Constraining the dark energy models with 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>H</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>z</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math>
 data: An approach independent of 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>H</mml:mi><mml:mn>0</mml:mn></mml:msub></mml:math>

Anagnostopoulos, Fotios K.; Basilakos, Spyros

doi:10.1103/physrevd.97.063503

Cited by 36 publications

(28 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We carried out a standard likelihood analysis with up to three different free parameters: Ω m , λ and the equation of state w. We always assume uniform priors on λ and w. For the matter density we will in some cases use a Plancklike prior, Ω m = 0.315 ± 0.007 [11], otherwise the prior is also uniform. Another relevant parameter is the Hubble constant, but this is always analytically marginalized in our analysis, following the procedure detailed in [12].…”

Section: Constraints From Current Datamentioning

confidence: 99%

Low-redshift constraints on homogeneous and isotropic universes with torsion

Marques

Martins

2020

Physics of the Dark Universe

View full text Add to dashboard Cite

One of the possible extensions of Einstein's General Theory of Relativity consists in allowing for the presence of spacetime torsion. The form of the underlying torsion tensor can be chosen such that the homogeneity and isotropy of Friedmann-Lemaitre-Robertson-Walker universes is preserved, and it has been recently suggested that such universes may undergo accelerating phases. We use recent low-redshift data, coming from Type Ia Supernova and Hubble parameter measurements, to phenomenologically constrain this class of models under the so-called steady-state torsion assumption of a constant fractional contribution of torsion to the volume expansion. We start by considering models without a cosmological constant (where torsion itself would be expected to yield the current acceleration of the universe) finding, in agreement with other recent works, that these are strongly disfavoured by the data. We then treat these models as one-parameter extensions of ΛCDM, constraining the relative contribution of torsion to the level of a few percent in appropriate units. Finally, we briefly discuss how these constraints may be improved by forthcoming low-redshift data and check the robustness of our results by studying an alternative to the steady-state torsion parametrization.

show abstract

Section: Constraints From Current Datamentioning

confidence: 99%

Low-redshift constraints on homogeneous and isotropic universes with torsion

Marques

Martins

2020

Physics of the Dark Universe

View full text Add to dashboard Cite

show abstract

“…8, we show the deviation of the observable Hub-ble expansion rate for various values of Ω m (left panel) and of w (right panel) along with corresponding data obtained from the spectroscopic evolution of galaxies used as cosmic chronometers, shown in Table IV in the Appendix along with the corresponding citations (for previous compilations see also Refs. [64][65][66]). Even though Figs.…”

Section: Growth Of Density Perturbationsmentioning

confidence: 99%

Constraining power of cosmological observables: Blind redshift spots and optimal ranges

2019

View full text Add to dashboard Cite

2 − 3σ) is the Ω m − σ 8 tension between the CMB Planck data and the growth of density perturbations data (RSD and WL) [5][6][7][8][9]. The CMB data favor higher values of the matter density parameter Ω m and the matter fluctuations amplitude σ 8 than the data that probe directly the gravitational interaction (RSD and WL).A key question therefore arises: Are these tensions an early hint of new physics beyond the standard model or are they a result of systematic/statistical fluctuations in the data?Completed, ongoing and future CMB experiments and large scale structure surveys aim at testing the standard ΛCDM model and addressing the above question. These surveys are classified in four stages. Stages I and II correspond to completed surveys and CMB experiments, while stages III and IV correspond to ongoing and future projects respectively. For example stage II CMB experiments include WMAP [10], Planck [2, 3], ACTPol [11] and SPT-Pol [12], while stage III CMB experiments include AdvACT [13] and SPT-3G [14]. Future stage IV CMB probes on the ground[15] and in space such as Lite-BIRD [16, 17] mainly aim to measure CMB lensing and the CMB-B modes in detail.A large amount of high-quality data is expected in the coming years from large scale structure surveys (see Table I). Stage III large scale structure surveys include the Canada-France-Hawaii Telescope Lensing Survey [18], the Kilo Degree Survey (KiDS) [8,9], the extended arXiv:1812.05356v2 [astro-ph.CO]

show abstract

“…Specifically, the Hubble parameter measurements reach up to redshift z ∼ 2.36, while the supernova data is at z < 1.5 and the α measurements reach z ∼ 4. The Hubble constant is always analytically marginalized, following the prescription of [15].…”

Section: A Background Cosmologymentioning

confidence: 99%

Astrophysical and local constraints on string theory: Runaway dilaton models

Martins

Vacher

2019

Phys. Rev. D

View full text Add to dashboard Cite

One of the clear predictions of string theory is the presence of a dynamical scalar partner of the spin-2 graviton, known as the dilaton. This will violate the Einstein Equivalence Principle, leading to a plethora of possibly observable consequences which is a cosmological context include dynamical dark energy and spacetime variations of nature's fundamental constants. The runaway dilaton scenario of Damour, Piazza and Veneziano is a particularly interesting class of string theory inspired models which can in principle reconcile a massless dilaton with experimental data. Here we use the latest background cosmology observations, astrophysical and laboratory tests of the stability of the fine-structure constant and local tests of the Weak Equivalence Principle to provide updated constraints on this scenario, under various simplifying assumptions. Overall we find consistency with the standard ΛCDM paradigm, and we improve the existing constraints on the coupling of the dilaton to baryonic matter by a factor of six, and to the dark sector by a factor of two. At the one sigma level the current data already excludes dark sector couplings of order unity, which would be their natural value.

show abstract

Constraining the dark energy models with H(z) data: An approach independent of H0

Cited by 36 publications

References 64 publications

Low-redshift constraints on homogeneous and isotropic universes with torsion

Low-redshift constraints on homogeneous and isotropic universes with torsion

Constraining power of cosmological observables: Blind redshift spots and optimal ranges

Astrophysical and local constraints on string theory: Runaway dilaton models

Contact Info

Product

Resources

About