Recent discussions about supernova magnitude evolution have raised doubts about the robustness of the late-universe acceleration. In a previous letter, Huang did a null test of the cosmic acceleration by using a Parameterization based on the cosmic Age (PAge), which covers a broad class of cosmological models including the standard $Λ$ cold dark matter model and its many extensions. In this work, we continue to explore the cosmic expansion history with the PAge approximation. Using baryon acoustic oscillations ({\it without} a CMB prior on the acoustic scale), gravitational strong lens time delay, and passively evolving early galaxies as cosmic chronometers, we obtain $\gtrsim 4σ$ detections of cosmic acceleration for both flat and nonflat PAge universes. In the nonflat case, we find a $\gtrsim 3σ$ tension between the spatial curvatures derived from baryon acoustic oscillations and strong lens time delay. Implications and possible systematics are discussed.
Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only the spatially homogeneous part of the cosmological model, such as Type Ia supernova apparent magnitude, baryon acoustic oscillation distance, and Hubble parameter measurements, can be used in conjunction with the CMB data to more tightly constrain parameters. Recent joint analyses of CMB and such non-CMB data indicate that slightly closed spatial hypersurface…
We consider recently proposed higher order gravity models where the action is built from the Einstein-Hilbert action plus a function f(G) of the Gauss-Bonnet invariant. The models were previously shown to pass physical acceptability conditions as well as solar system tests. In this paper, we compare the models to combined data sets of supernovae, baryon acoustic oscillations, and constraints from the CMB surface of last scattering. We find that the models provide fits to the data that are close to those of the LCDM concordance model. The results provide a pool of higher order gravity models th…
Delta Gravity is a gravitational model based on an extension of General Relativity given by a new symmetry called $\tildeδ$. In this model, new matter fields are added to the original matter fields, motivated by the additional symmetry. We call them $\tildeδ$ matter fields. This model predicts an accelerating Universe without the need to introduce a cosmological constant. In this work, we study the Delta Gravity prediction about the scalar CMB TT power spectrum using an analytical hydrodynamical approach. To fit the Planck satellite's data with the DG model, we used a Markov Chain Monte Carlo …
In this Letter, by reconstructing the $Om$ diagnostic and the deceleration parameter $q$ from the latest Union2 Type Ia supernova sample with and without the systematic error along with the baryon acoustic oscillation (BAO) and the cosmic microwave background (CMB), we study the cosmic expanding history, using the Chevallier-Polarski-Linder (CPL) parametrization. We obtain that Union2+BAO favor an expansion with a decreasing of the acceleration at $z<0.3$. However, once the CMB data is added in the analysis, the cosmic acceleration is found to be still increasing, indicating a tension between …
Many theoretical resolutions to the so-called "Hubble tension" rely on modifying the sound horizon at recombination, $r_s$, and thus the acoustic scale used as a standard ruler in the cosmic microwave background (CMB) and large scale structure (LSS) datasets. As shown in a number of recent works, these observables can also be used to compute $r_s$-independent constraints on $H_0$ by making use of the horizon scale at matter-radiation equality, $k_{\rm eq}$, which has different sensitivity to high redshift physics than $r_s$. As such, $r_s$- and $k_{\rm eq}$-based measurements of $H_0$ (within …
We investigate a scalar field dark energy model (i.e., $ϕ$CDM model) with massive neutrinos, where the scalar field possesses an inverse power-law potential, i.e., $V(ϕ)\propto ϕ^{-α}$ ($α>0$). We find that the sum of neutrino masses $Σm_ν$ has significant impacts on the CMB temperature power spectrum and on the matter power spectrum. In addition, the parameter $α$ also has slight impacts on the spectra. A joint sample, including CMB data from Planck 2013 and WMAP9, galaxy clustering data from WiggleZ and BOSS DR11, and JLA compilation of Type Ia supernova observations, is adopted to confine t…
The dimming of Type Ia supernovae could be the result of Hubble-scale inhomogeneity in the matter and spatial curvature, rather than signaling the presence of a dark energy component. A key challenge for such models is to fit the detailed spectrum of the cosmic microwave background (CMB). We present a detailed discussion of the small-scale CMB in an inhomogeneous universe, focusing on spherically symmetric `void' models. We allow for the dynamical effects of radiation while analyzing the problem, in contrast to other work which inadvertently fine tunes its spatial profile. This is a surprising…
