Dr
Jinsu Kim
(Georg-August University Goettingen)
26/09/2019, 14:00
Cosmology & Astroparticle Physics
Inflationary models based on particle physics naturally involve multiple fields in addition to the inflaton field. Consequently these multiple fields may contribute to inflaton correlation functions via loop corrections. We study the quantum corrections to the inflaton two-point correlation functions due to massive scalar and fermion fields, employing the Schwinger-Keldysh formalism. We shall...
Jorinde Van de Vis
(NIKHEF Amsterdam)
26/09/2019, 14:15
Cosmology & Astroparticle Physics
We study particle production after multifield inflation with
nonminimal couplings to gravity. A comparison between a linearized
treatment and lattice simulations allows us to determine when nonlinear
effects, such as rescattering and backreaction, become important. We
track the equation of state on the lattice and show that it relaxes to
1/3. We also show that the spectra of the produced...
Yohei Ema
(DESY)
26/09/2019, 14:30
Cosmology & Astroparticle Physics
We point out that a light scalaron dynamically emerges if scalar fields have a sizable non-minimal coupling to the Ricci scalar as in the Higgs inflation model. We support this claim in two ways. One is based on the renormalization group equation; the non-minimal coupling inevitably induces a Ricci scalar quadratic term due to the renormalization group running. The other is based on scattering...
Gilles Buldgen
(UC Louvain)
26/09/2019, 14:45
Cosmology & Astroparticle Physics
“Warm Inflation” is an alternative to the standard inflationary paradigm in cosmology. It is characterized by a quasi-equilibrium between the dissipation due to particle production and the dilution due to the Hubble expansion, which keeps a thermal bath of radiation at a constant high temperature during inflation. We derive a quantum kinetic equation of motion for a slowly-rolling scalar field...
Azadeh Maleknejad
(MPA Garching)
26/09/2019, 15:00
Cosmology & Astroparticle Physics
Primordial SU(2) gauge fields coupled to axions can contribute
to the physics of inflation. Their rich phenomenology and unique
observational features, e.g., chiral primordial gravitational waves,
turned this class of models to a hot topic of study since their
discovery in 2011. In this talk, I will briefly review the models in
this class, which so far have been studied in the literature....
Mr
Stefan Sandner
(IFIC / CSIC)
26/09/2019, 15:20
Cosmology & Astroparticle Physics
I will talk about early Universe inflation driven by an axion-like particle interacting with (non-) Abelian gauge fields. In the case of a non-Abelian gauge group, this can lead to the formation of a stable, homogeneous and isotropic gauge field background. However this only happens significantly after the relevant CMB scales left the horizon. This makes the model practically indistinguishable...
