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Tuesday, 13 November 2007, 14:30 in SSB7172
Dr. Gong-Bo Zhao (SFU)
Dark energy perturbation and its application on cosmology
Dark Energy (DE) is amongst the biggest enigma in modern cosmology. The nature of dark energy dominates the fate of our universe and the perturbation of DE plays a crucial role in theoretical study as well as in the determination of cosmological parameters. The latest astronomical observations, including supernova type Ia (SN Ia), cosmic microwave background (CMB) and large scale structure (LSS), mildly favor the equation of state w of DE crossing over the cosmological boundary during evolution. However, there exists divergence in perturbation equation when w crosses over -1, which gives rise to the classical difficulty in global fit of cosmological parameters. In this talk, I will firstly study the dark energy perturbation in theory and propose a strategy to handle the perturbation in parameter fitting based on Quintom model. Then I will investigate the correlations of dynamical dark energy with inflation parameters, neutrino mass and curvature of space-time. The nature of neutrino is another challenge to modern physics. The mass of neutrino, which is beyond the standard model of particle physics, is of great significance theoretically. With the latest astronomical data, I will study the correlation between neutrino mass and inflationary parameters and the cosmological constraints of mass varying neutrinos. I will show that the neutrino mass limit can be relaxed dramatically if neutrino mass varies and mass varying neutrinos are favored at about 3 sigma for some data combination. This discovery challenges the fundamental particle physics and cosmology to a great extent.
Seminars in 2007:
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Modified by Andrei Frolov <frolov@sfu.ca> on 2023-11-01