Model-independent distance measurements from gamma-ray bursts and constraints on dark energy

Journal Article · Mon Dec 15 04:00:00 EST 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.123532· OSTI ID:21251121

Yun, Wang ^[1]

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1. Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, Oklahoma 73019 (United States)

Gamma-ray bursts (GRB) are the most energetic events in the Universe and provide a complementary probe of dark energy by allowing the measurement of cosmic expansion history that extends to redshifts greater than 6. Unlike type Ia supernovae (SNe Ia), GRBs must be calibrated for each cosmological model considered, because of the lack of a nearby sample of GRBs for model-independent calibration. For a flat universe with a cosmological constant, we find {omega}{sub m}=0.25{sub -0.11}{sup +0.12} from 69 GRBs alone. We show that the current GRB data can be summarized by a set of model-independent distance measurements, with negligible loss of information. We constrain a dark energy equation of state linear in the cosmic scale factor using these distance measurements from GRBs, together with the ''Union'' compilation of SNe Ia, WMAP five-year observations, and the SDSS (Sloan Digital Sky Survey) baryon acoustic oscillation scale measurement. We find that a cosmological constant is consistent with current data at 68% confidence level for a flat universe. Our results provide a simple and robust method to incorporate GRB data in a joint analysis of cosmological data to constrain dark energy.

• OSTI ID: 21251121
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 12 Vol. 78; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
BARYONS
CALIBRATION
COSMIC GAMMA BURSTS
COSMOLOGICAL CONSTANT
COSMOLOGICAL MODELS
EQUATIONS OF STATE
EXPANSION
LOSSES
NONLUMINOUS MATTER
OSCILLATIONS
RED SHIFT
SUPERNOVAE
UNIVERSE