We present the first cosmological constraints from analyzing higher-order galaxy clustering on non-linear scales. We use ${ \rm S{ \scriptsize IM}BIG}$, a forward modeling framework for galaxy clustering analyses that employs simulation-based inference to perform highly efficient cosmological inference using normalizing flows. It leverages the predictive power of high-fidelity simulations and robustly extracts cosmological information from regimes inaccessible with current standard analyses. In this work, we apply ${ \rm S{ \scriptsize IM}BIG}$ to a subset of the BOSS galaxy sample and analyze the redshift-space bispectrum monopole, $B_0(k_1, k_2, k_3)$, to $k_{ \rm max}=0.5\,h/{ \rm Mpc}$. We achieve 1$\sigma$ constraints of $\Omega_m=0.293^{ +0.027}_{ -0.027}$ and $\sigma_8= 0.783^{ +0.040}_{ -0.038}$, which are more than 1.2 and 2.4$\times$ tighter than constraints from standard power spectrum analyses of the same dataset. We also derive 1.4, 1.4, 1.7$\times$ tighter constraints on $\Omega_b$, $h$, $n_s$. This improvement comes from additional cosmological information in higher-order clustering on non-linear scales and, for $\sigma_8$, is equivalent to the gain expected from a standard analysis on a $\sim$4$\times$ larger galaxy sample. Even with our BOSS subsample, which only spans 10% of the full BOSS volume, we derive competitive constraints on the growth of structure: $S_8 = 0.774^{ +0.056}_{ -0.053}$. Our constraint is consistent with results from both cosmic microwave background and weak lensing. Combined with a $\omega_b$ prior from Big Bang Nucleosynthesis, we also derive a constraint on $H_0=67.6^{ +2.2}_{ -1.8}\,{ \rm km\,s^{ -1}\,Mpc^{ -1}}$ that is consistent with early universe constraints.
Categories: astro-ph.CO