Combined analysis of Planck and SPTPol data favors the early dark energy models
Anton Chudaykin, Dmitry Gorbunov, Nikita Nedelko
备注：
28+6 pages, 6 figures, 3+3 tables. SPTPol likelihoods for montepython environment are available at https://github.com/ksardase/SPTPol-montepython. v2: major revision which includes chi2 analysis for each likelihood in LCDM and EDE fits, detailed comparison with previous works and various clarifications. The results are unchanged. v3: minor corrections, accepted in JCAP
We study the implications of the Planck temperature power spectrum at low multipoles, $\ell<1000$, and SPTPol data. We show that this combination predicts consistent lensing-induced smoothing of acoustic peaks within $Λ$CDM cosmology and yields the robust predictions of the cosmological parameters. Combining only the Planck large-scale temperature data and the SPTPol polarization and lensing measurements within $Λ$CDM model we found substantially lower values of linear matter density perturbation $σ_8$ which bring the late-time parameter $S_8=σ_8\sqrt{Ω_m/0.3}=0.763\pm0.022$ into accordance with galaxy clustering and weak lensing measurements. It also raises up the Hubble constant $H_0=69.68\pm1.00{\rm \,\,km\,s^{-1}Mpc^{-1}}$ that reduces the Hubble tension to the $2.5σ$ level. We examine the residual tension in the Early Dark Energy (EDE) model which produces the brief energy injection prior to recombination. We implement both the background and perturbation evolutions of the scalar field which potential scales as $V(ϕ)\propto ϕ^{2n}$. Including cosmic shear measurements (KiDS, VIKING-450, DES) and local distance-ladder data (SH0ES) to the combined fit we found that EDE completely alleviates the Hubble tension while not degradating the fit to large-scale structure data. The EDE scenario significantly improves the goodness-of-fit by $2.9σ$ in comparison with the concordance $Λ$CDM model. The account for the intermediate-redshift data (the supernova dataset and baryon acoustic oscillation data) fits perfectly to our parameter predictions and indicates the preference of EDE over $Λ$CDM at $3σ$.
We use six tilted spatially-flat and untilted non-flat dark energy cosmological models in analyses of South Pole Telescope polarization (SPTpol) cosmic microwave background (CMB) data, alone and in combination with Planck 2015 CMB data and non-CMB data, namely, the Pantheon Type Ia supernovae apparent magnitudes, a collection of baryon acoustic oscillation data points, Hubble parameter measurements, and growth rates. Although the cosmological models that best-fit the Planck CMB and non-CMB data do not provide good fits to the SPTpol data, with the $χ^2$'s exceeding the expected value, given th…
A promising idea to resolve the long standing Hubble tension is to postulate a new subdominant dark-energy-like component in the pre-recombination Universe which is traditionally termed as the Early Dark Energy (EDE). However, as shown in Refs. \cite{Hill:2020osr,Ivanov:2020ril} the cosmic microwave background (CMB) and large-scale structure (LSS) data impose tight constraints on this proposal. Here, we revisit these strong bounds considering the Planck CMB temperature anisotropy data at large angular scales and the SPTPol polarization and lensing measurements. As advocated in Ref. \cite{Chuda…
The Hubble tension might be resolved by injecting a new energy component, called Early Dark Energy (EDE), prior to recombination. An Anti-de Sitter (AdS) phase around recombination can make the injected energy decay faster, which thus allows a higher EDE fraction (so larger $H_0$) while prevents degrading the CMB fit. In this work, we test the AdS-EDE model with CMB and Large-Scale Structure (LSS) data. Our CMB dataset consists of low-$\ell$ part of Planck TT spectrum and SPTpol polarization and lensing measurements, since this dataset predicts the CMB lensing effect consistent with $Λ$CDM exp…
We present cosmological constraints based on the cosmic microwave background (CMB) lensing potential power spectrum measurement from the recent 500 deg$^2$ SPTpol survey, the most precise CMB lensing measurement from the ground to date. We fit a flat $Λ$CDM model to the reconstructed lensing power spectrum alone and in addition with other data sets: baryon acoustic oscillations (BAO) as well as primary CMB spectra from Planck and SPTpol. The cosmological constraints based on SPTpol and Planck lensing band powers are in good agreement when analysed alone and in combination with Planck full-sky …
First constraints on causal sources of primordial gravitational waves from BICEP/Keck, SPTpol, SPT-3G, Planck and WMAP $B$-mode data
