Current observational constraints on cosmic doomsday

Observational Bounds on Cosmic Doomsday

Observational constraints on cosmic string production during brane inflation

Overall, brane inflation is compatible with the recent analysis of the Wilkinson microwave anisotropy probe ~WMAP! data. Here we explore the constraints of WMAP and the 2dF Galaxy Redshift Survey ~2dFGRS! data on the various brane inflationary scenarios. Brane inflation naturally ends with the production of cosmic strings, which may provide a way to distinguish these models observationally. We ...

Current observational constraints on holographic dark energy model

We consider the cosmological constraints on the holographic dark energy model by using the data set available from the type Ia supernovae (SNIa), CMB and BAO observations. The constrained parameters are critical to determine the quintessence or quintom character the model. The SNIa and joint SNIa+CMB+BAO analysis give the best-fit results for β with priors on Ωm0 and ω0. Using montecarlo we obt...

Forecasting cosmic doomsday from CMB-LSS cross-correlations

A broad class of dark energy models, which have been proposed in attempts at solving the cosmological constant problems, predict a late time variation of the equation of state with redshift. The variation occurs as a scalar field picks up speed on its way to negative values of the potential. The negative potential energy eventually turns the expansion into contraction and the local universe und...

Notes on "doomsday models".

I would like to state, briefly and bluntly, why I think the various "Doomsday Models" are worthless as science and as guides to public policy. I hope it will not be deduced that I believe the problems of population control, environmental degradation, and resource exhaustion to be unimportant, or that I think an adequate response to them is a vague confidence that something will turn up. They ar...