http://arxiv.org/abs/1807.04980
Thermal inflation models (which feature two inflationary stages) can display damped primordial curvature power spectra on small scales which generate damped matter fluctuations. For a reasonable choice of parameters, thermal inflation models naturally predict a suppression of the matter power spectrum on galactic and sub-galactic scales, mimicking the effect of warm or interacting dark matter. Matter power spectra in these models are also characterised by an excess of power (with respect to the standard $\Lambda$CDM power spectrum) just below the suppression scale. By running a suite of N-body simulations we investigate the non-linear growth of structure in models of thermal inflation. We measure the non-linear matter power spectrum and extract halo statistics, such as the halo mass function, and compare these quantities with those predicted in the standard $\Lambda$CDM model and in other models with damped matter fluctuations. We find that the thermal inflation models considered produce measurable differences in the matter power spectrum from $\Lambda$CDM at redshifts $z>5$, while the halo mass functions are appreciably different even at $z=0$. We also study the accuracy of the Press-Schechter analytical approach, with different filters, in predicting halo statistics for thermal inflation. We find that the predictions with the smooth-$k$ filter we proposed in a separate paper agree with the simulation results over a wider range of halo masses than is the case with other filters commonly used in the literature.
M. Leo, C. Baugh, B. Li, et. al.
Mon, 16 Jul 18
27/55
Comments: 25 pages, 15 figures. LaTeX. Prepared for submission to JCAP