Fermi National Accelerator Laboratory（费米国家加速器实验室）；Kavli Institute for Cosmological Physics, University of Chicago（芝加哥大学卡弗里宇宙物理研究所）；Leinweber Institute for Theoretical Physics, Stanford University（斯坦福大学莱因韦伯理论物理研究所）；School of Physics, University of Melbourne（墨尔本大学物理学院）；Department of Physics and Astronomy, Seoul National University（首尔大学物理与天文学系）；Department of Astronomy and Astrophysics, University of Chicago（芝加哥大学天文与天体物理学系）；Department of Physics and Astronomy, University of Notre Dame（圣母大学物理与天文学系）；Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris（索邦大学，法国国家科学研究中心，UMR 7095，巴黎天体物理研究所）
The E-mode (EE) CMB power spectra measured by Planck, ACTPol, and SPTpol constrain the Hubble constant to be $70.0\pm2.7$, $72.4^{+3.9}_{-4.8}$, and $73.1^{+3.3}_{-3.9}$ km s$^{-1}$ Mpc$^{-1}$ within the standard $Λ$CDM model (posterior mean and central 68% interval bounds). These values are higher than the constraints from the Planck temperature (TT) power spectrum, and consistent with the Cepheid-supernova distance ladder measurement $H_0=73.2\pm1.3$ km s$^{-1}$ Mpc$^{-1}$. If this preference for a higher value was strengthened in a joint analysis it could provide an intriguing hint at the r…
We present measurements of the $E$-mode polarization angular auto-power spectrum ($EE$) and temperature-$E$-mode cross-power spectrum ($TE$) of the cosmic microwave background (CMB) using 150 GHz data from three seasons of SPTpol observations. We report the power spectra over the spherical harmonic multipole range $50 < \ell \leq 8000$, and detect nine acoustic peaks in the $EE$ spectrum with high signal-to-noise ratio. These measurements are the most sensitive to date of the $EE$ and $TE$ power spectra at $\ell > 1050$ and $\ell > 1475$, respectively. The observations cover 500 deg$^2$, a fiv…
We report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses 500 deg$^2$ of SPTpol data, a five-fold increase over the last SPTpol B-mode release. As a result, the bandpower uncertainties have been reduced by more than a factor of two, and the measurement extends to lower multipoles: $52 < \ell < 2301$. Data from both 95 and 150 GHz are used, allowing for three cross-spectra: 95 GHz x 95 GHz, 95 GHz x 150 GHz, and 150 GHz x 150 GHz. B-mode power is detec…
We present measurements of $E$-mode polarization and temperature-$E$-mode correlation in the cosmic microwave background (CMB) using data from the first season of observations with SPTpol, the polarization-sensitive receiver currently installed on the South Pole Telescope (SPT). The observations used in this work cover 100~\sqdeg\ of sky with arcminute resolution at $150\,$GHz. We report the $E$-mode angular auto-power spectrum ($EE$) and the temperature-$E$-mode angular cross-power spectrum ($TE$) over the multipole range $500 < \ell \leq5000$. These power spectra improve on previous measurem…
We present a measurement of the cosmic microwave background (CMB) lensing potential using 500 deg$^2$ of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles $L \lesssim 250$, using a quadratic estimator on a combination of CMB temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of $100< L < 2000$ from sets of temperature-only, polarization-only, and minimum-variance estimators. We measure the lensing am…
We report new measurements of millimeter-wave power spectra in the angular multipole range $2000 \le \ell \le 11,000$ (angular scales $5^\prime \gtrsim θ\gtrsim 1^\prime$). By adding 95 and 150\,GHz data from the low-noise 500 deg$^2$ SPTpol survey to the SPT-SZ three-frequency 2540 deg$^2$ survey, we substantially reduce the uncertainties in these bands. These power spectra include contributions from the primary cosmic microwave background, cosmic infrared background, radio galaxies, and thermal and kinematic Sunyaev-Zel'dovich (SZ) effects. The data favor a thermal SZ (tSZ) power at 143\,GHz…
We investigate early dark energy models in the context of the lensing anomaly by considering two different Cosmic Microwave Background (CMB) datasets: a complete Planck, and a second one primarily based on SPTPol and Planck temperature ($l<1000$). We contrast the effects of allowing the phenomenological lensing amplitude ($\Al$) to be different from unity. We find that the fraction of early dark energy, while not immediately affected by the lensing anomaly, can induce mild deviations, through correlations with the parameters $H_0$ and $S_8$. {We extend the analysis also by marginalizing the Ne…
Exploring $Λ$CDM extensions with SPT-3G and Planck data: 4$σ$ evidence for neutrino masses and implications of extended dark energy models for cosmological tensions
The Planck collaboration has recently published maps of the Cosmic Microwave Background radiation with the highest precision. In the standard flat $Λ$CDM framework, Planck data show that the Hubble constant $H_0$ is in tension with that measured by the several direct probes on $H_0$. In this paper, we perform a global analysis from the current observational data in the general dark energy models and find that resolving this tension on $H_0$ requires the dark energy model with its equation of state (EoS) $w\neq-1$. Firstly, assuming the $w$ to be a constant, the Planck data favor $w < -1$ at ab…
