Stability of singularity-free cosmological solutions in Hořava-Lifshitz gravity

Misonoh, Yosuke; Fukushima, Mitsuhiro; Miyashita, Shoichiro

doi:10.1103/physrevd.95.044044

Cited by 14 publications

(18 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our previous paper [47], we investigated the stability of the singularity-free cosmological solutions based on the projectable HL theory. Namely, we impose following the projectability condition: (1.2) where, N is the lapse function which is one of the Arnowitt-Deser-Misner (ADM) variables.…”

Section: Introductionmentioning

confidence: 99%

Stable singularity-free cosmological solutions in nonprojectable Hořava-Lifshitz gravity

et al. 2019

Self Cite

View full text Add to dashboard Cite

We find stable singularity-free cosmological solutions in non-flat Friedmann-Lemaître-Robertson-Walker (FLRW) spacetime in the context of Hořava-Lifshitz (HL) theory. Although we encounter the negative squared effective masses of the scalar perturbations in the original HL theory, the behaviors can be remedied by relaxing the projectability condition. In our analysis, the effects from the background dynamics are taken into account as well as the sign of the coefficients in the quadratic action for perturbations. More specifically, we give further classification of the gradient stability/instability into five types. These types are defined in terms of the effective squared masses of perturbations M 2 , the effective friction coefficients in perturbation equations H and these magnitude relations |M 2 |/H 2 . Furthermore, we indicate that oscillating solutions possibly show a kind of resonance especially in open FLRW spacetime. We find that the higher order spatial curvature terms with Lifshitz scaling z = 3 are significant to suppress the instabilities due to the background dynamics.PACS numbers: 98.80.Cq

show abstract

Section: Introductionmentioning

confidence: 99%

Stable singularity-free cosmological solutions in nonprojectable Hořava-Lifshitz gravity

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recent progresses have inspired a wave of looking for stable nonsingular bounce [13][14][15] (see also [16,17]), along the road beyond the cubic Galileon (even the Horndeski theory [18][19][20]). Moreover, the developments of scalar-tensor theory (the GLPV [21] and DHOST theory [22][23][24], the mimetic gravity [25,26]) might also be able to provide us with some chances to implement stable nonsingular cosmologies.…”

Section: Introductionmentioning

confidence: 99%

A covariant Lagrangian for stable nonsingular bounce

Cai

Piao

2017

J. High Energ. Phys.

100

View full text Add to dashboard Cite

Abstract:The nonsingular bounce models usually suffer from the ghost or gradient instabilities, as has been proved recently. In this paper, we propose a covariant effective theory for stable nonsingular bounce, which has the quadratic order of the second order derivative of the field φ but the background set only by P (φ, X). With it, we explicitly construct a fully stable nonsingular bounce model for the ekpyrotic scenario.

show abstract

“…We conclude that, based on EFT, not only a stable nonsingular cosmological scenario may be built without getting involved in unknown physics, but also the phenomenological possibilities of its implementation are far richer than expected (see also [52,53] for the higher spatial derivative operators). …”

Section: Resultsmentioning

confidence: 99%

The effective field theory of nonsingular cosmology: II

Cai

Qiu

et al. 2017

Eur. Phys. J. C

View full text Add to dashboard Cite

Based on the effective field theory (EFT) of cosmological perturbations, we explicitly clarify the pathology in nonsingular cubic Galileon models and show how to cure it in EFT with new insights into this issue. With the least set of EFT operators that are capable to avoid instabilities in nonsingular cosmologies, we construct a nonsingular model dubbed the Genesis-inflation model, in which a slowly expanding phase (namely, Genesis) with increasing energy density is followed by slow-roll inflation. The spectrum of the primordial perturbation may be simulated numerically, which shows itself a large-scale cutoff, as the large-scale anomalies in CMB might be a hint for.

show abstract

Stability of singularity-free cosmological solutions in Hořava-Lifshitz gravity

Cited by 14 publications

References 71 publications

Stable singularity-free cosmological solutions in nonprojectable Hořava-Lifshitz gravity

Stable singularity-free cosmological solutions in nonprojectable Hořava-Lifshitz gravity

A covariant Lagrangian for stable nonsingular bounce

The effective field theory of nonsingular cosmology: II

Contact Info

Product

Resources

About