., Occhionero, F. & Scaramella, R. Astrophys. J. 299, 577−582 (1985). | Article |
8.	van Dalen, T. & Schaefer, R. K. Astrophys. J. (in the press).
9.	Schaefer, R. K. & Shafi, Q. Nature 359, 199 (1992). | Article | PubMed |
10.	Smoot, G. F. et al. Astrophys. J. 396, L1−L6 (1992). | Article | ISI |
11.	Wright, E. L. et al. Astrophys. J. 396, L13−L18 (1992). | Article |
12.	Gelb, J. thesis, Massachusetts Inst. Technol. (1991).
13.	White, S. D. M., Davis, M., Efstathiou, G. P. E. & Frenk, C. S. Nature 330, 451−453 (1987). | Article |
14.	Bardeen, J. M., Bond, J. R., Kaiser, N. & Szalay, A. S. Astrophys. J. 304, 15−61 (1986). | Article | ISI | ChemPort |
15.	Frenk, C. S. Phys. Script. T36, 70−87 (1991). | ChemPort |
16.	Babul, A. & White, S. D. M. Mon. Not. R. astr. Soc. 253, 31p−34p (1991). | ChemPort |
17.	Bower, R. G., Coles, P., Frenk, C. S. & White, S. D. M. Mon Not. R. astr. Soc. (in the press).
18.	Alimi, J. M., Vals Gabaud, D. & Blanchard, A. Astr. Astrophys. 206, L11−L14 (1988).
19.	Couchman, H. M. P. & Carlberg, R. G. Astrophys. J. 389, 453−463 (1992). | Article |
20.	Faber, S. M. & Gallagher, J. S. A. Rev. Astr. Astrophys. 17, 135−187 (1979). | Article | ISI |
21.	Davis, M. & Peebles, P. J. E. Astrophys. J. 267, 465−482; (1983). | Article | ISI |
22.	Strauss, M. A. & Davis, M. in Large-Scale Motions in the Universe, Proc. Vatican Study Week 1987, 255−274 (Princeton Univ. Press, Princeton, 1988).
23.	Kaiser, N. et al. Mon. Not. R. astr. Soc. 252, 1−12 (1992).
24.	Dekel, A. in Observational Tests of Cosmological Inflation (eds Shanks, T. et al.) 365−373 (NATO/ASI, 1990).
25.	Efstathiou, G. P. E., Sutherland, W. & Maddox, S. J. Nature 348, 705−707 (1990). | Article |
26.	Bond, J. R., Efstathiou, G. P. E. & Silk, J. Phys. Rev. Lett. 45, 1980−1983 (1980). | Article | ISI | ChemPort |
27.	Bond, J. R. & Szalay, A. S. Astrophys. J. 274, 443−468 (1983). | Article | ISI | ChemPort |
28.	Scherrer, R. J. & Bertschinger, E. Astrophys. J. 381, 349−360 (1991). | Article |
29.	Efstathiou, G., Frenk, C., White, S. & Davis, M. Astrophys. J. Suppl. Ser. 57, 241−260 (1985). | Article |
30.	Frenk, C. S., White, S. D. M., Davis, M. & Efstathiou, G. P. E. Astrophys. J. 327, 507−525 (1988). | Article | ChemPort |
31.	Ostriker, J. & Suto, Y. Astrophys. J. 348, 378−382 (1990). | Article |
32.	Taylor, A. N. & Rowan-Robinson, M. Nature 359, 396−399 (1992). | Article |
33.	Bahcall, J. N. & Bethe, H. A. Phys. Rev. Lett. 65, 2233−2235 (1990). | Article | PubMed | ChemPort |
34.	Bludman, S. A., Kennedy, D. C. & Langacker, P. G. Phys. Rev. D45, 1810−1813 (1992). | ChemPort |