Constraints on inflationary scenarios and isocurvature perturbations have excluded the simplest and most generic models of dark matter based on QCD axions. Considering non-minimal kinetic couplings of scalar fields to gravity substantially changes this picture. The axion can account for the observed dark matter density avoiding the overproduction of isocurvature fluctuations. Finally, we show that assuming the same non-minimal kinetic coupling to the axion (dark matter) and to the standard model Higgs boson (inflaton) provides a minimal picture of early time cosmology.
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…
With the Planck 2015 result, most of the well known canonical large field inflation models turned out to be strongly disfavored. Axion inflation is one of such models which is becoming marginalized with the increasing precession of CMB data. In this paper, we have shown that with a simple Galileon type modification to the marginally favored axion model calling G-axion, we can turn them into one of the most favored models with its detectable prediction of $r$ and $n_s$ within its PLANCK $1σ$ range for a wide range of parameters. Interestingly it is this modification which plays the important ro…
We describe the observations and resultant galaxy cluster catalog from the 2770 deg$^2$ SPTpol Extended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev-Zel'dovich (SZ) effect, and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete followup we have confirmed as clusters 244 of 266 candidates at a detection significance $ξ\ge 5$ and an additional 204 systems at $4<ξ<5$. The confirmed sample has a median mass of $M_{500c} \sim {4.4 \times 10^{14} M_\odot h_{70}^{-1}}$, a median re…
The Hubble tension and attempts to resolve it by modifying the physics of (or at) recombination motivate finding ways to determine $H_0$ and the sound horizon at the epoch of baryon decoupling $r_{\rm d}$ in ways that neither rely on a recombination model nor on late-time Hubble data. In this work, we investigate what one can learn from the current and future BAO data when treating $r_{\rm d}$ and $H_0$ as independent free parameters. It is well known that BAO gives exquisite constraints on the product $r_{\rm d}H_0$. We show here that imposing a moderate prior on $Ω_{\rm m} h^2$ breaks the de…
We study the relationship between signatures of high redshift ionization in large-angle CMB polarization power spectra and features in the Planck 2015 data. Using a principal component (PC) ionization basis that is complete to the cosmic variance limit out to $z_{\rm max}=30,40,50$, we find a robust $>95\%$ CL preference for ionization at $z>15$ with no preference for $z>40$. This robustness originates from the $\ell \sim 10$ region of the data which show high power relative to $\ell \le 8$ and result in a poor fit to a steplike model of reionization. Instead by allowing for high redshift reio…
The '$S_8$ tension' is a longstanding discrepancy between the cosmic microwave background (CMB) and weak gravitational lensing determination of the amplitude of matter fluctuations, parametrized as $S_8\equivσ_8(Ω_m/0.3)^{0.5}$, where $σ_8$ is the root mean square of matter fluctuations on a 8 $h^{-1}$Mpc scale, and $Ω_m$ is the total matter abundance. It was recently shown that dark matter (DM) decaying into a massless (dark radiation) and a massive (warm DM) species, with a lifetime $Γ^{-1} \simeq 55~(\varepsilon/0.007)^{1.4}$ Gyrs -- where $\varepsilon$ represent the mass-energy fraction tr…
Compensated isocurvature perturbations (CIP), where the baryon and cold dark matter perturbations cancel, do not cause total matter isocurvature perturbation. Consequently, at the linear order in the baryon density contrast $Δ$, CIP is not detectable by the CMB power spectra. At the second order CIP smoothes the power spectra in a similar manner as lensing, causing a degeneracy between the CIP variance $Δ^2_{rms}=<Δ^2>$ and lensing parameter $A_L$. We show that the CMB lensing data breaks this degeneracy. Nested sampling of the LCDM+CIP(+$A_L$) model, the Planck 2015 temperature, polarization,…
We update the cosmological parameter estimation for three non-vanilla models by a joint analysis of \CCCP\ X-ray cluster, the newly released \Planck\ CMB data as well as some external data sets, such as baryon acoustic oscillation measurements from the 6dFGS, SDSS DR7 and BOSS DR9 surveys, and Hubble Space Telescope $H_0$ measurement. First of all, we find that X-ray cluster data sets strongly favor a non-zero summed neutrino mass at more than 3$σ$ confidence level in these non-vanilla models. And then, we reveal some tensions between X-ray cluster and {\it Planck} data in some cosmological pa…
