Cosmological Parameters From Supernovae Associated With Gamma-ray Bursts

We report estimates of the cosmological parameters $\Omega_m$ and $\Omega_{\Lambda}$ obtained using supernovae (SNe) associated with gamma-ray bursts (GRBs) at redshifts up to 0.606. Eight high-fidelity GRB-SNe with well-sampled light curves across the peak are used. We correct their peak magnitudes for a luminosity-decline rate relation to turn them into accurate standard candles with dispersion $\sigma = 0.18$ mag. We also estimate the peculiar velocity of the low-redshift host galaxy of SN 1998bw, using constrained cosmological simulations. In a flat universe, the resulting Hubble diagram leads to best-fit cosmological parameters of $(\Omega_m, \Omega_{\Lambda}) = (0.58^{+0.22}_{-0.25},0.42 ^{+0.25}_{-0.22})$. This exploratory study suggests that GRB-SNe can potentially be used as standardizable candles to high redshifts to measure distances in the universe and constrain cosmological parameters.