Stability of the de-Sitter spacetime. The anisotropic case

Bieniek, Przemysław; Chojnacki, Jan; Kwapisz, Jan; Meissner, Krzysztof A.

doi:10.48550/arxiv.2301.06616

Cited by 2 publications

(2 citation statements)

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“…For the case of an isotropic FLRW Universe the HZ action depends on just a single even function F (H) of the Hubble parameter H(t). Further developments of the HZ approach have been given in several subsequent papers [12][13][14][15][16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

From the string vacuum to FLRW or de Sitter via α' corrections

Conzinu,

Fanizza,

Gasperini

et al. 2023

J. Cosmol. Astropart. Phys.

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We first make more precise a recent “Hamiltonian” reformulation of the Hohm-Zwiebach approach to the tree-level, O(d,d)-invariant string cosmology equations at all orders in the α' expansion, and recall how it allows to give a simple characterization of a large class of cosmological scenarios connecting, through a non-singular bounce, two duality-related perturbative solutions at early and late times. We then discuss the effects of adding to the action a non-perturbative, O(d,d)-breaking, dilaton potential V(ϕ). The resulting cosmological solutions, assumed to approach at early times the perturbative string vacuum (with vanishing curvature and string coupling), can stabilize the dilaton at late times and simultaneously approach either a matter-dominated FLRW cosmology or a de-Sitter-like inflationary phase, depending on initial conditions and on the properties of V(ϕ) at moderate-coupling. We also identify a general mechanism for generating isotropic late-time attractors from a large basin of anisotropic initial conditions.

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Section: Introductionmentioning

confidence: 99%

From the string vacuum to FLRW or de Sitter via α' corrections

Conzinu,

Fanizza,

Gasperini

et al. 2023

J. Cosmol. Astropart. Phys.

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“…In [158,163] solutions of the equations of motion of DFT cosmology from [153,154] coupled to matter obeying the T-duality symmetry were analyzed., and their stability was studied [163]. 6 In [159] (see also [167,168]) it was shown that the formalism of [153,154] (including matter) can be generalized to an anisotropic setting. In particular, we can consider a setup in which matter is initially dominated by winding modes about all spatial dimensions and then undergoes a phase transition in which the winding modes about three (external) dimensions decay into radiation while those about the other six (internal) dimensions persist, as argued to be the case in String Gas Cosmology.…”

Section: Jcap11(2023)019mentioning

confidence: 99%

Superstring cosmology — a complementary review

Brandenberger

2023

J. Cosmol. Astropart. Phys.

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In this review, a number of approaches to superstring cosmology which make use of key features which distinguish string theory from point particle theories are discussed, with particular emphasis on emergent scenarios. One motivation for the discussion is the realization that, in order to describe the evolution of the very early universe, it is necessary to go beyond a conventional effective field theory (EFT) analysis. Some of the conceptual problems of an EFT analysis will be discussed. The review begins with a summary of the criteria for a successful early universe scenario, emphasizing that cosmic inflation is not the only scenario of early universe cosmology which is consistent with current cosmological observations. Bouncing and emergent scenarios as interesting alternatives are introduced. Some realizations of these scenarios from superstring theory are reviewed, e.g. String Gas Cosmology, the Pre-Big-Bang scenario, the Ekpyrotic model, Double Field Theory cosmology and matrix model cosmology. In light of the difficulties in obtaining cosmic inflation from string theory (at the level of EFT), and realizing that there are promising examples of alternative early universe scenarios which are derived from basic principles of superstring theory, one must entertain the possibility that the cosmology emerging from string theory will not involve an extended period of accelerated expansion.

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Stability of the de-Sitter spacetime. The anisotropic case

Cited by 2 publications

References 0 publications

From the string vacuum to FLRW or de Sitter via α' corrections

From the string vacuum to FLRW or de Sitter via α' corrections

Superstring cosmology — a complementary review

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