Luminosity-Duration Relation of Fast Radio Bursts: a new tool for precision cosmology
Tetsuya Hashimoto1*, Goto, Tomotsugu1, Wang, Ting-Wen1, Kim, Seong Jin1, Wu, Yi-Han2, Ho, Chien-Chang1
1Physics/IoA, National Tsing Hua University, Hsinchu, Taiwan
2Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, California, USA
* Presenter:Tetsuya Hashimoto,
Nature of dark energy remains unknown. Especially, to constrain the time variability of the dark-energy, a new, standardisable candle that can reach more distant Universe has been awaited. Here we propose a new distance measure using fast radio bursts (FRBs), which are a new emerging population of ~ms time scale radio bursts that can reach high-z in quantity. We, for the first time, show an empirical positive correlation between the time-integrated luminosity (L_nu) and rest-frame intrinsic duration (w_int,rest) of FRBs. The L_nu-w_int,rest correlation is statistically very significant with >95% confidence level. This correlation can be used to measure intrinsic luminosity of FRBs from the observed w_int,rest. By comparing the luminosity with observed flux, we measure luminosity distances to FRBs, and thereby construct the Hubble diagram. This FRB cosmology with the L_nu-w_int,rest relation has several advantages over SNe Ia, Gamma-Ray Burst (GRB), and well-known FRB dispersion measure (DM)-z cosmology; (i) access to higher redshift Universe beyond the SNe Ia, (ii) high event rate that is ~3 order of magnitude more frequent than GRBs, and (iii) it is free from the uncertainty from intergalactic electron density models, i.e., we can remove the largest uncertainty in the well-debated DM-z cosmology of FRB. Our simulation suggests that the L_nu-w_int,rest relation provides tight constraints on the time variability of the dark energy when the next generation radio telescopes start to find FRBs in quantity.

Keywords: Cosmology, Fast radio burst, Dark energy