Two Resonant Quantum Electrodynamics Models of Quantum Measuring Systems

A quantum measurement scheme is suggested in two resonant models of quantum electrodynamics. The first model is the brain, where, for the propagation of its action potentials, the free electron laser-like coherence mechanism recently investigated by the author is comprehensively applied. The second model is an assembly of Preparata et al.'s coherence domains, in which we incorporate the quantum field theory of memory advocated by Umezawa et al. These two models are remarkably analogous.Comment: v3: 35 pages, 5 figures, published versio

Non-Abelian Monopoles, Vortices and Confinement

Three closely related issues will be discussed. Magnetic quarks having non-Abelian charges have been found recently to appear as the dominant infrared degrees of freedom in some vacua of softly broken N=2 supersymmetric QCD with SU(n_c) gauge group. Their condensation upon N=1 perturbation causes confinement and dynamical symmetry breaking. We argue that these magnetic quarks can be naturally related to the semiclassical non-Abelian monopoles of the type first discussed by Goddard, Nuyts, Olive and E. Weinberg. We discuss also general properties of non-Abelian vortices and discuss their relevance to the confinement in QCD. Finally, calculation by Douglas and Shenker of the tension ratios for vortices of different N-alities in the softly broken N=2 supersymmetric SU(N) Yang-Mills theory, is carried to the second order in the adjoint multiplet mass. A correction to the ratios violating the sine formula is found, showing that the latter is not a universal quantity.Comment: Latex 19 pages, 3 figures, Talk at Continuous Advance in QCD (Arkady Fest), Minneapolis, May 200

Modeling Quantum Mechanical Observers via Neural-Glial Networks

We investigate the theory of observers in the quantum mechanical world by using a novel model of the human brain which incorporates the glial network into the Hopfield model of the neural network. Our model is based on a microscopic construction of a quantum Hamiltonian of the synaptic junctions. Using the Eguchi-Kawai large N reduction, we show that, when the number of neurons and astrocytes is exponentially large, the degrees of freedom of the dynamics of the neural and glial networks can be completely removed and, consequently, that the retention time of the superposition of the wave functions in the brain is as long as that of the microscopic quantum system of pre-synaptics sites. Based on this model, the classical information entropy of the neural-glial network is introduced. Using this quantity, we propose a criterion for the brain to be a quantum mechanical observer.Comment: 24 pages, published versio

Non-Abelian Superconductors - Lessons from Supersymmetric Gauge Theories for QCD

Much about the confinement and dynamical symmetry breaking in QCD might be learned from models with supersymmetry. In particular, models based on N=2 supersymmetric theories with gauge groups SU(N), SO(N) and $USp(2 N)$ and with various number of flavors, give deep dynamical hints about these phenomena. For instance, the BPS non-abelian monopoles can become the dominant degrees of freedom in the infrared due to quantum effects. Upon condensation (which can be triggered in these class of models by perturbing them with an adjoint scalar mass) they induce confinement with calculable pattern of dynamical symmetry breaking. This may occur either in a weakly interacting regime or in a strongly coupled regime (in the latter, often the low-energy degrees of freedom contain relatively non-local monopoles and dyons simultaneously and the system is near a nontrivial fixed-point). Also, the existence of sytems with BPS {\it non-abelian vortices} has been shown recently. These results point toward the idea that the ground state of QCD is a sort of dual superconductor of non-abelian variety.Comment: Latex file, 11 eps figures, Talk at the "Confinement 2003", Riken, Tokyo, July 200

Quantum Nonabelian Monopoles

We discuss quantum mechanical and topological aspects of nonabelian monopoles. Related recent results on nonabelian vortices are also mentioned.Comment: Latex 13 pages, 2 figures, Talk at "Continuous Advances in QCD 2004", Univ. Minnesota, May 200

Confinement, NonAbelian monopoles, and 2D CP(N-1) model on the worldsheet of finite-length strings

Quark confinement is proposed to be a dual Meissner effect of nonAbelian kind. Important hints come from physics of strongly-coupled infrared-fixed-point theories in N=2 supersymmetric QCD, which turn into confining vacua under a small relevant perturbation. The quest for the semiclassical origin of the nonAbelian monopoles, ubiquitous as the infrared degrees of freedom in supersymmetric gauge theories, motivates us to study the quantum dynamics of 2D CP(N-1)model defined on a finite-width worldstrip, with various boundary conditions. The model is found to possess a unique phase ("confinement phase"), independent of the length of the string, showing the quantum persistence of the nonAbelian monopole.Comment: Latex 14 pages 4 figure