PENENTUAN KONSTANTA HUBBLE MENGGUNAKAN METODE STATISTIK STANDARD SIREN DARI DATA LIGO/VIRGO

• Main Author: Ali Syaifudin, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50215
• Institution: Institut Teknologi Bandung

Hubble constant determination has a vital role in understanding the history of the universe. Nowadays, cosmological measurement has entered a new era of high precision cosmology. Dierent methods to measure cosmological parameters should converge to a single value. However, there is a signicant disagreement between the distance ladder method and the global method such as CMB in measuring Hubble constant. This problem is known as Hubble Tension. The gravitational-wave standard siren is a dierent way to measure Hubble constant independently from both methods previously mentioned. Direct detection of gravitational waves can be achieved by using laser interferometers, in the form of time-series signal of arm-length variations (strain h) which are caused by the passing through of gravitational waves. There are two laser interferometer detectors working in the USA, namely LIGOs, and one in Italy named Virgo, together are called LIGO/Virgo. The three-dimensional sky map of source probability (density) location (an output of LIGO/Virgo data analysis) is used as distance terms for Hubble constant determination. On the other hand, redshift terms are obtained from a galaxy catalog that includes location and redshift of galaxies, this Final Project uses the GLADE galaxy catalog. Both terms are combined in the Bayesian statistics framework to determine the probability density of Hubble constant, which is the goal of this Final Project, that hopefully could solve Hubble Tension. There are some constraints from three-dimensional sky maps of gravitational wave events, that are not so precise in distance and direction determination. Besides, GLADE galaxy catalog is approximately complete only up to 0:02 in redshift. Therefore only some gravitational wave events are analyzed in this Final Project. There are 28 events in total. The nal result is the Hubble constant of H0 = 71:43+35:76 ????13:12 km s????1Mpc????1 for events with luminosity distance less than 500 Mpc. This result is consistent within errors with both previously mentioned methods, not in favor of one of them.