scholarly journals Cosmological constraints from H ii starburst galaxy apparent magnitude and other cosmological measurements

2020 ◽  
Vol 497 (3) ◽  
pp. 3191-3203 ◽  
Author(s):  
Shulei Cao ◽  
Joseph Ryan ◽  
Bharat Ratra
Keyword(s):  
Dark Energy ◽  
Cosmological Parameters ◽  
Angular Size ◽  
Hubble Constant ◽  
Joint Analysis ◽  
Apparent Magnitude ◽  
Starburst Galaxy ◽  
Density Parameter ◽  
Acoustic Oscillations ◽  
Combined Data

ABSTRACT We use H ii starburst galaxy apparent magnitude measurements to constrain cosmological parameters in six cosmological models. A joint analysis of H ii galaxy, quasar angular size, baryon acoustic oscillations peak length scale, and Hubble parameter measurements result in relatively model-independent and restrictive estimates of the current values of the non-relativistic matter density parameter $\Omega _{\rm m_0}$ and the Hubble constant H0. These estimates favour a 2.0–3.4σ (depending on cosmological model) lower H0 than what is measured from the local expansion rate. The combined data are consistent with dark energy being a cosmological constant and with flat spatial hypersurfaces, but do not strongly rule out mild dark energy dynamics or slightly non-flat spatial geometries.

scholarly journals Cosmological constraints from higher redshift gamma-ray burst, H ii starburst galaxy, and quasar (and other) data

2020 ◽  
Vol 501 (1) ◽  
pp. 1520-1538
Author(s):  
Shulei Cao ◽  
Joseph Ryan ◽  
Narayan Khadka ◽  
Bharat Ratra
Keyword(s):  
Dark Energy ◽  
Gamma Ray ◽  
Angular Size ◽  
Acoustic Oscillation ◽  
Matter Density ◽  
Joint Analysis ◽  
Starburst Galaxy ◽  
Density Parameter ◽  
Gamma Ray Burst ◽  
Cosmological Constraints

ABSTRACT We use higher redshift gamma-ray burst (GRB), H ii starburst galaxy (H iiG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are mutually consistent. Cosmological constraints from a joint analysis of these data sets are largely consistent with currently accelerating cosmological expansion and with cosmological constraints derived from a combined analysis of Hubble parameter (H(z)) and baryon acoustic oscillation (BAO, with Planck-determined baryonic matter density) measurements. A joint analysis of the H(z) + BAO + QSO-AS + H iiG + GRB data provides fairly model-independent determinations of the non-relativistic matter density parameter $\Omega _{\rm m_0}=0.313\pm 0.013$ and the Hubble constant $H_0=69.3\pm 1.2\, \rm {km \, s^{-1} \, Mpc^{-1}}$. These data are consistent with the dark energy being a cosmological constant and with spatial hypersurfaces being flat, but they do not rule out mild dark energy dynamics or a little spatial curvature. We also investigate the effect of including quasar flux measurements in the mix and find no novel conclusions.

scholarly journals Using quasar X-ray and UV flux measurements to constrain cosmological model parameters

2020 ◽  
Vol 497 (1) ◽  
pp. 263-278 ◽  
Author(s):  
Narayan Khadka ◽  
Bharat Ratra
Keyword(s):  
Cosmological Parameters ◽  
Hubble Constant ◽  
Acoustic Oscillation ◽  
Joint Analysis ◽  
Model Parameters ◽  
Density Parameter ◽  
Current Standard ◽  
X Ray ◽  
Flux Measurements ◽  
Parameter Constraints

ABSTRACT Risaliti and Lusso have compiled X-ray and UV flux measurements of 1598 quasars (QSOs) in the redshift range 0.036 ≤ z ≤ 5.1003, part of which, z ∼ 2.4 − 5.1, is largely cosmologically unprobed. In this paper we use these QSO measurements, alone and in conjunction with baryon acoustic oscillation (BAO) and Hubble parameter [H(z)] measurements, to constrain cosmological parameters in six different cosmological models, each with two different Hubble constant priors. In most of these models, given the larger uncertainties, the QSO cosmological parameter constraints are mostly consistent with those from the BAO + H(z) data. A somewhat significant exception is the non-relativistic matter density parameter Ωm0 where QSO data favour Ωm0 ∼ 0.5 − 0.6 in most models. As a result, in joint analyses of QSO data with H(z) + BAO data the 1D Ωm0 distributions shift slightly towards larger values. A joint analysis of the QSO + BAO + H(z) data is consistent with the current standard model, spatially-flat ΛCDM, but mildly favours closed spatial hypersurfaces and dynamical dark energy. Since the higher Ωm0 values favoured by QSO data appear to be associated with the z ∼ 2 − 5 part of these data, and conflict somewhat with strong indications for Ωm0 ∼ 0.3 from most z < 2.5 data as well as from the cosmic microwave background anisotropy data at z ∼ 1100, in most models, the larger QSO data Ωm0 is possibly more indicative of an issue with the z ∼ 2 − 5 QSO data than of an inadequacy of the standard flat ΛCDM model.

