Dissertation Defense Schedule
Academic Excellence
Sharing original dissertation research is a principle to which the University of Delaware is deeply committed. It is the single most important assignment our graduate students undertake and upon completion is met with great pride.
We invite you to celebrate this milestone by attending their dissertation defense. Please review the upcoming dissertation defense schedule below and join us!
PROGRAM | Physics
Modern constraints on F-term SUSY hybrid inflation models
By: Matthew Civiletti Chair: Qaisar Shafi
ABSTRACT
We study modifications of supersymmetric hybrid inflation, which continues to be one of the most popular inflationary models. The seminal formulation considered the $V_{G + Delta V}$ potential, in which one can show that $Delta_mathcal{R} sim left( frac{M}{m_P} right)^2$, which indicates that the breaking scale $M sim 10^{16}$ GeV. This is a non-trivial fact, and provides a clue the group may be a Grand Unified Theory (GUT). Inspired by this, we consider inflating while constraining the breaking scale $M$ at the MSSM gauge coupling unification scale, $2.86 times 10^{16}$ GeV. We show that one can inflate successfully; in particular, we use non-minimal K”{a}hler to achieve, for the recent Planck bounds $0.945<n_s<0.975$, $r simeq 3 times 10^{-4}$ in the case where $V$ is bounded from below, and $r simeq 1 times 10^{-2}$ where this condition is relaxed. Unfortunately, GUTs tend to predict topological defects. To ameliorate this problem, we consider the addition of a Planck-suppressed term which gives rise to shifted inflation, where one inflates in a similar way except that $vert phi vert neq 0$. We show that one can inflate successfully; one achieves similar results as in the standard case, including the large $r$ solutions particular to non-minimal K"{a}hler contributions. We achieve $r simeq 0.02$, which is similar to the non-minimal standard case. Finally, we consider a generalization of the model to include Planck-suppressed R-symmetry violation, parametrized by $alpha$. One can generate masses more naturally in MSSM by treating R-symmetry as approximate, and we discover that, keeping to the standard inflationary track $vert phi vert= 0$, the effect is to raise $r$ in the preferred $n_s$ range by about four orders of magnitude as compared with the standard case, for $alpha simeq 10^{-9}$. By considering $alpha simeq 10^{-7}$, one can achieve $r simeq 10^{-4}$. This is fairly remarkable in that it is done with only minimal K"{a}hler.
The Process
Step-by-Step
Visit our “Step-by-Step Graduation Guide” to take you through the graduation process.From formatting your Dissertation to Doctoral Hooding procedures.
Dissertation Manual
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Defense Submission Form
This form must be completed two weeks in advance of a dissertation defense to meet the University of Delaware Graduate and Professional Education’s requirements.
