- Wherever possible simple examples, which illustrate the main ideas, are provided before embarking on the actual discussion of the problem of interest - The book introduces the readers to problems of great current interest, like instantons, calorons, vortices, magnetic monopoles - QCD at finite temperature is discussed at great length, both in perturbation theory and in Monte Carlo simulations - The book contains many figures showing numerical results of pioneering work

This volume contains the Proceedings of'the International Workshop "Lattice Gauge Theory 1986", held at Brookhaven National Laboratory, September 15 - 19, 1986. The meeting was the sequel to the one held at Wuppertal in 1985, the Proceedings of which have appeared in the same Plenum series. During the past few years, a considerable number of meetings on lat tice gauge theory have been held, on both sides of the Atlantic. With our workshop, through early planning and coordination with other prospective organizers, we tried to channel this activity into one major yearly meeting. For 1986, these efforts were successful, and it is our hope that a pattern has been set for the coming years. One result, however, was that the number of participants considerably exceeded that normally found at NATO Advanced Research Workshops. This year, a "nucleus" of NATO-supported experts induced a large number of further interested specialists to obtain their own funds - thus greatly amplifying the impact of the event. The topics covered at the workshop ranged from hadron spectra to strong interaction thermo dynamics; they included spontaneous symmetry breaking and Higgs models, renormalization group methods, as well as many contributions on various possible schemes for the simulation of dynamical quarks. First systematic applications of finite size scaling to lattice gauge theory were discussed, and the approach to the continuum limit was considered in detail.

Abstract: In this dissertation I use lattice gauge theory to study models of electroweak symmetry breaking that involve new strong dynamics. Electroweak symmetry breaking (EWSB) is the process by which elementary particles acquire mass. First proposed in the 1960s, this process has been clearly established by experiments, and can now be considered a law of nature. However, the physics underlying EWSB is still unknown, and understanding it remains a central challenge in particle physics today. A natural possibility is that EWSB is driven by the dynamics of some new, strongly-interacting force. Strong interactions invalidate the standard analytical approach of perturbation theory, making these models difficult to study. Lattice gauge theory is the premier method for obtaining quantitatively-reliable, nonperturbative predictions from strongly-interacting theories. In this approach, we replace spacetime by a regular, finite grid of discrete sites connected by links. The fields and interactions described by the theory are likewise discretized, and defined on the lattice so that we recover the original theory in continuous spacetime on an infinitely large lattice with sites infinitesimally close together. The finite number of degrees of freedom in the discretized system lets us simulate the lattice theory using high-performance computing. Lattice gauge theory has long been applied to quantum chromodynamics, the theory of strong nuclear interactions. Using lattice gauge theory to study dynamical EWSB, as I do in this dissertation, is a new and exciting application of these methods. Of particular interest is non-perturbative lattice calculation of the electroweak S parameter. Experimentally S [approximate] -0.15(10), which tightly constrains dynamical EWSB. On the lattice, I extract S from the momentum-dependence of vector and axial-vector current correlators. I created and applied computer programs to calculate these correlators and analyze them to determine S . I also calculated the masses and other properties of the new particles predicted by these theories. I find S [Special characters omitted.] 0.1 in the specific theories I study. Although this result still disagrees with experiment, it is much closer to the experimental value than is the conventional wisdom S [Special characters omitted.] 0.3. These results encourage further lattice studies to search for experimentally viable strongly-interacting theories of EWSB.

This primer is aimed at elevating graduate students of condensed matter theory to a level where they can engage in independent research. Topics covered include second quantisation, path and functional field integration, mean-field theory and collective phenomena.

Quantum field theory is the application of quantum mechanics to systems with infinitely many degrees of freedom. This 2007 textbook presents quantum field theoretical applications to systems out of equilibrium. It introduces the real-time approach to non-equilibrium statistical mechanics and the quantum field theory of non-equilibrium states in general. It offers two ways of learning how to study non-equilibrium states of many-body systems: the mathematical canonical way and an easy intuitive way using Feynman diagrams. The latter provides an easy introduction to the powerful functional methods of field theory, and the use of Feynman diagrams to study classical stochastic dynamics is considered in detail. The developed real-time technique is applied to study numerous phenomena in many-body systems. Complete with numerous exercises to aid self-study, this textbook is suitable for graduate students in statistical mechanics and condensed matter physics.