%0 Generic %1 gilman2021primordial %A Gilman, Daniel %A Benson, Andrew %A Bovy, Jo %A Birrer, Simon %A Treu, Tommaso %A Nierenberg, Anna %D 2021 %K tifr %T The primordial matter power spectrum on sub-galactic scales %U http://arxiv.org/abs/2112.03293 %X The primordial matter power spectrum quantifies fluctuations in the distribution of dark matter immediately following inflation. Over cosmic time, over-dense regions of the primordial density field grow and collapse into dark matter halos, whose abundance and density profiles retain memory of the initial conditions. By analyzing the image magnifications in eleven strongly-lensed and quadruply-imaged quasars, we infer the abundance and concentrations of low-mass halos, and cast the measurement in terms of the amplitude of the primordial matter power spectrum $Płeft(k\right)$ on (inverse) length scales $1 < k < 50 \ Mpc^-1$. Assuming an analytic model for the power spectrum and accounting for several sources of potential systematic uncertainty, including three different models for the halo mass function, we infer $łog_10łeft(P / P_Łambda CDM\right)$, the power spectrum amplitude relative to the predictions of the concordance cosmological model, of $0.0_-0.4^+0.4$, $0.1_-0.7^+0.6$, and $0.2_-1.0^+0.9$ at k = 10, 25 and 50 $Mpc^-1$ at $68 \%$ confidence. Our inference makes contact with the properties of the early Universe on smaller scales than existing measurements have accessed, and agrees with the predictions of cold dark matter and single-field slow-roll inflation.

@misc{gilman2021primordial, abstract = {The primordial matter power spectrum quantifies fluctuations in the distribution of dark matter immediately following inflation. Over cosmic time, over-dense regions of the primordial density field grow and collapse into dark matter halos, whose abundance and density profiles retain memory of the initial conditions. By analyzing the image magnifications in eleven strongly-lensed and quadruply-imaged quasars, we infer the abundance and concentrations of low-mass halos, and cast the measurement in terms of the amplitude of the primordial matter power spectrum $P\left(k\right)$ on (inverse) length scales $1 < k < 50 \ \rm{Mpc^{-1}}$. Assuming an analytic model for the power spectrum and accounting for several sources of potential systematic uncertainty, including three different models for the halo mass function, we infer $\log_{10}\left(P / P_{\Lambda \rm{CDM}}\right)$, the power spectrum amplitude relative to the predictions of the concordance cosmological model, of $0.0_{-0.4}^{+0.4}$, $0.1_{-0.7}^{+0.6}$, and $0.2_{-1.0}^{+0.9}$ at k = 10, 25 and 50 $\rm{Mpc^{-1}}$ at $68 \%$ confidence. Our inference makes contact with the properties of the early Universe on smaller scales than existing measurements have accessed, and agrees with the predictions of cold dark matter and single-field slow-roll inflation.}, added-at = {2021-12-08T08:28:07.000+0100}, author = {Gilman, Daniel and Benson, Andrew and Bovy, Jo and Birrer, Simon and Treu, Tommaso and Nierenberg, Anna}, biburl = {https://www.bibsonomy.org/bibtex/249b2e008572243dcf2a5f47afafd0d81/citekhatri}, description = {The primordial matter power spectrum on sub-galactic scales}, interhash = {5dac378602cd7e9e67842f10d3d9e6e1}, intrahash = {49b2e008572243dcf2a5f47afafd0d81}, keywords = {tifr}, note = {cite arxiv:2112.03293Comment: 19 pages, 10 figures}, timestamp = {2021-12-08T08:28:07.000+0100}, title = {The primordial matter power spectrum on sub-galactic scales}, url = {http://arxiv.org/abs/2112.03293}, year = 2021 }