Kasner and mixmaster behavior in universes with equation of state w >= 1

By J. Erickson, Daniel H. Wesley, Paul J. Steinhardt, N. Turok. 2003

239 citations recorded by the source corpus.

We consider cosmological models with a scalar field with equation of state $w\ge 1$ that contract towards a big crunch singularity, as in recent cyclic and ekpyrotic scenarios. We show that chaotic mixmaster oscillations due to anisotropy and curvature are suppressed, and the contraction is described by a homogeneous and isotropic Friedmann equation if $w>1$. We generalize the results to theories where the scalar field couples to p-forms and show that there exists a finite value of $w$, depending on the p-forms, such that chaotic oscillations are suppressed. We show that $Z_2$ orbifold compactification also contributes to suppressing chaotic behavior. In particular, chaos is avoided in contracting heterotic M-theory models if $w>1$ at the crunch.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/3b6cc40b494ac34164bdca7f1a6ebfda6233137c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Robert Brandenberger
2. Yi-Fu Cai
3. P. Peter
4. F. Piazza
5. J. Khoury
6. J. Lehners
7. L. Senatore
8. P. Creminelli

In Nuclear and High Energy Physics

1. Robert Brandenberger
2. Yi-Fu Cai
3. P. Peter
4. J. Khoury
5. J. Lehners
6. F. Piazza
7. G. Horowitz
8. L. Senatore

Citations in the corpus

• Exploring bouncing cosmologies with cosmological surveys (2014, background): “However, this issue is avoided in the ekpyrotic scenario where a scalar field with a steep and negative-valued potential always dominates over anisotropies in a contracting universe [77] and so it is justified to neglect anisotropies in the presence of an ekpyrotic scalar field.”
• Ekpyrotic and cyclic cosmology (2008, background): “Now it is clear how the ekpyrotic phase can avoid the uncertainties of a chaotic crunch: even when dangerous modes are present their energy density gets diluted to such an extent during ekpyrosis that they don’t have time to come to dominate before less than a Planck time before the big crunch 4 [36”
• A smooth bouncing cosmology with scale invariant spectrum (2007, background): “Also curvature and anisotropies become irrelevant, as the energy density increases with the scale factor faster than a−6 [29].”
• Rapidly-Varying Speed of Sound, Scale Invariance and Non-Gaussian Signatures (2008, background): “Indeed, ekpyrotic contraction is equally powerful as inflation in solving the homogeneity, isotropy and flatness problems of standard big bang cosmology [2, 38].”
• Holographic description of AdS cosmologies (2005, background): “This relation will have to include the fact that our truncated theory of four dimensional gravity coupled to a scalar does not exhibit this chaotic behavior [38, 39].”
• Bouncing Cosmologies: Progress and Problems (2016, background): “Indeed, although the ekpyrotic phase permits to avoid the BKL instability in the flat case [158], the presence of curvature could spoil the picture through a mixmaster phenomenon.”