Accurate cosmological parameter estimates using polarization data of the cosmic microwave background (CMB) put stringent requirements on map calibration, as highlighted in the recent results from the Planck satellite. In this paper, we point out that a model-dependent determination of polarization calibration can be achieved by the joint fit of the TE and EE CMB power spectra. This provides a valuable cross-check to band-averaged polarization efficiency measurements determined using other approaches. We demonstrate that, in $Λ$CDM, the combination of the TE and EE constrain polarization calibr…
We investigate the origin of $Λ$CDM parameter constraints in weak lensing, with a focus on the Hubble constant. We explain why current cosmic shear data are sensitive to the parameter combination $S_8 \propto σ_8 Ω_m^{0.5}$, improving upon previous studies through use of the halo model. Motivated by the ongoing discrepancy in measurements of the Hubble constant from high and low redshift, we explain why cosmic shear provides almost no constraint on $H_0$ by showing how the lensing angular power spectrum depends on physical length scales in the dark matter distribution. We derive parameter cons…
We show that a combination of the simplest $α$-attractors and KKLTI models related to Dp-brane inflation covers most of the area in the ($n_{s}$, $r$) space favored by Planck 2018. For $α$-attractor models, there are discrete targets $3α=1,2,...,7$, predicting 7 different values of $r = 12α/N^{2}$ in the range $10^{-2} \gtrsim r \gtrsim 10^{-3}$. In the small $r$ limit, $α$-attractors and Dp-brane inflation models describe vertical $β$-stripes in the ($n_{s}$, $r$) space, with $n_{s}=1-β/N$, $β=2, {5\over 3},{8\over 5}, {3\over 2},{4\over 3}$. A phenomenological description of these models and…
We investigate the observational constraints on the interacting holographic dark energy model. We consider five typical interacting models with the interaction terms $Q=3βHρ_{\rm{de}}$, $Q=3βHρ_{\rm{c}}$, $Q=3βH(ρ_{\rm{de}}+ρ_{\rm c})$, $Q=3βH\sqrt{ρ_{\rm{de}}ρ_{\rm c}}$, and $Q=3βH\frac{ρ_{\rm{de}}ρ_{c}}{ρ_{\rm{de}}+ρ_{\rm c}}$, respectively, where $β$ is a dimensionless coupling constant. The observational data we use in this paper include the JLA compilation of type Ia supernovae data, the Planck 2015 distance priors data of cosmic microwave background observation, the baryon acoustic oscil…
Recently, the Planck collaboration has released the first cosmological papers providing the highest resolution, full sky, maps of the cosmic microwave background (CMB) temperature anisotropies. In this paper we study a phenomenological model which interpolates between the pure $Λ$CDM model and the Dvali-Gabadadze-Porrati (DGP) braneworld model with an additional parameter $α$. Firstly, we calculate the "distance information" of Planck data which includes the "shift parameter" $R$, the "acoustic scale" $l_A$, and the photon decoupling epoch $z_\ast$ in different cosmological models and find tha…
In this work, we examine cosmological constraints on models of composite inflation based on the slow-roll approximation by using the recent Planck measurement. We compare the spectral index of curvature perturbation (and its running) and the tensor-to-scalar ratio predicted by such models with Planck 2015 data. We find that the predictions of technicolor inflation are nicely consistent with the Planck analysis. Moreover, the predictions from the second model, glueball inflation, are in good agreement with the Planck data at $2σ$C.L. However, the final two models, super glueball inflation and o…
We use the latest Planck constraints, and in particular constraints on the derived parameters (Hubble constant and age of the Universe) for the local universe and compare them with local measurements of the same quantities. We propose a way to quantify whether cosmological parameters constraints from two different experiments are in tension or not. Our statistic, T, is an evidence ratio and therefore can be interpreted with the widely used Jeffrey's scale. We find that in the framework of the LCDM model, the Planck inferred two dimensional, joint, posterior distribution for the Hubble constant…
I give a general review of inflationary cosmology and of its present status, in view of the 2013 data release by the Planck satellite. A specific emphasis is given to the new broad class of theories, the cosmological attractors, which have nearly model-independent predictions converging at the sweet spot of the Planck data in the (n_s,r) plane. I also discuss the problem of initial conditions for the theories favored by the Planck data.
