# Can Kilonova Light curves be Standardized?

## TL;DR

This study explores whether kilonova light curves from neutron star mergers can be standardized for distance measurement, using theoretical models to identify potential correlations similar to those in supernovae.

## Contribution

The paper demonstrates, through theoretical modeling, that kilonova light curves exhibit significant correlations, suggesting they could be standardized in future observations.

## Key findings

- Theoretical models show strong correlations in kilonova light curves.
- Potential for standardizing kilonovae for cosmological distance measurements.
- Future observations could confirm these correlations in real data.

## Abstract

Binary neutron star mergers have been recently confirmed to be the progenitors of the optical transients kilonovae (KNe). KNe are powered by the radioactive decay of neutron-rich elements (r-process elements) which are believed to be the product of disruption of neutron stars during their merger. KNe exhibit interesting parallels with type Ia supernovae (SNe), whose light curves show specific correlations which allow them to be used as standardizable candles. In this paper, we investigate the possibility of the KN light curves exhibiting similar correlations. While a satisfactory answer to this question can only be provided by future KN observations, employing theoretical models we explore whether there is any ground for harboring such expectations. Using semi-analytic models of KN light curves in conjunction with results from numerical relativity simulations of binary neutron star mergers, we obtain the maximum bolometric luminosity ($L_{\mathrm{Bol}}^{\mathrm{max}}$) and decline in luminosity ($\Delta L_{\mathrm{Bol}}$) for a simulated population of mergers. We find that theoretical light curves of KNe show remarkable correlations despite the complex physics governing their behavior. This presents a possibility of future observations to uncover such correlations in the observed light curves, eventually allowing observers to standardize these light curves and to use them for local distance measurements.