arXiv subjects

A. Jakovac

Publications and source records attributed to A. Jakovac.

58 records · Page 4Linked to original sources

arXiv1997

Classical Statistical Mechanics and Landau Damping

We study the retarded response function in scalar $ϕ^4$-theory at finite temperature. We find that in the high-temperature limit the imaginary part of the self-energy is given by the classical theory to leading order in the coupling. In particular the plasmon damping rate is a purely classical effect to leading order, as shown by Aarts and Smit. The dominant contribution to Landau damping is given by the propagation of classical fields in a heat bath of non-interacting fields.

hep-ph↗

arXiv1996

Partial Path Integration of Quantum Fields: Two-Loop Analysis of the SU(2) Gauge-Higgs Model at Finite Temperature

High temperature reduction of the SU(2) Higgs model is realised by partially integrating its partition function. Various approximate forms of the effective theory resulting from the integration over nonstatic fields and the static electric potential are analysed. Also non-polynomial and non-local terms are allowed. Consistency of the perturbative solution is ensured by new types of induced counterterms. Perturbative phase transition characteristics are presented in the Higgs mass range 30-120 GeV, and compared to results of other perturbative approaches.

hep-ph↗

arXiv1995

Controlling a Non-Polynomial Reduced Finite Temperature Action in the U(1) Higgs Model

An effective theory is constructed for the scalar electrodynamics via 2-loop integration over all non-static fields and the screened electric component of the vector-potential. Non-polynomial terms of the action are preserved and included into the 2-loop calculation of the effective potential of the reduced theory. Also the inclusion of some non-local terms is shown to be important. The effect of non-polynomial operators on the symmetry restoring phase transition is quantitatively compared to results from a local, superrenormalisable approximate effective theory.

hep-ph↗

arXiv1995

Spin and Gauge Systems on Spherical Lattices

We present results for 2D and 4D systems on lattices with topology homotopic to the surface of a (hyper) sphere $S^2$ or $S^4$. Finite size scaling is studied in situations with phase transitions of first and second order type. The Ising and Potts models exhibit the expected behaviour; for the 4D pure gauge $U(1)$ theory we find consistent scaling indicative of a second order phase transition with critical exponent $ν\simeq 0.36(1)$.

hep-lat↗