Type I singularities and the Phantom Menace
نویسنده
چکیده
We consider the future dynamics of a transient phantom dominated phase of the universe in LQC and in the RS braneworld, which both have a non-standard Friedmann equation. We find that for a certain class of potentials, the Hubble parameter oscillates with simple harmonic motion in the LQC case and therefore avoids any future singularity. For more general potentials we find that damping effects eventually lead to the Hubble parameter becoming constant. On the other hand in the braneworld case we find that although the type I singularity can be avoided, the scale factor still diverges at late times.
منابع مشابه
بررسی شکافتگی کوچک و دیگر تکینگیهای آینده عالم و برقراری قانون دوم ترمودینامیک در نظریه
The future singularities are possible in a universe that is described by F(R) theory. In previous studies the occurrence of the singularities in F(R) theory have been considered by using a special function for the Hubble parameter and calculating the F(R) function for each of the singularities. Using the specified Hubble parameter causes some difficulties in the study of the second law of therm...
متن کاملThe Phantom Menace
Sodium-Calcium Exchange : The Phantom Menace Print ISSN: 0009-7330. Online ISSN: 1524-4571 Copyright © 1999 American Heart Association, Inc. All rights reserved. is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Circulation Research doi: 10.1161/01.RES.85.11.982 1999;85:982-984 Circ Res. http://circres.ahajournals.org/content/85/11/982 World Wide Web at: T...
متن کاملar X iv : a st ro - p h / 06 03 17 1 v 1 7 M ar 2 00 6 Scalar perturbations and the possible self - destruction of the phantom menace
Some analysis of the supernovae type Ia observational data seems to indicate that the Universe today is dominated by a phantom field, for which all energy conditions are violated. Such phantom field may imply a singularity in a future finite time, called big rip. Studying the evolution of scalar perturbations for such a field, we show that if the pressure is negative enough, the Universe can be...
متن کاملDosimetric Parameters Estimation of I-125 Brachytherapy Source in fat phantom using GATE8.0 code
Introduction: Brachytherapy is one type of internal radiation therapy where radiation sources, which are usually encapsulated, are placed as close as possible to the tumor site or inside the patient's body. In this technique, it is important to determine dose distribution around the brachytherapy capsule to create optimal treatment plant. In this way, dosimetric parameters are...
متن کاملA Phantom Menace? Cosmological Consequences of a Dark Energy Component with Super-Negative Equation of State
It is extraordinary that a number of observations indicate that we live in a spatially flat, low matter density Universe, which is currently undergoing a period of accelerating expansion. The effort to explain this current state has focused attention on cosmological models in which the dominant component of the cosmic energy density has negative pressure, with an equation of state w ≥ −1. Remar...
متن کامل