Shifted Hybrid Realization of Non-Minimal Higgs Inflation in Light of ACT DR6 and Planck Data
Università degli Studi di Padova（帕多瓦大学）；INFN, Sezione di Padova（意大利国家核物理研究所帕多瓦分部）；CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所理论物理重点实验室）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；Department of Physics, Faculty of Science, Islamic University of Madinah（麦地那伊斯兰大学理学院物理系）
We explore the relationship between features in the Planck 2015 temperature and polarization data, shifts in the cosmological parameters, and features from inflation. Residuals in the temperature data at low multipole $\ell$, which are responsible for the high $H_0\approx 70$ km s$^{-1}$Mpc$^{-1}$ and low $σ_8Ω_m^{1/2}$ values from $\ell<1000$ in power-law $Λ$CDM models, are better fit to inflationary features with a $1.9σ$ preference for running of the running of the tilt or a stronger $99\%$ CL local significance preference for a sharp drop in power around $k=0.004$ Mpc$^{-1}$ in generalized…
While the observed nearly scale-invariant initial power spectrum is regarded as one of the favorable evidence of the standard inflationary cosmology, precision observations of the Cosmic Microwave Background (CMB) anisotropies also suggest possible existence of nontrivial features such as those observed around multipoles $\ell\sim120$ by WMAP. Here, we examine the Planck data and investigate the effects of these features on the cosmological parameter estimation performing the Markov-Chain Monte-Carlo (MCMC) analysis. We find that the features exist in the Planck data at the same position as th…
We derive distance priors from Planck first data release, and examine their impact on dark energy constraints from current observational data. We give the mean values and covariance matrix of {R, l_a, Ω_b h^2, n_s}, which give an efficient summary of Planck data. The CMB shift parameters are R=\sqrt{Ω_m H_0^2}\,r(z_*), and l_a=πr(z_*)/r_s(z_*), where z_* is the redshift at the last scattering surface, and r(z_*) and r_s(z_*) denote our comoving distance to z_* and sound horizon at z_* respectively. We find that Planck distance priors are significantly tighter than those from WMAP9. However, ad…
Recently, the Planck satellite found a larger and most precise value of the matter energy density, that impacts on the present values of other cosmological parameters such as the Hubble constant, the present cluster abundances and the age of the Universe. The existing tension between Planck determination of these parameters in the frame of the base LambdaCDM model and their direct measurements generated lively discussions and several interpretations. In this paper we quantify this tension by exploring several extensions of the base LambdaCDM model that include the leptonic asymmetry. We set bo…
We investigate the implications for inflation of the detection of B-modes polarization in the Cosmic Microwave Background (CMB) by BICEP2. We show that the hypothesis of primordial origin of the measurement is only favored by the first four bandpowers, while the others would prefer unreasonably large values of the tensor-to-scalar ratio. Using only those four bandpowers, we carry out a complete analysis in the cosmological and inflationary slow-roll parameter space using the BICEP2 polarization measurements alone and extract the Bayesian evidences and complexities for all the Encyclopaedia Inf…
We study the performance of three pairs of tilted $Λ$CDM cosmological models, two pairs allowing for non-flat spatial hypersurfaces with CMB temperature and polarization power spectrum data (P18) from Planck, P18 lensing (lensing), and non-CMB data (non-CMB). For the six models, we measure cosmological parameters and study whether or not pairs of the data sets are mutually consistent in these models. Half of these models allow the lensing consistency parameter $A_L$ to be an additional free parameter, while the other three have $A_L = 1$. The tilted spatially-flat models assume the usual primo…
We present measurements of the $E$-mode ($EE$) polarization power spectrum and temperature-$E$-mode ($TE$) cross-power spectrum of the cosmic microwave background using data collected by SPT-3G, the latest instrument installed on the South Pole Telescope. This analysis uses observations of a 1500 deg$^2$ region at 95, 150, and 220 GHz taken over a four month period in 2018. We report binned values of the $EE$ and $TE$ power spectra over the angular multipole range $300 \le \ell < 3000$, using the multifrequency data to construct six semi-independent estimates of each power spectrum and their m…
