AAS 197, January 2001
Session 72. Cosmology from z=1100 to 1
Display, Wednesday, January 10, 2001, 9:30am-7:00pm, Exhibit Hall

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[72.04] Halo Formation in Warm Dark Matter Models

P. Bode, J. P. Ostriker (Princeton University), N. Turok (DAMTP)

We have examined the warm dark matter (WDM) model using high resolution N-body simulations, and identified a number of distinctive observational signatures. We find that replacing cold with warm dark matter has the following effects:

1. Smoothing of massive halo cores, lowering core densities and increasing core radii.

2. Lowering greatly the characteristic density of low mass halos.

3. Reduction of the overall number of low mass halos.

4. Suppression of the number of low mass satellite halos in high mass halos.

5. Formation of low mass halos almost solely within caustic pancakes or ribbons connecting larger halos in a `cosmic web'. Voids in this web are almost empty of small halos, in contrast to the situation in CDM theory.

6. Late formation (z<4) of low mass halos, in a `top down' process. 7. Suppression of halo formation at high redshift (z>5), and increased evolution of halos at lower redshifts relative to CDM.

The first four findings indicate that WDM holds some promise as a solution to the satellite and core density problems of CDM. The fifth may solve a problem raised by Peebles ( Principles of Physical Cosmology, p. 26). The sixth and seventh items point to observational tests at high redshift.

This research was supported by the NCSA Grand Challenge Computation Cosmology Partnership (under NSF Cooperative Agreement ACI-9619019, PACI Subaward 766) and a PPARC (UK) rolling grant.

If you would like more information about this abstract, please follow the link to http://astro.Princeton.EDU/~bode/. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

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