Conveners
Parallel 5
- Pyungwon Ko (KIAS)
Cosmological scalar phase transitions are ubiquitous in particle physics models. If they are first-order, they can be tested with gravitational-wave signal and baryon asymmetry they produce. These however, crucially depend on the velocity that nucleated new-phase bubbles reached. In this talk I will present generalized description which builds a bridge between numerical simulations, often used...
Strong first-order phase transitions offer a compelling explanation for the stochastic gravitational wave background in the nano-Hertz range measured by pulsar timing arrays (PTA). In this talk, I will consider a dark Higgs mechanism in a classically conformal dark sector where the symmetry breaking of a dark $U(1)^{\prime}$ gives rise to a gravitational wave background that can fit the PTA...
In models beyond the Standard Model, a first-order phase transition could be realized. Gravitational waves produced in such a phase transition may provide a window into new physics through their observable signatures. However, it is known that there are significant theoretical uncertainties in the spectrum of gravitational waves, such as those arising from RGE effects.
In this talk, we...
The current experimental data suggest that the Standard Model Higgs potential is metastable, with a second, deeper AdS minimum emerging at high scales. Assuming that the Higgs boson initially resides in this AdS minimum, this talk will explore how the presence of axionic fields or magnetic radiation can catalyze the onset of inflation through asymptotically AdS Euclidean wormholes. The initial...
In multi-field inflationary models couplings between fields are not limited to a potential of the model, but can also be present in kinetic terms. In such a case, they can be interpreted as a non-trivial structure of the space of fields. Non-vanishing curvature of this space can lead, if negative, to a new phenomenon called geometrical destabilization.
For example, $\alpha$-attractors are...
If Dark Matter is produced via the freeze-in mechanism during a period of early matter domination, the required portal coupling is enhanced to compensate for the faster expansion of the Universe—especially when the reheating temperature is low. This can lead to experimentally testable scenarios. Moreover, any theory involving scalar Dark Matter naturally includes self-interactions, which...
We investigate the capture of fermionic dark matter by neutron stars in scenarios where the dark matter interacts with leptons via a pseudoscalar mediator that violates lepton flavor in the $\mu$–$e$ sector. We demonstrate that such interactions can lead to significant heating of the star, potentially raising its surface temperature to $\sim!2000,\mathrm{K}$. This level of heating may be...
