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

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 Simonovi&#x107;</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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