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Cosmology, Relativity, and Gravity Commons™
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Articles 1 - 2 of 2
Full-Text Articles in Cosmology, Relativity, and Gravity
Limits Of Quintessence, R. R. Caldwell, Eric V. Linder
Limits Of Quintessence, R. R. Caldwell, Eric V. Linder
Dartmouth Scholarship
We present evidence that the simplest particle-physics scalar-field models of dynamical dark energy can be separated into distinct behaviors based on the acceleration or deceleration of the field as it evolves down its potential towards a zero minimum. We show that these models occupy narrow regions in the phase plane of w and w′, the dark energy equation of state and its time derivative in units of the Hubble time. Restricting an energy scale of the dark energy microphysics limits how closely a scalar field can resemble a cosmological constant. These results, indicating a desired measurement resolution of order σ(w′)≈(1+w), …
Phantom Energy: Dark Energy With W < − 1 Causes A Cosmic Doomsday, Robert R. Caldwell, Marc Kamionkowski, Nevin N. Weinberg
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.”