Title: Baryogenesis Computation — from LTE to Real-Time Dynamics

Tuesday, 15 September 2026 at 10:45

Baryogenesis is a mechanism that generates the matter-antimatter asymmetry of the Universe through dynamical processes. For the asymmetry to be generated and preserved, the dynamical processes must be out of thermal equilibrium. Focusing on one particular mechanism—Electroweak Baryogenesis—the baryon asymmetry is generated through a first-order electroweak phase transition, where expanding bubbles of the broken phase interact with the surrounding plasma. Predicting the resulting baryon asymmetry therefore requires understanding both bubble wall dynamics and wall–plasma interactions, both of which are intrinsically non-equilibrium dynamics. Conventional calculations taking the out-of-equilibrium effects into account are convoluted and computationally demanding, while studies haven shown that the bubble wall dynamics are dominantly controlled by the local thermal equilibrium (LTE) effects. In this talk, I will present a simplified framework for computing the bubble wall velocity in the LTE approximation. For the generation of CP and baryon asymmetries, however, genuinely out-of-equilibrium dynamics are essential. Motivated by advances in quantum simulation, I will also present our first steps toward a real-time description of fermion scattering from a bubble wall—the microscopic source of CP asymmetry in electroweak baryogenesis. Using tensor network methods as a proxy for future fault-tolerant quantum simulations, this approach provides a complementary route toward studying baryogenesis directly in real time.