scholarly journals The dark sector cosmology

2020 ◽  
Vol 29 (14) ◽  
pp. 2030014
Author(s):  
Elcio Abdalla ◽  
Alessandro Marins
Keyword(s):  
Dark Energy ◽  
Cosmological Parameters ◽  
Hubble Constant ◽  
Acoustic Oscillations ◽  
Dark Sector ◽  
Fundamental Physics ◽  
Observational Techniques ◽  
Distance Indicators ◽  
The Universe ◽  
Theoretical Developments

The most important problem in fundamental physics is the description of the contents of the Universe. Today, we know that 95% thereof is totally unknown. Two thirds of that amount is the mysterious Dark Energy described in an interesting and important review [E. J. Copeland, M. Sami and S. Tsujikawa, Int. J. Mod. Phys. D 15 (2006) 1753]. We briefly extend here the ideas contained in that review including the more general Dark Sector, that is, Dark Matter and Dark Energy, eventually composing a new physical Sector. Understanding the Dark Sector with precision is paramount for us to be able to understand all the other cosmological parameters comprehensively as modifications of the modeling could lead to potential biases of inferred parameters of the model, such as measurements of the Hubble constant and distance indicators such as the Baryon Acoustic Oscillations. We discuss several modern methods of observation that can disentangle the different possible descriptions of the Dark Sector. The possible applications of some theoretical developments are also included in this paper as well as a more thorough evaluation of new observational techniques at lower frequencies and gravitational waves.

scholarly journals Measurements of $$H_0$$ and reconstruction of the dark energy properties from a model-independent joint analysis

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Alexander Bonilla ◽  
Suresh Kumar ◽  
Rafael C. Nunes
Keyword(s):  
Dark Energy ◽  
Sound Speed ◽  
Hubble Constant ◽  
State Parameter ◽  
Independent Method ◽  
Joint Analysis ◽  
Acoustic Oscillations ◽  
Type Ia ◽  
Model Independent ◽  
Supernova Type Ia

AbstractGaussian processes (GP) provide an elegant and model-independent method for extracting cosmological information from the observational data. In this work, we employ GP to perform a joint analysis by using the geometrical cosmological probes such as Supernova Type Ia (SN), Cosmic chronometers (CC), Baryon Acoustic Oscillations (BAO), and the H0LiCOW lenses sample to constrain the Hubble constant $$H_0$$ H 0 , and reconstruct some properties of dark energy (DE), viz., the equation of state parameter w, the sound speed of DE perturbations $$c^2_s$$ c s 2 , and the ratio of DE density evolution $$X = \rho _\mathrm{de}/\rho _\mathrm{de,0}$$ X = ρ de / ρ de , 0 . From the joint analysis SN+CC+BAO+H0LiCOW, we find that $$H_0$$ H 0 is constrained at 1.1% precision with $$H_0 = 73.78 \pm 0.84\ \hbox {km}\ \hbox {s}^{-1}\,\hbox {Mpc}^{-1}$$ H 0 = 73.78 ± 0.84 km s - 1 Mpc - 1 , which is in agreement with SH0ES and H0LiCOW estimates, but in $$\sim 6.2 \sigma $$ ∼ 6.2 σ tension with the current CMB measurements of $$H_0$$ H 0 . With regard to the DE parameters, we find $$c^2_s < 0$$ c s 2 < 0 at $$\sim 2 \sigma $$ ∼ 2 σ at high z, and the possibility of X to become negative for $$z > 1.5$$ z > 1.5 . We compare our results with the ones obtained in the literature, and discuss the consequences of our main results on the DE theoretical framework.

scholarly journals H0LiCOW – XIII. A 2.4 per cent measurement of H0 from lensed quasars: 5.3σ tension between early- and late-Universe probes

2019 ◽  
Vol 498 (1) ◽  
pp. 1420-1439 ◽  
Author(s):  
Kenneth C Wong ◽  
Sherry H Suyu ◽  
Geoff C-F Chen ◽  
Cristian E Rusu ◽  
Martin Millon ◽  
...  
Keyword(s):  
Time Delay ◽  
Cold Dark Matter ◽  
Cosmological Parameters ◽  
Hubble Constant ◽  
Joint Analysis ◽  
Type Ia Supernovae ◽  
Acoustic Oscillations ◽  
Type Ia ◽  
Measured Time ◽  
Ia Supernovae