In this paper we study cosmological signatures of modified gravity theories that can be written as a coupling between a extra scalar field and the electromagnetic part of the usual Lagrangian for the matter fields. In these frameworks all the electromagnetic sector of the theory is affected and variations of fundamental constants, of the cosmic distance duality relation and of the evolution law of the cosmic microwave background radiation (CMB) are expected and are related each other. In order to search these variations we perform jointly analyses with angular diameter distances of galaxy clus…
Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol significantly complement cosmological constraints from the Planck satellite, strengthening the CMB dark energy figure of merit and neutrino mass constraints by factors of 3-4. This changes the dark energy probe landscape. We evaluate the state of knowledge in 2017 from ongoing experiments including dark energy surveys (supernovae, weak lensing, galaxy clusteri…
In the late 1990's, observations of 93 Type Ia supernovae were analysed in the framework of the FLRW cosmology assuming these to be `standard(isable) candles'. It was thus inferred that the Hubble expansion rate is accelerating as if driven by a positive Cosmological Constant $Λ$. This is still the only direct evidence for the `dark energy' that is the dominant component of the standard $Λ$CDM cosmological model. Other data such as BAO, CMB anisotropies, stellar ages, the rate of structure growth, etc are all `concordant' with this model but do not provide independent evidence for accelerated …
Joint Curvature and Growth Rate measurements with Supernova Peculiar Velocities and the CMB
Universidade Federal do Espírito Santo（埃斯皮里托圣托联邦大学）；Aix Marseille Université, CNRS/IN2P3, CPPM（艾克斯-马赛大学）；Centro Brasileiro de Pesquisas Físicas（巴西物理研究中心）；Observatório do Valongo, Universidade Federal do Rio de Janeiro（瓦隆戈天文台，里约热内卢联邦大学）；University of Arizona（亚利桑那大学）
We investigate the $H_0$ tension in a range of extended model frameworks beyond the standard $Λ$CDM without the data from cosmic microwave background (CMB). Specifically, we adopt the data from baryon acoustic oscillation, big bang nucleosynthesis and type Ia supernovae as indirect measurements of $H_0$ to study the tension. We show that the estimated value of $H_0$ from indirect measurements is overall lower than that from direct local ones regardless of the data sets and a range of extended models to be analyzed, which indicates that, although the significance of the tension varies depending…
We determine the proper motion of the Solar system from the Pantheon sample of supernovae (SNe) of type Ia. The posterior distribution of the Solar system proper velocity, its direction and relevant cosmological parameters are obtained based on the observed distance moduli, heliocentric redshifts, and positions of SNe by means of a Markov Chain Monte Carlo method. We account for the unknown peculiar motion of SNe by including their expected covariance from linear theory. We find that the Solar system moves with $v_o = 249 \pm 51$ km/s towards $RA = 166 \pm 16$ deg, $Dec = 10 \pm 19$ deg (J2000…
We revisit the kink-like parametrization of the deceleration parameter q(z), which considers a transition, at $z_t$, from cosmic deceleration to acceleration. In this parametrization the initial, at $z \gg z_t$, value of the q-parameter is $q_i$, its final, z=-1, value is $q_f$ and the duration of the transition is parametrized by $τ$. By assuming a flat space geometry we obtain constraints on the free parameters of the model using recent data from type Ia supernovae, BAO, CMB and the Hubble parameter H(z). The use of H(z) data introduces an explicit dependence of the combined likelihood on th…
Probing Physics Beyond the Standard Model through Combined Analyses of Next-Generation Type Ia Supernova, CMB, and BAO Surveys
National Center for Supercomputing Applications（国家超级计算应用中心）；Duke University（杜克大学）；California Institute of Technology（加州理工学院）；SLAC National Accelerator Laboratory（SLAC国家加速器实验室）；Université Clermont Auvergne（克莱蒙奥弗涅大学）；Institut de Física d’Altes Energies (IFAE)（高能物理研究所）
Measurements of the Hubble constant, $H_0$, from the cosmic distance ladder are currently in tension with the value inferred from Planck observations of the CMB and other high redshift datasets if a flat $Λ$CDM cosmological model is assumed. One of the few promising theoretical resolutions of this tension is to invoke new physics that changes the sound horizon scale in the early universe; this can bring CMB and BAO constraints on $H_0$ into better agreement with local measurements. In this paper, we discuss how a measurement of the Hubble constant can be made from the CMB without using informa…
