DINAMIKA DAN KENDALA PARAMETER MODEL DARK ENERGY DINAMIK DENGAN MEDAN SKALAR POTENSIAL -ATTRACTOR

• Main Author: Taqiaturrahmah, Aulia
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69257
• Institution: Institut Teknologi Bandung

Observations of type Ia supernovae have shown that the universe expansion is accelerating. Since generic matters can not induce acceleration, dark energy as additional component with negative pressure has been proposed. Cosmological constant is the simplest dark energy model, however it suer from energy scale and coincidence problems. Aiming at alleviating cosmological constant problems, various models of dynamical dark energy in the form of scalar elds have been put forward, such as quintessence, k-essence, and phantom eld. A model is considered more successful if accommodate a broader range of initial value (basin of attraction) and evolves convergent to the late time conditions. Unfortunately, the proposed scalar still have relatively narrow basin of attractions. Therefore, a -attractor has been proposed, and is predicted to have a vast basin of attraction with its attractor property. The dynamical behavior of -attractor is governed by its potential parameters. The parameter is responsible for the scaling, while the two power parameters, p and n, dictate the shape of the potential model. Additionally, the initial value of the led determine the evolutionary track and how it meets observational constraints for a given set of parameters. Another feature of this model is c parameter determined by the closure relation to fulll the budget energy density of the universe. Stability test was performed using autonomous method, that describes behaviours around critical points. Physically interpreted, the -attractor evolves following the equation of cosmic dynamics, that goes through generic matter and dark energy dominated eras. The results for Starobinsky potential, i.e. -attractor potential model with ???? 1, p ???? 2, and n????1, shows that there exists a stable cosmic acceleration solution. Statistical analysis employing Markov Chain Monte Carlo using supernova Ia, BAO, and CMB data was performed. CMB data is expected to give tightest constraint. But, due to not long enough running time and insucient iteration number, the parameters are still not well constrained.