Theory Seminar (High Energy/Cosmology) |
Events During the Week of February 20th through February 27th, 2022
Monday, February 21st, 2022
- No events scheduled
Tuesday, February 22nd, 2022
- No events scheduled
Wednesday, February 23rd, 2022
- No events scheduled
Thursday, February 24th, 2022
- No events scheduled
Friday, February 25th, 2022
- Underdamped Axionic Blue Isocurvature Perturbations
- Time: 1:00 pm
- Place: Chamberlin 5280
- Speaker: Sai Chaitanya Tadepalli, UW Madison
- Abstract: Previous computations of strongly blue tilted axionic isocurvature spectra were computed in the parametric region in which the lightest time-dependent mass is smaller than the Hubble expansion rate during inflation, leading to an overdamped time evolution. In this talk, we present the strongly blue tilted axionic isocurvature spectrum in an underdamped time evolution parametric regime. Somewhat surprisingly, there exist parametric regions with a strong resonant spectral behavior that leads to rich isocurvature spectral shapes and large amplitude enhancements. We focus on computing this resonant spectrum analytically in parametric regions amenable to such computations. Because the spectrum is sensitive to nonperturbative classical field dynamics, we will discuss a wide variety of analytic techniques that are used like decoupling, nonlinear field redefinition, a time-space effective potential obtained by integrating out high-frequency fluctuations, and a piecewise mass-model.