Conveners
Parallel Session Wednesday Cosmo: Cosmology I
- Gilly Elor
Parallel Session Wednesday Cosmo: Cosmology II
- Veronica Guidetti (T (Cosmology))
We study a first order phase transition in the Early Universe and the corresponding production of gravitational waves in a lattice improved holographic model for QCD, in which deconfinement is described as a Hawking-Page phase trsnsition in the holographic picture.
Extended Higgs models such as the 2HDM and the N2HDM can induce topological defects after spontaneous symmetry breaking. In this talk, I will discuss the formation of domain walls arising after the breaking of the discrete symmetries present in the aforementioned models. I will, in particular, discuss the property of localized CP violation inside the domain walls due to a difference in phase...
We study the effects of a fixed de Sitter geometry background in scenarios of false vacuum decay. It is currently understood that bubble nucleation processes associated with first order phase transitions are particularly important in cosmology. Considering the geometry of spacetime complicates the interpretation of the decay rate of a metastable vacuum. However, the effects of curvature can...
In electroweak baryogenesis, the asymmetry between matter and antimatter is generated during the electroweak phase transition. Predicting the amount of matter requires a derivation of transport equations for the CP-violating particles. For a long time, two different formalisms were
used in the literature: the semi-classical method and the vev-insertion
approximation. The latter typically...
Extension of the Two Higgs Doublet model augmented with a complex scalar singlet (2HDMS) is a well motivated candidate for Beyond Standard Model (BSM) Physics. In this talk, we focus on the dark matter (DM) phenomenology of 2HDMS and investigate cases where the singlet develops a vacuum expectation value (vev) and thereby leading to pseudoscalar DM candidate. We perform a parameter scan to...
We discuss leptogenesis in a specific scotogenic model, where the Standard Model is extended by scalar and fermionic singlets and doublets charged odd under a $Z_2$ parity. This model is phenomenologically attractive as it is designed to dynamically generate small neutrino masses, provide viable dark matter candidates and also account for the current value of the $(g_{\mu}-2)$ anomaly. In this...
A vital step toward understanding DM's nature relies on probing (or constraining) DM self-interaction, and how it interacts with the Standard Model (SM) of particle physics or with other dark sectors. An appealing DM model is to consider the presence of an interacting dark sector, i.e. considering that dark matter is gauged under a symmetry group akin to the SM. In the case those gauge fields...
A massive particle decaying into neutrinos in the early Universe is known to be less constrained than if it was decaying into other standard model particles. However, even if the decay proceeds into neutrinos, the latter still inevitably emit secondary particles undergoing electromagnetic interactions that can be probed. We analyse in details how sensitive various cosmological probes are to...
The SKA allows to map the distribution of neutral hydrogen in the Universe over a vast redshift range. The three-dimensional 21cm power spectrum found through this map can be used to perform precision tests not only for several astrophysical phenomena but also for early Universe cosmology. Even considering only a small redshift range it allows to significantly improve current constraints on...
Starobinsky (or $R^2$)-inflation is one of the current best-fit models to the Planck measurements. Extending this effective theory of gravity with the additional third order term to $f(R)=M_P^2\left(R+\frac{1}{2M^2}R^2+\frac{c}{3M^4}R^3\right)$ introduces the dimensionless parameter $c$. Using the Planck measurements, we obtain constraints on the parameters of the fundamental Lagrangian and...
Dark relics may have been produced from the decay of the primordial inflaton condensate. In this talk I discuss the possibility of producing scalar dark matter during inflation and (p)reheating. I will discuss the production regimes assuming that this scalar couples to the inflaton via a direct quartic coupling and gravity: purely gravitational, weak direct coupling (perturbative), and strong...
A kinetic coupling between photon and dark photon, a massless $U(1)$ gauge boson in the dark sector, transfers the birefringence of dark photon to the observed cosmic birefringence. Regardless of the origin of the dark birefringence, the amplitude and unique frequency-dependence of the cosmic birefringence depends on the kinetic coupling constant and the temperature of dark photon. To explain...
Hawking evaporation of primordial black holes (PBHs) can facilitate the gen-
eration of matter-antimatter asymmetry. We focus on ultra-low mass PBHs that briefly dominate the universe and evaporate before the big bang nucleosynthesis. We propose a novel test of this scenario by detecting its characteristic doubly peaked gravitational wave (GW) spectrum in future GW observatories. Here the...