The cosmic spatial curvature parameter $Ω_k$ is constrained, primarily by cosmic microwave background (CMB) data, to be very small. Observations of the cosmic distance ladder and the large scale structure can provide independent checks of the cosmic flatness. Such late-universe constraints on $Ω_k$, however, are sensitive to the assumptions of the nature of dark energy. For minimally coupled scalar-field models of dark energy, the equation of state $w$ has nontrivial dependence on the cosmic spatial curvature $Ω_k$ (Miao and Huang, 2018). Such dependence has not been taken into account in prev…
It is well known that observations of the cosmic microwave background (CMB) are highly sensitive to the spatial curvature of the Universe, k. Here we find that what is in fact being tightly constrained by small angle fluctuations is spatial curvature near the surface of last scattering, and that if we allow k to be a function of position, rather than taking a constant value everywhere, then considerable spatial curvature is permissible within our own locale. This result is of interest for the giant void models that attempt to explain the supernovae observations without Dark Energy. We find voi…
We have shown (Colin et al., 2019) that the acceleration of the Hubble expansion rate inferred from Type Ia supernovae (SNe Ia) is, at $3.9σ$ significance, a dipole approximately aligned with the CMB dipole, while its monopole component, which can be interpreted as due to a Cosmological Constant or dark energy, is consistent with zero at $1.4σ$. This has been challenged by Rubin & Heitlauf (2019) who assert that the dipole arises because we made an incorrect assumption about the SNe Ia light-curve parameters (viz. took them to be sample- and redshift independent), and did not allow for the mot…
Can cosmic rotation resolve the Hubble tension? Constraints from CMB and large-scale structure
Scuola Superiore Meridionale（南方高等学院）；Istituto Nazionale di Fisica Nucleare, sez. di Napoli（意大利国家核物理研究所那不勒斯分部）；Instituto de Física, Universidade Federal da Bahia（巴伊亚联邦大学物理研究所）；Observatório Nacional（国家天文台）
We have succeeded in establishing a cosmological model with a non-minimally coupled scalar field $ϕ$ that can account not only for the spatial periodicity or the {\it picket-fence structure} exhibited by the galaxy $N$-$z$ relation of the 2dF survey but also for the spatial power spectrum of the cosmic microwave background radiation (CMB) temperature anisotropy observed by the WMAP satellite. The Hubble diagram of our model also compares well with the observation of Type Ia supernovae. The scalar field of our model universe starts from an extremely small value at around the nucleosynthesis epo…
The idea of a negative-pressure dark energy component in the Universe which causes an accelerated expansion in the late Universe has deep implications in models of field theory and general relativity. In this article, we survey the evidence for dark energy from cosmological observations which started from the compilation of distance-luminosity plots of Type Ia supernovae. This turned out to be consistent with the dark energy inferred from the CMB observations and large scale surveys and gave rise to the concordance $Λ$CDM model of cosmology. In this article, we discuss the observational eviden…
The mismatch between the locally measured expansion rate of the universe and the one inferred from observations of the cosmic microwave background (CMB) assuming the canonical $Λ$CDM model has become the new cornerstone of modern cosmology, and many new-physics set ups are rising to the challenge. Concomitant with the so-called $H_0$ problem, there is evidence of a growing tension between the CMB-preferred value and the local determination of the weighted amplitude of matter fluctuations $S_8$. It would be appealing and compelling if both the $H_0$ and $S_8$ tensions were resolved at once, but…
The recent $\sim 4 \, σ$ Hubble constant, $H_{0}$, tension is observed between the value of $H_{0}$ from the Cosmic Microwave Background (CMB) and Type Ia Supernovae (SNe Ia). It is a decade since this tension is excruciating the modern astrophysical community. To shed light on this problem is key to consider probes at intermediate redshifts between SNe Ia and CMB and reduce the uncertainty on $H_0$. Toward these goals, we fill the redshift gap by employing Gamma-Ray Bursts (GRBs) and Quasars (QSOs), reaching $z=9.4$ and $z=7.6$, respectively, combined with Baryonic Acoustic Oscillations (BAO)…
