No Arabic abstract
Photon operators with the proper $J^{PC}$ quantum numbers are constructed, including one made of elementary plaquettes. In compact U(1) lattice gauge theory, these explicit photon operators are shown to permit direct confirmation of the massive and massless states on each side of the phase transition. In the abelian Higgs model, these explicit photon operators avoid some excited state contamination seen with the traditional composite operator, and allow more detailed future studies of the Higgs mechanism.
We define a class of machine-learned flow-based sampling algorithms for lattice gauge theories that are gauge-invariant by construction. We demonstrate the application of this framework to U(1) gauge theory in two spacetime dimensions, and find that near critical points in parameter space the approach is orders of magnitude more efficient at sampling topological quantities than more traditional sampling procedures such as Hybrid Monte Carlo and Heat Bath.
In this work we report on the Landau gauge photon propagator computed for pure gauge 4D compact QED in the confined and deconfined phases and for large lattices volumes: $32^4$, $48^4$ and $96^4$. In the confined phase, compact QED develops mass scales that render the propagator finite at all momentum scales and no volume dependence is observed for the simulations performed. Furthermore, for the confined phase the propagator is compatible with a Yukawa massive type functional form. For the deconfined phase the photon propagator seems to approach a free field propagator as the lattice volume is increased. In both cases, we also investigate the static potential and the average value of the number of Dirac strings in the gauge configurations $m$. In the confined phase the mass gap translates into a linearly growing static potential, while in the deconfined phase the static potential approaches a constant at large separations. Results shows that $m$ is, at least, one order of magnitude larger in the confined phase and confirm that the appearance of a confined phase is connected with the topology of the gauge group.
A conceptually simple model for strongly interacting compact U(1) lattice gauge theory is expressed as operators acting on qubits. The number of independent gauge links is reduced to its minimum through the use of Gausss law. The model can be implemented with any number of qubits per gauge link, and a choice as small as two is shown to be useful. Real-time propagation and real-time collisions are observed on lattices in two spatial dimensions. The extension to three spatial dimensions is also developed, and a first look at 3-dimensional real-time dynamics is presented.
We discuss the lattice formulation of the t Hooft surface, that is, the two-dimensional surface operator of a dual variable. The t Hooft surface describes the world sheets of topological vortices. We derive the formulas to calculate the expectation value of the t Hooft surface in the multiple-charge lattice Abelian Higgs model and in the lattice non-Abelian Higgs model. As the first demonstration of the formula, we compute the intervortex potential in the charge-2 lattice Abelian Higgs model.
We perform the Monte Carlo study of the SU(3) non-Abelian Higgs model. We discuss phase structure and non-Abelian vortices by gauge invariant operators. External magnetic fields induce non-Abelian vortices in the color-flavor locked phase. The spatial distribution of non-Abelian vortices suggests the repulsive vortex-vortex interaction.