Cosmological Parameters from the BOSS Galaxy Power Spectrum. (arXiv:1909.05277v1 [astro-ph.CO])

<a href="http://arxiv.org/find/astro-ph/1/au:+Ivanov_M/0/1/0/all/0/1">Mikhail M. Ivanov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Simonovic_M/0/1/0/all/0/1">Marko Simonović</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zaldarriaga_M/0/1/0/all/0/1">Matias Zaldarriaga</a>

We present cosmological parameter measurements from the publicly available

Baryon Oscillation Spectroscopic Survey (BOSS) data on anisotropic galaxy

clustering in Fourier space. Compared to previous studies, our analysis has two

main novel features. First, we use a complete perturbation theory model that

properly takes into account the non-linear effects of dark matter clustering,

short-scale physics, galaxy bias, redshift-space distortions, and large-scale

bulk flows. Second, we employ a Markov-Chain Monte-Carlo technique and

consistently reevaluate the full power spectrum likelihood as we scan over

different cosmologies. Assuming a minimal $Lambda$CDM cosmology with massive

neutrinos, fixing the primordial power spectrum tilt, and imposing the big bang

nucleosynthesis (BBN) prior on the physical baryon density $omega_b$, we find

the following late-Universe parameters: Hubble constant $H_0=(67.89pm 1.06)$

km$,$s$^{-1}$Mpc$^{-1}$, matter density fraction $Omega_m=0.295pm 0.010$,

and the mass fluctuation amplitude $sigma_8=0.721pm 0.043$. These parameters

were measured directly from the BOSS data and independently of the Planck

cosmic microwave background observations. Our constraints remain unchanged if

we replace the BBN prior on $omega_b$ by a tighter Planck constraint. Finally,

we discuss the information content of the BOSS power spectrum and show that it

is dominated by the location of the baryon acoustic oscillations and the power

spectrum shape. We argue that the contribution of the Alcock-Paczynski effect

is marginal in $Lambda$CDM, but becomes important for non-minimal cosmological

models.

We present cosmological parameter measurements from the publicly available

Baryon Oscillation Spectroscopic Survey (BOSS) data on anisotropic galaxy

clustering in Fourier space. Compared to previous studies, our analysis has two

main novel features. First, we use a complete perturbation theory model that

properly takes into account the non-linear effects of dark matter clustering,

short-scale physics, galaxy bias, redshift-space distortions, and large-scale

bulk flows. Second, we employ a Markov-Chain Monte-Carlo technique and

consistently reevaluate the full power spectrum likelihood as we scan over

different cosmologies. Assuming a minimal $Lambda$CDM cosmology with massive

neutrinos, fixing the primordial power spectrum tilt, and imposing the big bang

nucleosynthesis (BBN) prior on the physical baryon density $omega_b$, we find

the following late-Universe parameters: Hubble constant $H_0=(67.89pm 1.06)$

km$,$s$^{-1}$Mpc$^{-1}$, matter density fraction $Omega_m=0.295pm 0.010$,

and the mass fluctuation amplitude $sigma_8=0.721pm 0.043$. These parameters

were measured directly from the BOSS data and independently of the Planck

cosmic microwave background observations. Our constraints remain unchanged if

we replace the BBN prior on $omega_b$ by a tighter Planck constraint. Finally,

we discuss the information content of the BOSS power spectrum and show that it

is dominated by the location of the baryon acoustic oscillations and the power

spectrum shape. We argue that the contribution of the Alcock-Paczynski effect

is marginal in $Lambda$CDM, but becomes important for non-minimal cosmological

models.

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