ABSTRACT We present a measurement of the Hubble constant (H0) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analysed blindly with respect to the cosmological parameters. In a flat Λ cold dark matter (ΛCDM) cosmology, we find $H_{0} = 73.3_{-1.8}^{+1.7}~\mathrm{km~s^{-1}~Mpc^{-1}}$, a $2.4{{\ \rm per\ cent}}$ precision measurement, in agreement with local measurements of H0 from type Ia supernovae calibrated by the distance ladder, but in 3.1σ tension with Planck observations of the cosmic microwave background (CMB). This method is completely independent of both the supernovae and CMB analyses. A combination of time-delay cosmography and the distance ladder results is in 5.3σ tension with Planck CMB determinations of H0 in flat ΛCDM. We compute Bayes factors to verify that all lenses give statistically consistent results, showing that we are not underestimating our uncertainties and are able to control our systematics. We explore extensions to flat ΛCDM using constraints from time-delay cosmography alone, as well as combinations with other cosmological probes, including CMB observations from Planck, baryon acoustic oscillations, and type Ia supernovae. Time-delay cosmography improves the precision of the other probes, demonstrating the strong complementarity. Allowing for spatial curvature does not resolve the tension with Planck. Using the distance constraints from time-delay cosmography to anchor the type Ia supernova distance scale, we reduce the sensitivity of our H0 inference to cosmological model assumptions. For six different cosmological models, our combined inference on H0 ranges from ∼73 to 78 km s−1 Mpc−1, which is consistent with the local distance ladder constraints.

scholarly journals Cosmological Parameter Survey Using the Gravitational Lensing Method

2001 ◽  
Vol 18 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Premana W. Premadi ◽  
Hugo Martel ◽  
Richard Matzner ◽  
Toshifumi Futamase
Keyword(s):  
Gravitational Lensing ◽  
Light Propagation ◽  
Cold Dark Matter ◽  
Cosmological Parameters ◽  
Angular Size ◽  
Hubble Constant ◽  
Density Parameter ◽  
Multiple Imaging ◽  
Light Rays ◽  
Insight Into

AbstractUsing a multiple-lens plane algorithm, we study light propagation in inhomogeneous universes for 43 different COBE-normalized Cold Dark Matter models, with various values of the density parameter Ω0, cosmological constant λ0, Hubble constant H0, and rms density fluctuation σ8.We performed a total of 3798 experiments, each experiment consisting of propagating a square beam of angular size 21.9″ 21.9″ composed of 116 281 light rays from the observer up to redshift z = 3. These experiments provide statistics of the magnification, shear, and multiple imaging of distant sources. The results of these experiments might be compared with observations, and eventually help constrain the possible values of the cosmological parameters. Additionally, they provide insight into the gravitational lensing process and its complex relationship with the various cosmological parameters.

scholarly journals Bayesian comparison of interacting modified holographic Ricci dark energy scenarios

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Antonella Cid ◽  
Carlos Rodriguez-Benites ◽  
Mauricio Cataldo ◽  
Gonzalo Casanova
Keyword(s):  
Dark Energy ◽  
Hubble Constant ◽  
Joint Analysis ◽  
Acoustic Oscillations ◽  
Microwave Background ◽  
Ricci Dark Energy ◽  
Type Ia ◽  
Cosmological Data ◽  
Ia Supernovae ◽  
Local Value

AbstractWe perform a Bayesian model selection analysis for interacting scenarios of dark matter and modified holographic Ricci dark energy (MHRDE) with linear interacting terms. We use a combination of some of the latest cosmological data such as type Ia supernovae, cosmic chronometers, the local value of the Hubble constant, baryon acoustic oscillations measurements and cosmic microwave background through the angular scale of the sound horizon at last scattering. We find moderate/strong evidence against all the MHRDE interacting scenarios studied with respect to $$\Lambda $$ Λ CDM when the full joint analysis is considered.

scholarly journals ΛCDM periodic cosmology

2020 ◽  
Vol 494 (2) ◽  
pp. 2183-2190
Author(s):  
Stéphane Fay
Keyword(s):  
Dark Energy ◽  
Cold Dark Matter ◽  
Accelerated Expansion ◽  
Density Parameter ◽  
Acoustic Oscillations ◽  
Microwave Background ◽  
Hubble Expansion ◽  
Background Data ◽  
Periodic Models ◽  
Cosmic Microwave Background Data

