Physics & Astronomy ETDs

Publication Date

Summer 6-27-2018

Abstract

Neutrinos are abundantly produced in astrophysical environments such as core-collapse supernovae and binary neutron star mergers. Neutrino flavor conversions in the dense media play important roles in the physical and chemical evolutions of the environments. In this dissertation, I study two mechanisms through which neutrinos may change their flavors.

In the first mechanism, neutrinos can experience flavor conversions through interactions with oscillatory perturbations in matter distributions. I show that this mechanism can be understood intuitively as Rabi oscillations. I also derive criteria which can be used to determine whether such parametric resonances exist in a given environment.

In the second mechanism, the whole neutrino medium can experience flavor conversions because of the neutrino self-interactions. Applying the linearized flavor stability analysis method to the dense neutrino medium with discrete and continuous angular emissions, I show that, contrary to a recent conjecture by I. Izaguirre et al., the flavor instabilities are not always associated with the gaps in dispersion relation curves of the collective modes of neutrino oscillations. I also develop a toy model and a numerical scheme which can be used to explore neutrino oscillations in an environment where scattered neutrino fluxes are present.

Degree Name

Physics

Level of Degree

Doctoral

Department Name

Physics & Astronomy

First Committee Member (Chair)

Professor Huaiyu Duan

Second Committee Member

Professor Rouzbeh Allahverdi

Third Committee Member

Professor Daniel Finley

Fourth Committee Member

Professor Dinesh Loomba

Fifth Committee Member

Professor Yong-Zhong Qian

Language

English

Keywords

neutrino, supernova

Document Type

Dissertation

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