The $Λ$CDM model is the current standard model in cosmology thanks to its ability to reproduce the observations. Its first observational evidence appeared from the type Ia supernovae (SNIa) Hubble diagram. However, there has been some debate in the literature concerning the statistical treatment of SNIa. In this paper we relax the standard assumption that SNIa intrinsic luminosity is independent of the redshift, and we examine whether it may have an impact on the accelerated nature of the expansion of the Universe. In order to be as general as possible, we reconstruct the expansion rate of the…
To explore whether there is new physics going beyond the standard cosmological model or not, we constrain seven cosmological models by combining the latest and largest Pantheon Type Ia supernovae sample with the data combination of baryonic acoustic oscillations, cosmic microwave background radiation, Planck lensing and cosmic chronometers. We find that a spatially flat universe is preferred in the framework of $Λ$CDM cosmology, that the constrained equation of state of dark energy is very consistent with the cosmological constant hypothesis, that there is no evidence of dynamical dark energy,…
Nowadays, thanks to the improved precision of cosmological data, it has been possible to search for deviation from the general relativity theory with tests on large cosmic scales. Particularly, there is a class of modified gravity theories that breaks the Einstein equivalence principle (EEP) in the electromagnetic sector, generating variations of the fine structure constant, violations of the cosmic distance duality relation and the evolution law of the cosmic microwave background (CMB) radiation. In recent papers, this class of theories has been tested with angular diameter distances from gal…
Updated Cosmological Constraints in Extended Parameter Space with Planck PR4, DESI Baryon Acoustic Oscillations, and Supernovae: Dynamical Dark Energy, Neutrino Masses, Lensing Anomaly, and the Hubble Tension
本文在12参数扩展宇宙学模型中结合 Planck PR4、DESI BAO 和超新星数据更新了约束，发现暗能量动力学性质不稳健，中微子质量上限为0.3 eV，透镜异常不显著，哈勃张力未解决，$S_8$ 张力有所降低。
We investigate the cosmic thermal evolution with a vacuum energy which decays into photon at the low-redshift. We assume that the vacuum energy is a function of the scale factor that increases toward the early universe. We put on the constraints using recent observations of both type Ia supernovae (SNIa) by Union-2 compilation and the cosmic microwave background (CMB) temperature at the range of the redshift 0.01 < z < 3. From SNIa, we find that the effects of a decaying vacuum energy on the cosmic expansion rate should be very small but could be possible for z < 1.5. On the other hand, we obt…
We present a measurement of the Hubble constant ($H_{0}$) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analyzed blindly with respect to the cosmological parameters. In a flat $Λ$CDM cosmology, we find $H_{0} = 73.3_{-1.8}^{+1.7}$, a 2.4% precision measurement, in agreement with local measurements of $H_{0}$ 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 indepen…
Recent local measurements of the Hubble constant made using supernovae have delivered a value that differs by $\sim$5$σ$ (statistical error) from predictions using the Cosmic Microwave Background (CMB), or using Baryon Acoustic Oscillations (BAO) and Big-Bang Nucleosynthesis (BBN) constraints, which are themselves consistent. The effective volume covered by the supernovae is small compared to the other probes, and it is therefore interesting to consider whether sample variance (often also called cosmic variance) is a significant contributor to the offset. We consider four ways of calculating t…
We present limits on the parameters of the o$Λ$CDM, $w_0$CDM, and $w_0 w_a$CDM models obtained from the joint analysis of the full-shape, baryon acoustic oscillations (BAO), big bang nucleosynthesis (BBN) and supernovae data. Our limits are fully independent of the data on the cosmic microwave background (CMB) anisotropies, but rival the CMB constraints in terms of parameter error bars. We find the spatial curvature consistent with a flat universe $Ω_k=-0.043_{-0.036}^{+0.036}$ ($68\%$ C.L.); the dark-energy equation of state parameter $w_0$ is measured to be $w_0=-1.031_{-0.048}^{+0.052}$ ($6…
The Hubble Constant measured from the anisotropy in the cosmic microwave background (CMB) is shown to be independent of small changes from the standard model of the redshift dependence of dark energy. Modifications of the Friedmann equation to include phantom power (w < -1), textures (w = -2/3) and curvature are considered, and constraints on these dark energy contributors from supernova observations are derived. Modified values for the density of matter inferred from cosmic density perturbations and from the CMB under these circumstances are also estimated, as exemplified by 2df and SDSS.
