Anisotropic k-essence cosmologies

doi:10.1103/PHYSREVD.73.063502

Title: Anisotropic k-essence cosmologies

Full Record
Other Related Research

Abstract

We investigate a Bianchi type-I cosmology with k-essence and find the set of models which dissipate the initial anisotropy. There are cosmological models with extended tachyon fields and k-essence having a constant barotropic index. We obtain the conditions leading to a regular bounce of the average geometry and the residual anisotropy on the bounce. For constant potential, we develop purely kinetic k-essence models which are dust dominated in their early stages, dissipate the initial anisotropy, and end in a stable de Sitter accelerated expansion scenario. We show that linear k-field and polynomial kinetic function models evolve asymptotically to Friedmann-Robertson-Walker cosmologies. The linear case is compatible with an asymptotic potential interpolating between V{sub l}{proportional_to}{phi}{sup -{gamma}{sub l}}, in the shear dominated regime, and V{sub l}{proportional_to}{phi}{sup -2} at late time. In the polynomial case, the general solution contains cosmological models with an oscillatory average geometry. For linear k-essence, we find the general solution in the Bianchi type-I cosmology when the k field is driven by an inverse square potential. This model shares the same geometry as a quintessence field driven by an exponential potential.

Authors:

Chimento, Luis P.; Forte, Monica ^[1]

Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)

Publication Date:: 2006-03-15

OSTI Identifier:: 20782606

Resource Type:: Journal Article

Journal Name:: Physical Review. D, Particles Fields

Additional Journal Information:: Journal Volume: 73; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevD.73.063502; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821

Country of Publication:: United States

Language:: English

Subject:: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANISOTROPY; COSMOLOGICAL MODELS; COSMOLOGY; DE SITTER GROUP; DUSTS; GEOMETRY; MATHEMATICAL SOLUTIONS; NONLUMINOUS MATTER; POLYNOMIALS; POTENTIALS; SHEAR

Citation Formats


                    Chimento, Luis P., and Forte, Monica. Anisotropic k-essence cosmologies.  United States: N. p., 2006. 
        Web.  doi:10.1103/PHYSREVD.73.063502.

Copy to clipboard


                    Chimento, Luis P., & Forte, Monica. Anisotropic k-essence cosmologies.  United States.  doi:10.1103/PHYSREVD.73.063502.

Copy to clipboard


                    Chimento, Luis P., and Forte, Monica. Wed .  
        "Anisotropic k-essence cosmologies".  United States.  doi:10.1103/PHYSREVD.73.063502.

Copy to clipboard


                    
@article{osti_20782606,

  title        = {Anisotropic k-essence cosmologies},

  author       = {Chimento, Luis P. and Forte, Monica},

  abstractNote = {We investigate a Bianchi type-I cosmology with k-essence and find the set of models which dissipate the initial anisotropy. There are cosmological models with extended tachyon fields and k-essence having a constant barotropic index. We obtain the conditions leading to a regular bounce of the average geometry and the residual anisotropy on the bounce. For constant potential, we develop purely kinetic k-essence models which are dust dominated in their early stages, dissipate the initial anisotropy, and end in a stable de Sitter accelerated expansion scenario. We show that linear k-field and polynomial kinetic function models evolve asymptotically to Friedmann-Robertson-Walker cosmologies. The linear case is compatible with an asymptotic potential interpolating between V{sub l}{proportional_to}{phi}{sup -{gamma}{sub l}}, in the shear dominated regime, and V{sub l}{proportional_to}{phi}{sup -2} at late time. In the polynomial case, the general solution contains cosmological models with an oscillatory average geometry. For linear k-essence, we find the general solution in the Bianchi type-I cosmology when the k field is driven by an inverse square potential. This model shares the same geometry as a quintessence field driven by an exponential potential.},

  doi          = {10.1103/PHYSREVD.73.063502},

  journal      = {Physical Review. D, Particles Fields},

  issn         = {0556-2821},

  number       = 6,

  volume       = 73,

  place        = {United States},

  year         = {2006},

  month        = {3}

}

Copy to clipboard

Journal Article:

DOI: 10.1103/PHYSREVD.73.063502

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Atypical k-essence cosmologies

Journal Article Chimento, Luis P. ; Lazkoz, Ruth - Physical Review. D, Particles Fields

We analyze the implications of having a divergent speed of sound in k-essence cosmological models. We first study a known theory of that kind, for which the Lagrangian density depends linearly on the time derivative of the k-field. We show that when k-essence is the only source consistency requires that the potential of the k-field be of the inverse square form. Then, we review the known result that the corresponding power-law solutions can be mapped to power-law solutions of theories with no divergence in the speed of sound. After that, we argue that the requirement of a divergent sound speedmore »« less
DOI: 10.1103/PhysRevD.71.023505
Stability of phantom k-essence theories

Journal Article Abramo, L. Raul ; Pinto-Neto, Nelson ; ICRA-Centro Brasileiro de Pesquisas Fisicas, R. Xavier Sigaud 150, 22290-180, Rio de Janeiro - Physical Review. D, Particles Fields

We show that phantom dark energy, if it is described by a k-essence theory, has three fundamental problems: first, its Hamiltonian is unbounded from below. Second, classical stability precludes the equation of state from crossing the 'Lambda-barrier', w{sub {lambda}}=-1. Finally, both the equation of state and the sound speed are unbounded - the first, from below, the second, from above - if the kinetic term is not bounded by dynamics.
DOI: 10.1103/PHYSREVD.73.063522
No-Go Theorem for k-Essence Dark Energy

Journal Article Bonvin, Camille ; Caprini, Chiara ; Durrer, Ruth - Physical Review Letters

We demonstrate that if k-essence can solve the coincidence problem and play the role of dark energy in the Universe, the fluctuations of the field have to propagate superluminally at some stage. We argue that this implies that successful k-essence models violate causality. It is not possible to define a time ordered succession of events in a Lorentz invariant way. Therefore, k-essence cannot arise as a low energy effective field theory of a causal, consistent high energy theory.
DOI: 10.1103/PHYSREVLETT.97.081303
Tracking quintessence and k-essence in a general cosmological background

Journal Article Das, Rupam ; Kephart, Thomas W. ; Scherrer, Robert J. - Physical Review. D, Particles Fields

We derive conditions for stable tracker solutions for both quintessence and k-essence in a general cosmological background, H{sup 2}{proportional_to}f({rho}). We find that tracker solutions are possible only when {eta}{identical_to}dlnf/dln{rho}{approx_equal}constant, aside from a few special cases, which are enumerated. Expressions for the quintessence or k-essence equation of state are derived as a function of {eta} and the equation of state of the dominant background component.
DOI: 10.1103/PHYSREVD.74.103515
Fine-tuning free paradigm of two-measures theory: k-essence, absence of initial singularity of the curvature, and inflation with graceful exit to the zero cosmological constant state

Journal Article Guendelman, E. I. ; Kaganovich, A. B. - Physical Review. D, Particles Fields

The dilaton-gravity sector of the two-measures field theory (TMT) is explored in detail in the context of spatially flat Friedman-Robertson-Walker (FRW) cosmology. The model possesses scale invariance which is spontaneously broken due to the intrinsic features of the TMT dynamics. The dilaton {phi} dependence of the effective Lagrangian appears only as a result of the spontaneous breakdown of the scale invariance. If no fine-tuning is made, the effective {phi}-Lagrangian p({phi},X) depends quadratically upon the kinetic term X. Hence TMT represents an explicit example of the effective k-essence resulting from first principles without any exotic term in the underlying action intendedmore »« less
DOI: 10.1103/PHYSREVD.75.083505

Similar Records