Particle theory

Abstract:

We present a model of inflation based on a racetrack model without flux stabilization. The initial conditions are set automatically through topological inflation. This ensures that the dilaton is not swept to weak coupling through either thermal effects or fast roll. Including the effect of non-dilaton fields we find that moduli provide natural candidates for the inflaton. The resulting potential generates slow-roll inflation without the need to fine-tune parameters. The energy scale of inflation must be near the GUT scale and the scalar density perturbation generated has a spectrum consistent with WMAP data. © 2006.

Abstract:

We use lattice techniques to calculate the continuum string tensions of SU (N) gauge theories in 2 + 1 dimensions. We attempt to control all systematic errors at a level that allows us to perform a precise test of the analytic prediction of Karabali, Kim and Nair. We find that their prediction is within 3% of our values for all N and that the discrepancy decreases with increasing N. When we extrapolate our results to N = ∞ we find that there remains a discrepancy of ≃ 1 %, which is a convincing ∼ 6 σ effect. Thus, while the Karabali-Nair analysis is remarkably accurate at N = ∞, it is not exact. © 2006 Elsevier B.V. All rights reserved.