Ryo Tsutsui

Cosmological Constraints from calibrated Yonetoku and Amati relation implies Fundamental plane of Gamma-ray bursts (2008)

Tsutsui, Ryo, Nakamura, Takashi, Yonetoku, Daisuke, Murakami, Toshio, Kodama, Yoshiki, Takahashi, Keitaro

We consider two empirical relations using data only from the prompt emission of Gamma-Ray Bursts (GRBs), peak energy ($E_p$) - peak luminosity ($L_p$) relation (so called Yonetoku relation) and...

Constraints on $w_0$ and $w_a$ of Dark Energy from High Redshift Gamma Ray Bursts (2008)

Tsutsui, Ryo, Nakamura, Takashi, Yonetoku, Daisuke, Murakami, Toshio, Tanabe, Sachiko, Kodama, Yoshiki, ...

We extend the Hubble diagram up to $z = 5.6$ using 63 gamma-ray bursts (GRBs) via peak energy-peak luminosity relation (so called Yonetoku relation), and obtain constraints on cosmological parameters...

Gamma-Ray Bursts in $1.8 < z < 5.6$ Suggest that the Time Variation of the Dark Energy is Small (2008)

Kodama, Yoshiki, Yonetoku, Daisuke, Murakami, Toshio, Tanabe, Sachiko, Tsutsui, Ryo, Nakamura, Takashi

We calibrated the peak energy-peak luminosity relation of GRBs (so called Yonetoku relation) using 33 events with the redshift $z < 1.62$ without assuming any cosmological models. The luminosity...

Redshift Dependent Lag-Luminosity Relation in 565 BASTE Gamma Ray Bursts (2007)

Tsutsui, Ryo, Nakamura, Takashi, Yonetoku, Daisuke, Murakami, Toshio, Tanabe, Sachiko, Kodama, Yoshiki

We compared redshifts $z_Y$ from Yonetoku relation and $z_{lag}$ from the lag-luminosity relation for 565 BASTE GRBs and were surprised to find that the correlation is very low. Assuming that the...