Speaker
Description
We study the high-temperature behavior of the electroweak sector of the Standard Model Effective Field Theory (SMEFT), including dimension-six operators, by performing dimensional reduction up to $\mathcal{O}(g^4)$ in the gauge couplings. Our derivation accounts for one-loop corrections to kinetic terms and scalar quartic couplings, as well as two-loop contributions to thermal mass parameters. The latter include effects from purely bosonic operators and from four-fermion interactions. The resulting three-dimensional theory provides a suitable framework for non-perturbative investigations of the thermal history of the early universe within the SMEFT. In particular, we discuss how existing lattice results can be employed to assess the viability of a phase transition in this extended setup, even in the absence of modifications to the vacuum structure at zero temperature.