Investigating BSM Models with Large Scale Separation

Mass-split systems based on a conformal infrared fixed point provide a low-energy effective description of beyond the standard model systems with large scale separation. We report results of exploratory investigations with four light and eight heavy flavors using staggered fermions, and up to five different values for the light flavor mass, five different heavy flavor masses, and two values of the bare gauge coupling.Comment: 8 pages, 7 figures; Talk presented at the 35th International Symposium on Lattice Field Theory, 18 - 24 June 2017, Granada, Spai

Characterization of phases and boundary effects in U(1) gauge theory

We show that the two phases of the 4-dimensional compact U(1) lattice gauge theory are characterized by the existence or absence of an infinite current network, defining ``infinite'' on a finite lattice in a manner appropriate to the chosen boundary conditions. In addition for open and fixed boundary conditions we demonstrate the effects of inhomogeneities and provide examples of the reappearance of an energy gap.Comment: 5 pages, 5 figures included, uuencoded postscript file. Contribution to LATTICE 9

Critical properties and monopoles in U(1) lattice gauge theory

We present a detailed study of the properties of the phase transition in the four-dimensional compact U(1) lattice gauge theory supplemented by a monopole term, for values of the monopole coupling $\lambda$ such that the transition is of second order. By a finite size analysis we show that at $\lambda= 0.9$ the critical exponent is already characteristic of a second-order transition. Moreover, we find that this exponent is definitely different from the one of the Gaussian case. We further observe that the monopole density becomes approximately constant in the second-order region. Finally we reveal the unexpected phenomenon that the phase transition persists up to very large values of $\lambda$, where the transition moves to (large) negative $\beta$.Comment: 14 pages, LaTeX, 5 figure