Conveners
Cosmology and Gravitational Waves
- Ivonne Zavala
Cosmology and Gravitational Waves
- Ivonne Zavala
In $\mu$-hybrid inflation a nonzero inflaton vacuum expectation value induced by supersymmetry breaking is proportional to the gravitino mass $m_{3/2}$, which can be exploited to resolve the minimal supersymmetric standard model $\mu$ problem. We show how this scenario can be successfully implemented with $m_{3/2} \sim 1-100$ TeV and reheat temperature as low as $10^6$ GeV by employing a...
Given the ongoing debate by Vafa et al on inflation and the swampland, I will discuss a multifield D-brane model of inflation consistent with observational bounds. We study the model, which was previously been done as a single field, by focusing on the multifield cosmological evolution of a probe D5 brane moving in both radial and angular directions in the Warped Resolved Conifold (WRC) throat...
There is no guarantee that the reductionist point of view championed by simple effective field theories is realized during inflation and the subsequent (p)reheating. In fact, many supersymmetric and string-inspired UV completions of inflation involve a myriad of fields with complicated interactions. This may lead to a random, chaotic evolution as a function of the initial conditions and values...
"Warm inflation is an interesting alternative implementation of a period of accelerated expansion and reheating in the early universe. It turns out to be easy to have a concurrent quasi-thermal radiation bath if energy is extracted from the rolling scalar field via friction. The benefits of warm inflation include automatic reheating at the end of inflation when the thermal bath begins to...
An axion-like particle (ALP) offers a new direction in electroweak baryogenesis because the periodic nature enables it to trigger a strong first-order phase transition even if it is weakly coupled to the Higgs sector. This is essentially because the axion periodicity naturally allows the structure of phase transition to be insensitive to the axion decay constant that determines the strength of...
The Higgs boson was postulated as a key component of the Standard Model (SM) of particle physics to explain the origin of mass. After 45 years of rigorous experimental searches, the Higgs boson was finally discovered on July 4th, 2012 at the CERN Large Hadron Collider (LHC). The discovery of the Higgs boson completes the SM and confirm one of its most mysterious predictions. The SM, although...
Despite the vast literature on first order Electroweak Phase Transitions (EWPT), which can provide the necessary conditions for generating the Baryon Asymmetry in the Universe, fermion-induced EWPTs still remain a rather uncharted territory. In this talk, we consider a simple fermionic extension of the Standard Model (SM) involving one $ SU(2)_L$ doublet and two singlet Vector-Like Leptons...
I will discuss how late universe dark matter decays to a massive and a massless daughter particles can relieve the tension between measurements of the Hubble parameter in the local universe and at the CMB.
We have developed a cosmological model by allowing the speed of light c, gravitational constant G and cosmological constant Λ in the Einstein filed equation to vary in time, and solved them for Robertson-Walker metric. Assuming the universe is flat and matter dominant at present, we obtain a simple model that can fit the supernovae 1a data with a single parameter almost as well as the standard...