Gauge theories at finite temperature exhibit a rigorous scale hierarchy and their bosonic sector is rendered non-perturbative in the infrared. To reliably describe the thermodynamics of a hot electroweak phase transition both perturbative and non-perturbative methods are needed. At the intersection between these methods, one can construct a three-dimensional effective theory (3d EFT) that...

Effective potential is a standard tool to analyze thermal phase transitions. It is known that perturbative expansion at zero temperature breaks down at high temperature due to infrared divergence. To cure this problem, thermal resummation is indispensable. However, the renormalization group (RG) invariance that is present at zero temperature is lost by such a thermal resummation. In this talk,...

The bubble wall velocity in first-order cosmological phase transitions is crucial for phenomenological studies of, for example, the production of stochastic gravitational waves and electroweak baryogenesis. It is commonly expected that a friction force on the bubble wall can only arise from out-of-equilibrium effects. In this talk, I will discuss the bubble wall motion in local thermal...

We present a novel mechanism which leads to the baryon asymmetry generation during the strong first order phase transition. If the bubble wall propagates with ultra-relativistic velocities, it has been shown that it can produce states much heavier than the scale of the transition and that those states are then out-of-equilibrium. In this paper, we show that the production mechanism can also...

In this talk, I will show that primordial black holes can be formed by bubble collisions if colliding bubbles are super-horizon-sized and not run-away. The PBH abundance can be estimated by counting the number of such collisions of large bubbles for a given first-order phase transition. As a quick example, we use an effective parameters of first-order phase transitions and show that various...

We propose a scenario where superheavy dark matter (DM) can be produced via symmetry restoration first-order phase transition during inflation triggered by the evolution of the inflaton field. The phase transition happens in a spectator sector coupled to the inflaton field. During the phase transition, the spectator field tunnels from a symmetry-broken vacuum to a symmetry-restored vacuum. The...

First order phase transitions in cosmology are usually assumed to proceed via bubble nucleation in homogeneous spacetime. However, the presence of impurities, or seeds, in the early Universe can provide an additional (catalyzed) channel for the false vacuum decay with enhanced tunneling probability. In this talk we will show how this picture can be realized already in the simplest extension of...

I will report on a project with Ilyas, Tamarit & White where we calculate the non-collisional source for electroweak baryogenesis from flavour-mixing in a two-fermion system. The equations describing this system have been derived by Konstandin, Prokopec and Schmidt in 2004,5. Here, we aim for an analytic approximation to the solution, that has thus far not been derived. The basic approximation...

In most studies of gravitational waves from first order cosmological phase transitions, it is assumed that the released vacuum energy gets transformed either to bubble wall collisions, or to sound waves in the plasma. In this talk, I consider an alternative possibility that has so far not been considered: the released energy gets transferred primarily to feebly interacting particles that do...

Gravitational waves (GW) from cosmological phase transitions bear huge discovery potential and can be probed by planned future space-based GW observatories. Complementary to current and future collider experiments, such GW signatures can offer a powerful probe for beyond the Standard Model physics. Predictions for stochastic GW spectrum of a cosmological origin are often plagued by large...