Showing 1 - 10 of 12
The cosmological evolution of the string landscape is expected to consist of multiple stages of old inflation with a large cosmological constant, each of which ends by tunneling. Old inflation has a well-known graceful exit problem as the observable universe becomes empty, devoid of any entropy....
Persistent link: https://www.econbiz.de/10009433398
Quintessential inflation is studied using a string modulus as the inflaton–quintessence field. The modulus begins its evolution at the steep part of its scalar potential, which is due to non-perturbative effects (e.g. gaugino condensation). It is assumed that the modulus crosses an enhanced...
Persistent link: https://www.econbiz.de/10009433585
This paper investigates the nature of model error in complex deterministic nonlinear systems such as weather forecasting models. Forecasting systems incorporate two components, a forecast model and a data assimilation method. The latter projects a collection of observations of reality into a...
Persistent link: https://www.econbiz.de/10009439910
Operational weather forecasts now allow two week probabilistic forecasts of wave height. This paper discusses methods for generating such forecasts from numerical model output from the European Centre for Medium Range Weather Forecasting Ensemble Prediction System. The ECMWF system produces...
Persistent link: https://www.econbiz.de/10009439935
We demonstrate a method for integrating environmental effects into a computable general equilibrium model. This is a critical step forward toward the development of improved integrated assessment models of environmental change. We apply the method to examine the economic consequences of air...
Persistent link: https://www.econbiz.de/10009440552
Although structural constraints such as model order and time delay have been incorporated in the continuous time system identification since its origin, the constraints on the estimated model parameters were rarely enforced. This paper proposes a continuous time system identification approach...
Persistent link: https://www.econbiz.de/10009455550
We propose a class of models in which the η-problem of supersymmetric hybrid inflation is resolved using a Heisenberg symmetry, where the associated modulus field is stabilized and made heavy with the help of the large vacuum energy during inflation without any fine-tuning. The proposed class...
Persistent link: https://www.econbiz.de/10009457931
Integral models for heavy gas dispersion approximate a dispersing cloud in terms of a small number of variables; each of these is ultimately a function of an independent variable which is usually time (instantaneous releases) or downwind distance (continuous releases).This type of model is used...
Persistent link: https://www.econbiz.de/10009458008
We propose an entirely new class of particle physics models of inflation based on the phase transition associated with the spontaneous breaking of family symmetry responsible for the generation of the effective quark and lepton Yukawa couplings. We show that the Higgs fields responsible for the...
Persistent link: https://www.econbiz.de/10009458138
Objectives: If the negligence of an employer results in the disability in an employee, the employer is responsible, in whole or in part, for the disability. The employer is wholly responsible when the worker would not have developed the disability if the employer had taken all reasonable...
Persistent link: https://www.econbiz.de/10009458257