PHYS08200605006 D.K. Hazra - Homi Bhabha National Institute
PHYS08200605006 D.K. Hazra - Homi Bhabha National Institute
PHYS08200605006 D.K. Hazra - Homi Bhabha National Institute
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CHAPTER 6. EFFECTS OF PRIMORDIAL FEATURES ON THE FORMATION OF HALOS<br />
100000<br />
1000<br />
Quadratic potential<br />
Quadratic potential with a step<br />
Quadratic potential with sinusoidal modulation<br />
Axion monodromy model<br />
P M<br />
(k)h −3 Mpc 3<br />
1<br />
10000<br />
1000<br />
0.01 0.1<br />
0.001<br />
0.0001 0.01 1 100<br />
khMpc −1<br />
Figure 6.4: The best fit matter power spectrum P M<br />
(k) corresponding to the different inflationary<br />
scalar power spectra we had plotted in the earlier figure. The inset highlights the<br />
imprints of the primordial features on the matter power spectrum in the domain where<br />
the baryon acoustic oscillations also play a role. The black dots with bars corresponds<br />
to the power spectrum data from SDSS obtained upon combining main galaxies and the<br />
LRGs with error bars arrived at from the diagonal elements of the corresponding covariance<br />
matrix. It should be noted that, since we have plotted the linear power spectrum,<br />
without taking into account the non-linear effects, the theoretical best fit curves are unable<br />
to fit the data for k > 0.1hMpc −1 .<br />
potential.<br />
In order to arrive at the maximum possible change in the number density of halos<br />
when compared to the conventional nearly scale invariant primordial spectrum, for the<br />
models with oscillations in the potential, we have chosen values for the parametersαand<br />
β that lie within2-σ from the best fit values. We have chosen the parameters in such a way<br />
that they create the largest deviation from the nearly scale invariant power spectra that<br />
are allowed by the CMB and the LSS data. In Figure 6.5, apart from the results for the best<br />
fit values, we have plotted the number density and the formation rates of halos for the<br />
cases wherein[α,ln(β/M Pl<br />
)] is set to(2×10 −3 ,−1.7) and(2×10 −4 ,−3.5) for the quadratic<br />
potential with the sinusoidal modulations and the axion monodromy model, respectively.<br />
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