We investigate the impact of astrophysical systematics on cosmic shear cosmological parameter constraints from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), and the concordance with cosmic microwave background measurements by Planck. We present updated CFHTLenS cosmic shear tomography measurements extended to degree scales using a covariance calibrated by a new suite of N-body simulations. We analyze these measurements with a new model fitting pipeline, accounting for key systematic uncertainties arising from intrinsic galaxy alignments, baryonic effects in the nonlinear matter…
Nonstandard self-interactions can alter the evolution of cosmological neutrinos, mainly by damping free streaming, which should leave traces in cosmological observables. Although overall effects are opposite to those produced by neutrino mass and a larger $N_{\rm eff}$, they cannot be totally canceled by these last. We harness cosmological data that includes Cosmic Microwave Background from Plank 2018, BAO measurements, local $H_0$, Ly-$α$ and SNIa, to constrain massive neutrino self-interactions with a very light scalar mediator. We find that the effective coupling constant, at the 95\% C.L.,…
We investigate the allowed range of reheating temperature values in light of the Planck 2015 results and the recent joint analysis of Cosmic Microwave Background (CMB) data from the BICEP2/Keck Array and Planck experiments, using monomial and binomial inflationary potentials. While the well studied $ϕ^2$ inflationary potential is no longer favored by current CMB data, as well as $ϕ^p$ with $p>2$, a $ϕ^1$ potential and canonical reheating ($w_{re}=0$) provide a good fit to the CMB measurements. In this last case, we find that the Planck 2015 $68\%$ confidence limit upper bound on the spectral i…
Primordial isocurvature fluctuations between photons and either neutrinos or non-relativistic species such as baryons or dark matter are known to be sub-dominant to adiabatic fluctuations. Perturbations in the relative densities of baryons and dark matter (known as compensated isocurvature perturbations, or CIPs), however, are surprisingly poorly constrained. CIPs leave no imprint in the cosmic microwave background (CMB) on observable scales, at least at linear order in their amplitude and zeroth order in the amplitude of adiabatic perturbations. It is thus not yet empirically known if baryons…
The observational status of inflation after the Planck 2013 and 2015 results and the BICEP2/Keck Array and Planck joint analysis is discussed. These pedagogical lecture notes are intended to serve as a technical guide filling the gap between the theoretical articles on inflation and the experimental works on astrophysical and cosmological data. After a short discussion of the central tenets at the basis of inflation (negative self-gravitating pressure) and its experimental verifications, it reviews how the most recent Cosmic Microwave Background (CMB) anisotropy measurements constrain cosmic i…
We test extensions to the standard cosmological model with weak gravitational lensing tomography using 450 deg$^2$ of imaging data from the Kilo Degree Survey (KiDS). In these extended cosmologies, which include massive neutrinos, nonzero curvature, evolving dark energy, modified gravity, and running of the scalar spectral index, we also examine the discordance between KiDS and cosmic microwave background measurements from Planck. The discordance between the two datasets is largely unaffected by a more conservative treatment of the lensing systematics and the removal of angular scales most sen…
In this paper, we loosen the zero equation of state of dark matter to a constant $w_{dm}$. By using the currently available cosmic observations which include the type-Ia supernovae, the baryon acoustic oscillation, the WiggleZ measurements of matter power spectrum and the cosmic microwave background radiation from the firs release of {\it Planck} dat through the Markov chain Monte Carlo method, we found the equation of state of dark matter in $3σ$ regions: $w_{dm}=0.000707_{-0.000747-0.00149-0.00196}^{+0.000746+0.00146+0.00193}$. The difference of the minimum $χ^2$ between the $Λ$CDM and $Λ$wD…
The primordial CMB at small angular scales is sensitive to the ionization and expansion history of the universe around the time of recombination. This dependence has been exploited to constrain the helium abundance and the effective number of relativistic species. Here we focus on allowed ionization fraction trajectories, $\Xe (z)$, by constraining low-order principal components of perturbations to the standard recombination scenario ($\Xe$-eigenmodes) in the circa 2011 SPT, ACT and WMAP7 data. Although the trajectories are statistically consistent with the standard recombination, we find that…
