Mikko O. J. Laine

Learn More
We determine the 2-loop effective gauge coupling of QCD at high temperatures, defined as a matching coefficient appearing in the dimensionally reduced effective field theory. The result allows to improve on one of the classic non-perturbative probes for the convergence of the weak-coupling expansion at high temperatures, the comparison of full and effective(More)
3d lattice studies have recently attracted a lot of attention, especially in connection with finite temperature field theories. One ingredient in these studies is a perturbative computation of the 2-loop lattice counterterms, which are exact in the continuum limit. We extend previous such results to SU(N) gauge theories with Higgs fields in the fundamental(More)
We study to what extent the three-dimensional SU(N) + adjoint Higgs theory can be used as an effective theory for finite temperature SU(N) gauge theory, with N = 2, 3. The parameters of the 3d theory are computed in 2-loop perturbation theory in terms of T /Λ MS , N, N f. The perturbative effective potential of the 3d theory is computed to two loops for N =(More)
We determine the static potential for a heavy quark-antiquark pair propagating in Minkowski time at finite temperature, to leading non-trivial order in Hard Thermal Loop resummed perturbation theory. The result clarifies which Debye-screened potential should be used in models that attempt to describe the " melting " of heavy quarkonium at high temperatures.(More)
It has been suggested recently that in the presence of suitably " warped " extra dimensions , the low-energy limit of pure gauge field theory may contain massive elementary vector bosons localised on a " brane " , but no elementary Higgs scalars. We provide non-perturbative evidence in favour of this conjecture through numerical lattice measurements of the(More)
We formulate the rules for dimensional reduction of a generic nite temperature gauge theory to a simpler three-dimensional eeective bosonic theory in terms of a matching of Green's functions in the full and the eeective theory, and present a computation of a generic set of 1-and 2-loop graphs needed for the application of these rules. As a concrete(More)
We study on the lattice the 3d SU(2)+Higgs model, which is an effective theory of a large class of 4d high temperature gauge theories. Using the exact constant physics curve, continuum (V → ∞, a → 0) results for the properties of the phase transition (critical temperature, latent heat, interface tension) are given. The 3-loop correction to the effective(More)
We provide non-perturbative evidence for the fact that there is no hot electroweak phase transition at large Higgs masses, m H = 95, 120 and 180 GeV. This means that the line of first order phase transitions separating the symmetric and broken phases at small m H has an end point m H,c. In the minimal standard electroweak theory 70 GeV < m H,c < 95 GeV and(More)
We investigate a new numerical procedure to compute fermionic correlation functions at very small quark masses. Large statistical fluctuations, due to the presence of local " bumps " in the wave functions associated with the low-lying eigenmodes of the Dirac operator, are reduced by an exact low-mode averaging. To demonstrate the feasibility of the(More)