Kyohei Mukaida
(DESY)
26/09/2019, 16:00
Cosmology & Astroparticle Physics
The coupling of an axion-like particle driving inflation to the Standard Model particle content through a Chern-Simons term generically sources a dual production of massless helical gauge fields and chiral fermions. We demonstrate that the interplay of these two components results in a highly predictive baryogenesis model, which requires no further ingredients beyond the Standard Model. If the...
Dr
Andrey Saveliev
(Immanuel Kant Baltic Federal University)
26/09/2019, 16:15
Cosmology & Astroparticle Physics
The origin of the first magnetic fields in the Universe is a standing problem in cosmology. Intergalactic Magnetic Fields (IGMFs) may be an untapped window to the primeval Universe, providing further constrains on magnetogenesis. We demonstrate the feasibility of using gamma rays from electromagnetic cascades originating from TeV blazars and Ultra-High-Energy Cosmic Rays...
Dr
Fazlollah Hajkarim
(Goethe University Frankfurt)
26/09/2019, 16:30
Cosmology & Astroparticle Physics
Using the quantum chromodynamics (QCD) equation of state (EoS) from lattice calculations we investigate effects from QCD on primordial gravitational waves (PGWs) produced during the inflationary era. We also consider different cases for vanishing and nonvanishing lepton asymmetry where the latter one is constrained by cosmic microwave background experiments.
Also, we investigate scenarios...
Dr
Mikael Chala
(UGR & IPPP)
26/09/2019, 16:45
Cosmology & Astroparticle Physics
I will discuss the dependence of the parameters describing the gravitational waves produced in a first order phase transition (Tn, alpha, beta/H) on
the global properties
(e.g. height of the barrier) of the scalar that spontaneously tunnels
between two
vacua. Particularizing on the Higgs field, I will show the potential
of gravitational wave observatories to unravel its global...
Mr
Juan S. Cruz
(TUM)
26/09/2019, 17:05
Cosmology & Astroparticle Physics
Following previous work on self-consistent methods geared towards dealing with false vacuum decay in quantum field theory; a $U(1)$-gauge theory with a complex scalar is considered together with a polynomial potential which presents a metastable vacuum at tree level. Fluctuations around an inhomogeneous bounce-type background interpolating between vacua are studied and computed within a 1-PI...
Mr
Felix Giese
(DESY/Hamburg U.)
26/09/2019, 17:20
Cosmology & Astroparticle Physics
We discuss vacuum stability in Froggatt-Nielsen (FN) models. One concern in FN models is that for large flavon VEVs the running of the quartic Higgs coupling is enhanced what might lead to a more severe instability compared to the Standard Model (SM). We study this issue using the renormalization-group improved scalar potential. Another issue is that the
mixing between the Higgs and the...
