53 research outputs found
Clay content drives carbon stocks in soils under a plantation of Eucalyptus saligna Labill. in southern Brazil
Evaluating guaranteed maximum price and target cost contracting strategies in Hong Kong construction industry
Robustness of inflation to large tensor perturbations
Extending our previous work on the robustness of inflation to perturbations
in the scalar field, we investigate the effects of perturbations in the
transverse traceless part of the extrinsic curvature on the evolution of an
inhomogeneous inflaton field. Focusing on small field models, we show that
these additional metric inhomogeneities initially reduce the total number of
e-folds as the amplitude increases, but that the reduction saturates and even
reverses above a certain amplitude. We present an argument that this is due to
the presence of a large initial Hubble friction when metric perturbations are
large.Comment: 16 pages, 15 figure
The contractor time–cost–credit trade‐off problem: integer programming model, heuristic solution, and business insights
The contribution from hyphae, roots and organic carbon constituents to the aggregation of a sandy loam under long-term clover-based and grass pastures
Internal heat necrosis in the Midatlantic region — Influence of environment and cultural management
The role of fluctuation-dissipation dynamics in setting initial conditions for inflation
We study the problem of initial conditions for slow-roll inflation along a plateau-like scalar potential within the framework of fluctuation-dissipation dynamics. We consider, in particular, that inflation was preceded by a radiation-dominated epoch where the inflaton is coupled to light degrees of freedom and may reach a near-equilibrium state. We show that the homogeneous field component can be sufficiently localized at the origin to trigger a period of slow-roll if the interactions between the inflaton and the thermal degrees of freedom are sufficiently strong and argue that this does not necessarily spoil the flatness of the potential at the quantum level. We further conclude that the inflaton can still be held at the origin after its potential begins to dominate the energy balance, leading to a period of thermal inflation. This then suppresses the effects of nonlinear interactions between the homogeneous and inhomogeneous field modes that could prevent the former from entering a slow-roll regime. Finally, we discuss the possibility of an early period of chaotic inflation, at large field values, followed by a first stage of reheating and subsequently by a second inflationary epoch along the plateau about the origin. This scenario could prevent an early overclosure of the Universe, at the same time yielding a low tensor-to-scalar ratio in agreement with observations.publishe
- …