Phenomenology 2022 Symposium: From Virtual to Real

Session

Cosmology IV

10 May 2022, 16:30

Lawrence Hall 106

Conveners

Cosmology IV

• Vedran Brdar

211. Gravitational Waves from an Inflation Triggered First-Order Phase Transition

Kunfeng Lyu (University of Minnesota)

10/05/2022, 16:30

Large excursion of the inflaton field can trigger interesting dynamics. One important example is a first-order phase transition in a spectator sector which couples to the inflaton. Gravitational waves (GWs) from such a first-order phase transition during inflation, an example of an instantaneous source, have an oscillatory feature. In this work, we show that this feature is generic for a...

196. Cosmological Measurements of Light but Massive Relics

Nicholas DePorzio

10/05/2022, 16:45

Cosmological data provide a powerful tool in the search for physics beyond the Standard Model (SM). An interesting target are light relics, new degrees of freedom which decoupled from the Standard Model while relativistic. Nearly massless relics contribute to the radiation energy budget, and are commonly searched through variations in the effective number Neff of neutrino species....

195. Constraints on Self-interacting Radiations with Cosmological Data

Jae Hyeok Chang (JHU/UMD)

10/05/2022, 17:00

Self-interacting radiations are generic consequences of many BSM models. I present a comprehensive study of cosmological constraints on self-interacting light relics using cosmic microwave background and baryon acoustic oscillation data. In this talk, I will describe how to implement self-interacting radiation in the Boltzmann hierarchy and show results for different types of relics and interactions.

193. High-pT muons in cosmic-ray air showers

Shirley Li (Fermilab)

10/05/2022, 17:15

The composition of high-energy cosmic rays is a long-standing puzzle in astrophysics. One obstacle to understanding the composition is the significant theoretical uncertainties in predicting high-energy cosmic-ray air showers, which is difficult to improve because most air shower observables are sensitive to the details of the collinear region. To combat this problem, IceCube has measured...

165. Correlating Gravitational Wave and Gamma-ray Signals from Primordial Black Holes

Steven Clark (Brown University)

10/05/2022, 17:30

Primordial black holes are produced in the early Universe by large curvature perturbations and can explain the dark matter abundance within current constraints. During their creation, gravitational waves are produced that could be measured by future gravitational wave detectors. These black holes will also produce a visible electromagnetic signature through Hawking radiation that may similarly...

101. A Step in Understanding the Hubble Tension

Melissa Joseph

10/05/2022, 17:45

As cosmological data have improved, tensions have arisen. One such tension is the difference between the locally measured Hubble constant $H_0$ and the value inferred from the cosmic microwave background (CMB). Interacting radiation has been suggested as a solution, but studies show that conventional models are precluded by high-ℓ CMB polarization data. It seems at least plausible that a...

2. Neff constraint on portal interaction with hidden sectors

Pranjal Ralegankar

10/05/2022, 18:00

Measurement of the effective number of neutrino species, $N_{\rm eff}$, by future cosmic microwave background (CMB) experiments is expected to be sensitive enough to rule out new relativistic particles that were in equilibrium with the Standard model (SM) plasma, if the measured $N_{\rm eff}$ value is consistent with the SM value of 3.044. Consequently, the interaction between the new...