Conveners
Cosmology and the early Universe: Chair
- Sarunas Verner (University of Florida)
Cosmology and the early Universe: Joint Dark Matter / Cosmology
- Maria Martinez
An accurate description of the scalar potential at finite temperature is crucial for studying cosmological first-order phase transitions (FOPT) in the early Universe. At finite temperatures, a precise treatment of thermal resummations is essential, as bosonic fields encounter significant infrared issues that can compromise standard perturbative approaches. The Partial Dressing (or the tadpole...
We explore the nature of a certain type of supercooled phase transition, mainly motivated by supersymmetric theories, where the supercooling is guaranteed to end due to the curvature sign flipping of the finite-temperature effective potential at the origin. In such models, the potential barrier trapping the scalar field at the metastable origin quickly vanishes at the temperature scale of the...
Gravitational Waves (GWs) offer a powerful window into the physics of the early Universe and could provide a novel probe of high-scale leptogenesis models. In this talk, I will explore how GW observations can shed light on a class of GUT-inspired seesaw models based on the $U(1)_{B-L}$ gauge symmetry. In these scenarios, the scalar field $\Phi$ responsible for the spontaneously breaking of...
We revisit the thermal leptogenesis based on the Type I seesaw mechanism and discuss the constraints from future neutrino experiments. We especially focus on the impact of the neutrinoless double-beta decay. Numerically solving the density matrix equation, which can describe the flavor effects, we present the lower bounds of right-handed neutrino mass required for successful leptogenesis as a...
We explore flavored resonant leptogenesis embedded in a neutrinophilic 2HDM. Successful leptogenesis is achieved by the very mildly degenerate two heavier right-handed neutrinos~(RHNs) $N_2$ and $N_3$ with a level of only $\Delta M_{32}/M_2 \sim \mathcal{O}(0.1\%-1\%)$. The lightest RHN, with a MeV–GeV mass, lies below the sphaleron freeze-out temperature and is stable, serving as a dark...
If the $B-L$ symmetry is gauged with the addition of right-handed neutrinos, the standard model $B-L$ current is anomalous with respect to the $B-L$ gauge field itself. Then, the anomaly relation implies that the magnetic helicity of the $B-L$ gauge field is related to the standard model $B-L$ charges, although the whole universe is $B-L$ neutral with right-handed neutrinos. Based on this, we...
We study primordial gravitational waves (GWs) generated from first-order phase transitions (PTs) during cosmic reheating. Using a minimal particle physics model, and a general parametrization of the inflaton energy density and the evolution of the Standard Model temperature, we explore the conditions under which PTs occur and determine the corresponding PT parameters (the PT temperature,...
In this talk, I will present a novel mechanism for gravitational wave generation from spectator scalar fields in the early universe. Spectator scalar fields with masses below the inflationary scale can produce significant isocurvature power spectra in the ultraviolet region, generating substantial curvature perturbations at small scales. These perturbations result in a stochastic gravitational...
In this talk, I will explore how gravitational-wave(GW) observations of compact binary mergers can provide insight into properties of dark matter through examples of specific models which predict the formation of compact objects detectable by current and future GW detectors. GW signals from black hole binaries that form from the cooling and gravitational collapse of dissipative dark matter...
Primordial black holes (PBHs) are compelling dark matter candidates and potential probes of new physics. Gravitational wave observations offer a unique avenue for detecting sub-solar mass black holes, objects not expected from known astrophysical processes.
In addition to PBHs, we consider other exotic compact object (ECO) candidates—such as strange quark stars and boson stars—which can...
In this talk, we look at some cosmological constraints on majoron dark matter in the singlet Majoron model. We consider two scenarios: pre-inflationary and post inflationary spontaneous lepton number symmetry breaking, while simultaneously demanding thermal leptogenesis to happen, and neutrino masses being generated by the type I seesaw mechanism. We derive the constraints and future prospects...
I will present some of our recent proposals for detecting axions and gravitational waves using unconventional methods, such as cryogenic quantum transport technology, artificial magnetoelectric materials, and spin systems. These proposals may have promising sensitivity for axions with masses ranging from kHz to GHz, and a similar device can also be used for high-frequency gravitational wave...
