Strongly lensed type Ia supernovae as a precise late-universe probe of measuring the Hubble constant and cosmic curvature

TL;DR

This paper demonstrates that strongly lensed Type Ia supernovae can serve as precise late-universe probes for measuring the Hubble constant and cosmic curvature, especially with upcoming LSST data, outperforming some current methods.

Contribution

It introduces a simulation-based analysis of lensed SNe Ia as cosmological probes, showing their potential to provide competitive constraints on $H_0$ and $\

Findings

20 lensed SNe Ia can surpass SH0ES $H_0$ measurement.

100 lensed SNe Ia achieve constraints comparable to Planck 2018.

200 lensed SNe Ia can measure $H_0$ with 0.33 km/s/Mpc precision.

Abstract

Strongly lensed type Ia supernovae (SNe Ia) are expected to have some advantages in measuring time delays of multiple images, and so they have a great potential to be developed into a powerful late-universe cosmological probe. In this paper, we simulate a sample of lensed SNe Ia with time-delay measurements in the era of the Legacy Survey of Space and Time (LSST). Based on the distance sum rule, we use lensed SNe Ia to implement model-independent constraints on the Hubble constant $H_0$ and cosmic curvature parameter $\Omega_K$ in the late universe. We find that if 20 lensed SNe Ia could be observed, the constraint on $H_{0}$ is better than the measurement by the SH0ES collaboration. When the event number of lensed SNe Ia increases to 100, the constraint precision of $H_{0}$ is comparable with the result from Planck 2018 data. Considering 200 lensed SNe Ia events as the optimistic estimation, we obtain $\Delta H_0=0.33$ $\rm km\ s^{-1}\ Mpc^{-1}$ and $\Delta\Omega_K=0.053$. In addition, we also simulate lensed quasars in different scenarios to make a comparison and we find that they are still a useful cosmological probe even though the constraint precision from them is much less than that obtained from lensed SNe Ia. In the era of LSST, the measurements of time delay from both lensed SNe Ia and lensed quasars are expected to yield the results of $\Delta H_0=0.26 ~\rm km\ s^{-1}\ Mpc^{-1}$ and $\Delta\Omega_K=0.044$.