ABSTRACT We examine the possibility that Universe expansion be made of some Λ-cold dark matter (ΛCDM) expansions repeating periodically, separated by some inflation- and radiation-dominated phases. This so-called ΛCDM periodic cosmology is motivated by the possibility that inflation and the present phase of accelerated expansion be due to the same dark energy. Then, in a phase space showing the variation of matter density parameter Ωm with respect to this of the radiation Ωr, the curve Ωm(Ωr) looks like a closed trajectory that Universe could run through forever. In this case, the end of the expansion acceleration of the ΛCDM phase is the beginning of a new inflation phase. We show that such a scenario implies the coupling of matter and/or radiation to dark energy. We consider the simplest of these ΛCDM periodic models i.e. a vacuum energy coupled to radiation. From matter domination phase to today, it behaves like a ΛCDM model, then followed by an inflation phase. But a sudden and fast decay of the dark energy into radiation periodically ends the expansion acceleration. This leads to a radiation-dominated Universe preceding a new ΛCDM type expansion. The model is constrained with Markov Chain Monte Carlo simulations using supernovae, Hubble expansion, Baryon Acoustic Oscillations (BAO), and cosmic microwave background data and fits the data as well as the ΛCDM one.

MASS INHOMOGENEITIES AND THE ANGULAR SIZE-REDSHIFT RELATION

2004 ◽  
Vol 13 (07) ◽  
pp. 1309-1313 ◽  
Author(s):  
JAILSON S. ALCANIZ ◽  
JOSÉ A. S. LIMA ◽  
RAIMUNDO SILVA
Keyword(s):  
Dark Energy ◽  
Angular Size ◽  
Matter Density ◽  
Radio Sources ◽  
Density Parameter ◽  
Energy Component ◽  
Dark Energy Component ◽  
Smoothness Parameter ◽  
Best Fit ◽  
Size Data

We investigate the influence of mass inhomogeneities on the angular size-redshift test through a statistical analysis of angular size data for a large sample of milliarcsecond radio sources. The results are based on flat models driven by nonrelativistic matter plus a dark energy component in the form of a relic cosmological constant. To model the mass inhomogeneities we use the Zeldovich–Kantowski distance formula (also known as Dyer–Roeder distance redshift relation) which is characterized by the smoothness parameter α. Marginalizing over the characteristic angular size l and assuming a Gaussian prior on the matter density parameter, i.e., Ωm=0.35±0.07, the best fit model occurs at Ωm=0.35 and α=0.8. For an analysis without priors and minimizing χ2 for the parameters l, Ωm and α we find that a conventional homogeneous scenario (α=1) with Ωm=0.2 and D=22.6h-1 pc constitutes the best fit model for the present angular size data.

scholarly journals Studying Type II supernovae as cosmological standard candles using the Dark Energy Survey

2020 ◽  
Vol 495 (4) ◽  
pp. 4860-4892 ◽  
Author(s):  
T de Jaeger ◽  
L Galbany ◽  
S González-Gaitán ◽  
R Kessler ◽  
A V Filippenko ◽  
...  
Keyword(s):  
Dark Energy ◽  
High Redshift ◽  
Cosmological Parameters ◽  
Hubble Constant ◽  
Distance Modulus ◽  
Type Ii ◽  
Hubble Diagram ◽  
Dark Energy Survey ◽  
Spectroscopic Information ◽  
Energy Survey

ABSTRACT Despite vast improvements in the measurement of the cosmological parameters, the nature of dark energy and an accurate value of the Hubble constant (H0) in the Hubble–Lemaître law remain unknown. To break the current impasse, it is necessary to develop as many independent techniques as possible, such as the use of Type II supernovae (SNe II). The goal of this paper is to demonstrate the utility of SNe II for deriving accurate extragalactic distances, which will be an asset for the next generation of telescopes where more-distant SNe II will be discovered. More specifically, we present a sample from the Dark Energy Survey Supernova Program (DES-SN) consisting of 15 SNe II with photometric and spectroscopic information spanning a redshift range up to 0.35. Combining our DES SNe with publicly available samples, and using the standard candle method (SCM), we construct the largest available Hubble diagram with SNe II in the Hubble flow (70 SNe II) and find an observed dispersion of 0.27 mag. We demonstrate that adding a colour term to the SN II standardization does not reduce the scatter in the Hubble diagram. Although SNe II are viable as distance indicators, this work points out important issues for improving their utility as independent extragalactic beacons: find new correlations, define a more standard subclass of SNe II, construct new SN II templates, and dedicate more observing time to high-redshift SNe II. Finally, for the first time, we perform simulations to estimate the redshift-dependent distance-modulus bias due to selection effects.

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