Kari Rummukainen

Chern-Simons number diffusion and hard thermal loops on the lattice

We develop a discrete lattice implementation of the hard thermal loop effective action by the method of added auxiliary fields. We use the resulting model to measure the sphaleron rate (topological susceptibility) of Yang-Mills theory at weak coupling. Our results give parametric behavior in accord with the arguments of Arnold, Son, and Yaffe, and are in quantitative agreement with the results of Moors, Hu, and Muller.

Running coupling in SU(2) gauge theory with two adjoint fermions

We study SU(2) gauge theory with two Dirac fermions in the adjoint representation of the gauge group on the lattice. Using clover improved Wilson fermion action with hypercubic truncated stout smearing we perform simulations at larger coupling than before. We measure the evolution of the coupling constant using the step scaling method with the Schrodinger functional and study the remaining discretization effects. At weak coupling we observe significant discretization effects, which make it difficult to obtain a fully controlled continuum limit. Nevertheless, the data remains consistent with the existence of a fixed point in the interval

Non-perturbative computation of the bubble nucleation rate in the cubic anisotropy model

2.2ensuremath{lesssim}{g}^{*2}ensuremath{lesssim}3

JIMWLK evolution of the odderon

. We also measure the anomalous dimension and find that its value at the fixed point is

Form factor and width of a quantum string

{ensuremath{gamma}}^{*}ensuremath{simeq}0.2ifmmodepmelsetextpmfi{}0.03

Gravitational waves from cosmological first order phase transitions

.

Conformal window in SU(2) with fundamental fermions

At first order phase transitions the transition proceeds through droplet nucleation and growth. We discuss a lattice method for calculating the droplet nucleation rate, including the complete dynamical factors. The method is especially suitable for very strongly suppressed droplet nucleation, which is often the case in physically interesting transitions. We apply the method to the 3-dimensional cubic anisotropy model in a parameter range where the model has a radiatively induced strong first order phase transition, and compare the results with analytical approaches.

Momentum broadening of partons on the light cone from the lattice

We study the effects of a parity-odd ``odderon correlation in Jalilian-Marianchar21{}Iancuchar21{}McLerranchar21{}Weigertchar21{}Leonidovchar21{}Kovner renormalization group evolution at high energy. Firstly we show that in the eikonal picture where the scattering is described by Wilson lines, one obtains a strict mathematical upper limit for the magnitude of the odderon amplitude compared to the parity-even Pomeron one. This limit increases with

Renormalization of Polyakov loops in different representations and the large-N limit

{N}_{mathrm{c}}

Spectrum of SU(2) gauge theory with two fermions in the adjoint representation

, approaching infinity in the infinite