In this paper, we make a comparison for the impacts of smooth dynamical dark energy, modified gravity, and interacting dark energy on the cosmological constraints on the total mass of active neutrinos. For definiteness, we consider the $Λ$CDM model, the $w$CDM model, the $f(R)$ model, and two typical interacting vacuum energy models, i.e., the I$Λ$CDM1 model with $Q=βHρ_{\rm c}$ and the I$Λ$CDM2 model with $Q=βHρ_Λ$. In the cosmological fits, we use the Planck 2015 temperature and polarization data, in combination with other low-redshift observations including the baryon acoustic oscillations,…
Cosmic reionization holds the key to understand structure formation in the Universe, and can inform us about the properties of the first sources, as their star formation efficiency and escape fraction of ionizing photons. By combining the recent release of Planck electron scattering optical depth data with observations of high-redshift quasar absorption spectra, we obtain strong constraints on viable reionization histories. We show that inclusion of Planck data favors a reionization scenario with a single stellar population. The mean $x_{\rm HI}$ drops from $\sim0.8$ at $z=10.6$ to $\sim10^{-4…
In this work, predictions of the Ginzburg-Landau theory of dark energy (GLT) for CMB lensing are studied. We find that the time and scale dependence of the dark energy fluctuations in this semi-phenomenological model is favored by data in several ways. Firstly, unlike $Λ$CDM, $\ell\leq801$ and $\ell>801$ ranges of the CMB angular power spectrum are consistent in this framework. Secondly, the lensing amplitude $A_L$ is completely consistent with unity when GLT is confronted with CMB data, even without including CMB lensing data. Therefore lensing anomaly is absent in this model. Furthermore, th…
We study initial conditions for inflation in scenarios where the inflaton potential has a plateau shape. Such models are those most favored by Planck data and can be obtained in a large number of model classes. As a representative example, we consider Higgs inflation with and without an $R^2$ term in the context of Palatini gravity. We show that inflation with a large number of e-folds generically occurs in a large part of the parameter space without any fine-tuning of parameters even when the scale of inflation and the inflaton field value during inflation are much smaller than the Planck sca…
We wish to investigate whether there is an extension to the base $Λ$CDM cosmology that can resolve the tension between the Planck observation of the cosmic microwave background anisotropies and the local measurement of the Hubble constant. We consider various plausible extended models in this work, and we use the Planck 2015 observation, combined with the baryon acoustic oscillation data, the JLA type Ia supernovae data, and the local measurement of the Hubble constant (by Riess et al. in 2016), to make an analysis. We find that the holographic dark energy plus sterile neutrino model can reduc…
The current most accepted paradigm for the early universe cosmology, the inflationary scenario, shows a good agreement with the recent Cosmic Microwave Background (CMB) and polarization data. However, when the inflation consistency relation is relaxed, these observational data exclude a larger range of red tensor tilt values, prevailing the blue ones which are not predicted by the minimal inflationary models. Recently, it has been shown that the assumption of spatial diffeomorphism invariance breaking (SDB) in the context of an effective field theory of inflation leads to interesting observati…
Recently there has been reports of finding a lower bound on the neutrino mass parameter ($Σm_ν$) when using ACT and SPTpol data however these bounds on the $Σm_ν$ are still weaker for most case around at 1 $σ$ level. In this context, here in this work, we study the consequences of using an enlarged four parameter dynamical dark energy equation of state on neutrino mass parameter as well as on the Hubble and S8 tensions. The four parameter dark energy equation of state incorporates a generic non-linear monotonic evolution of the dark energy equation of state, where the four parameters are the e…
We consider a quintessence model with Yukawa interaction between dark energy and dark matter and constrain this model by employing the recent cosmological data including the updated cosmic microwave background (CMB) measurements from Planck 2015, the weak gravitational lensing measurements from Kilo Degree Survey (KiDS) and redshift-space distortions. We find that an interaction in the dark sector is compatible with observations. The updated Planck data can significantly improve the constraints compared with the previous results from Planck 2013, while the KiDS data has less constraining power…