Context. Our Local Group of galaxies appears to be moving relative to the cosmic microwave background with the source of the peculiar motion still uncertain. While in the past this has been studied mostly using galaxies as distance indicators, the weight of type Ia supernovae (SNe Ia) has increased recently with the continuously improving statistics of available low-redshift supernovae. Aims. We measured the bulk flow in the nearby universe ($0.015 < z < 0.1$) using 117 SNe Ia observed by the Nearby Supernova Factory, as well as the Union2 compilation of SN Ia data already in the literature. M…
A cosmological model, in which the cosmic microwave background (CMB) is a thermal radiation of intergalactic dust instead of a relic radiation of the Big Bang, is revived and revisited. The model suggests that a virtually transparent local Universe becomes considerably opaque at redshifts $z > 2-3$. Such opacity is hardly to be detected in the Type Ia supernova data, but confirmed using quasar data. The opacity steeply increases with redshift because of a high proper density of intergalactic dust in the previous epochs. The temperature of intergalactic dust increases as $(1+z)$ and exactly com…
In this paper, using and implementing a new line of sight CMB code, called CMBAns [1], that allows us to modify H(z) for any given feature at any redshift we study the effect of changes in the expansion history of the Universe on the CMB power spectrum. Motivated by the detailed analytical calculations of the effects of the changes in H(z) on ISW plateau and CMB low multipoles, we study two phenomenological parametric form of the expansion history using WMAP data and through MCMC analysis. Our MCMC analysis shows that the standard LCDM cosmological model is consistent with the CMB data allowin…
Cosmology has made enormous progress through studies of the cosmic microwave background, however the subtle signals being now sought such as B-mode polarisation due to primordial gravitational waves are increasingly hard to disentangle from residual Galactic foregrounds in the derived CMB maps. We revisit our finding that on large angular scales there are traces of the nearby old supernova remnant Loop I in the WMAP 9-year map of the CMB and confirm this with the new SMICA map from the Planck satellite.
$H_0$ Without the Sound Horizon (or Supernovae): A 2% Measurement in DESI DR1
The Ohio State University（俄亥俄州立大学）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；CEA, Université Paris-Saclay（法国原子能委员会，巴黎萨克雷大学）；University of Waterloo（滑铁卢大学）；Perimeter Institute for Theoretical Physics（理论物理前沿研究所）
We examine the cosmological implications of measurements of the void-galaxy cross-correlation at redshift $z=0.57$ combined with baryon acoustic oscillation (BAO) data at $0.1<z<2.4$. We find direct evidence of the late-time acceleration due to dark energy at $>10σ$ significance from these data alone, independent of the cosmic microwave background and supernovae. Using a nucleosynthesis prior on $Ω_bh^2$, we measure the Hubble constant to be $H_0=72.3\pm1.9\;{\rm km\,s}^{-1}{\rm Mpc}^{-1}$ from BAO+voids at $z<2$, and $H_0=69.0\pm1.2\;{\rm km\,s}^{-1}{\rm Mpc}^{-1}$ when adding Lyman-$α$ BAO a…
