Journal Club

Seminar Room

Tuesday 7th of November, 2023

Title: Cosmic inflation and the Seesaw mechanism

Presented by: Gabriel Rodrigues

Abstract: In the past decade, cosmology and oscillation experiments have placed tight constraints on the sum of neutrino masses, $\sum M_\nu$. While the current tightest bounds come from CMB and LSS observations ($\sum M_\nu < 0.0866\;eV$), neutrino oscillation experiments provide measurements of the neutrino mass-squared splittings, namely atmospheric mass splitting ($|\Delta m_{31}^2|\approx 2.55\times 10^{-3}\;eV^2$) and solar mass splitting ($|\Delta m_{21}^2|\approx 7.5\times 10^{-5}\;eV^2$). Since the ordering of the mass of the neutrino is still unknown, there are two possible constraints from these particle physics experiments, i.e., $\sum M_\nu > 0.06\;eV$ for the normal ordering and $\sum M_\nu > 0.10\;eV$ for the inverted ordering. The Seesaw mechanism is one of the proposed models to explain the generation of these tiny neutrino masses. In its minimal realization, it includes three heavy right-handed neutrinos and a scalar field. On the other hand, a scalar field also plays an important role in inflationary dynamics of the primordial universe. In our analysis, we focus on an inflationary model called Double-Well inflation, characterized by a potential $V(\phi)=\frac{\lambda}{4}(\phi^2+v^2)^2$. To constrain the parameters of the inflationary model, we perform a Markov Chain Monte Carlo (MCMC) analysis using the latest Planck temperature and polarization data combined with measurements of the baryon acoustic oscillations and type Ia Supernovae. In this work, we aim to establish a connection between the observational constraints on the inflationary parameters and the bounds on the sum of neutrino mass.

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Title: Classical Physics and Quantum Loops

Presented by: Luis Gil Martín

Abstract: 

Ref: https://arxiv.org/pdf/hep-th/0405239.pdf