Fractional dark energy: Phantom behavior and negative absolute temperature

Landim, Ricardo G.

doi:10.1103/physrevd.104.103508

Cited by 6 publications

(2 citation statements)

References 116 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is worth mentioning that fractional calculus has also been employed to modify the Friedmann and Raychaudhuri equations, thereby enabling an investigation into the dynamics of the universe without the need for cold dark matter (CDM) or dark energy [77]. In addition, an alternative approach involves the utilization of fractional calculus to determine the value of the cosmological constant, which necessitates a restructuring due to the well-recognized ultraviolet divergence in conventional quantum field theory [78][79][80]. To expand the scope of this fractional approach, [81,82] explore modified Newtonian dynamics (MOND) and quantum cosmology.…”

Section: Introductionmentioning

confidence: 99%

Estimated Age of the Universe in Fractional Cosmology

Costa,

Jalalzadeh,

da Silva Júnior

et al. 2023

Fractal Fract

View full text Add to dashboard Cite

Our proposed cosmological framework, which is based on fractional quantum cosmology, aims to address the issue of synchronicity in the age of the universe. To achieve this, we have developed a new fractional ΛCDM cosmological model. We obtained the necessary formalism by obtaining the fractional Hamiltonian constraint in a general minisuperspace. This formalism has allowed us to derive the fractional Friedmann and Raychaudhuri equations for a homogeneous and isotropic cosmology. Unlike the traditional de Sitter phase, our model exhibits a power-law accelerated expansion in the late-time universe, when vacuum energy becomes dominant. By fitting the model’s parameters to cosmological observations, we determined that the fractional parameter of Lévy equals α=1.986. Additionally, we have calculated the age of the universe to be 13.8196 Gyr. Furthermore, we have found that the ratio of the age to Hubble time from the present epoch to the distant future is finite and confined within the interval 0.9858≤Ht<95.238.

show abstract

Section: Introductionmentioning

confidence: 99%

Estimated Age of the Universe in Fractional Cosmology

Costa,

Jalalzadeh,

da Silva Júnior

et al. 2023

Fractal Fract

View full text Add to dashboard Cite

show abstract

“…The lack of understating about the nature of the cosmological constant and the aforementioned issues encourage alternative models of DE. Among the many candidates there are scalar and vector fields [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], metastable DE [29][30][31][32][33][34][35][36][37], models using extra dimensions [38], alternative fluids [39,40], etc. Another explanation for DE comes from the holographic principle, the so-called holographic DE (HDE) [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]…”

Section: Introductionmentioning

confidence: 99%

A note on interacting holographic dark energy with a Hubble-scale cutoff

Landim

2022

Preprint

Self Cite

View full text Add to dashboard Cite

Holographic dark energy with the Hubble radius as infrared cutoff has been considered as a candidate to explain the late-time cosmic acceleration and it can solve the coincidence problem. In this scenario, a non-zero equation of state is only possible if there is an interaction between dark energy and cold dark matter. In this paper, a set of phenomenological interactions are assumed and a detailed analysis of the possible values of the coupling constants is carried out, however the resulting matter power spectrum and cosmic microwave background temperature and polarization power spectra have a shape very far from the observed ones. These results rule out any value for the free parameters and it seems to indicate that the assumed interacting holographic dark energy with a Hubble-scale cutoff is not viable to explain the accelerated expansion of the Universe, when cosmological data are taken into account.

show abstract

Note on interacting holographic dark energy with a Hubble-scale cutoff

Landim¹

2022

Phys. Rev. D

View full text Add to dashboard Cite

Fractional dark energy: Phantom behavior and negative absolute temperature

Cited by 6 publications

References 116 publications

Estimated Age of the Universe in Fractional Cosmology

Estimated Age of the Universe in Fractional Cosmology

A note on interacting holographic dark energy with a Hubble-scale cutoff

Note on interacting holographic dark energy with a Hubble-scale cutoff

Contact Info

Product

Resources

About