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Physical Sciences and Mathematics Commons

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Astrophysics and Astronomy

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Cosmology

2003

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Phantom Energy: Dark Energy With W < − 1 Causes A Cosmic Doomsday, Robert R. Caldwell, Marc Kamionkowski, Nevin N. Weinberg Aug 2003

Phantom Energy: Dark Energy With W < − 1 Causes A Cosmic Doomsday, Robert R. Caldwell, Marc Kamionkowski, Nevin N. Weinberg

Dartmouth Scholarship

We explore the consequences that follow if the dark energy is phantom energy, in which the sum of the pressure and energy density is negative. The positive phantom-energy density becomes infinite in finite time, overcoming all other forms of matter, such that the gravitational repulsion rapidly brings our brief epoch of cosmic structure to a close. The phantom energy rips apart the Milky Way, solar system, Earth, and ultimately the molecules, atoms, nuclei, and nucleons of which we are composed, before the death of the Universe in a “big rip.”


Observational Constraints On General Relativistic Energy Conditions, Cosmic Matter Density And Dark Energy From X-Ray Clusters Of Galaxies And Type-La Supernovae, P. Schuecker, R. R. Caldwell, H. Böhringer, C. A. Collins Feb 2003

Observational Constraints On General Relativistic Energy Conditions, Cosmic Matter Density And Dark Energy From X-Ray Clusters Of Galaxies And Type-La Supernovae, P. Schuecker, R. R. Caldwell, H. Böhringer, C. A. Collins

Dartmouth Scholarship

New observational constraints on the cosmic matter density Ωm and an effectively redshift-independent equation

of state parameter wx of the dark energy are obtained while simultaneously testing the strong and null energy conditions of

general relativity on macroscopic scales. The combination of REFLEX X-ray cluster and type-Ia supernova data shows that

for a flat Universe the strong energy condition might presently be violated whereas the null energy condition seems to be

fulfilled. This provides another observational argument for the present accelerated cosmic expansion and the absence of exotic

physical phenomena related to a broken null energy condition. The marginalization of …