Taking the neutrino oscillation data into consideration, a dimensionless parameter $Δ= (m_3-m_1)/(m_3+m_1)$ is adopted to parameterize the three neutrino mass eigenstates and the normal (positive $Δ$) or inverted (negative $Δ$) mass hierarchies in three typical cosmological models. Using the currently available cosmic observational data, several Markov Chain Monte Carlo chains are obtained with uniform priors on the free parameters at first. Applying importance sampling the results are compared with three new priors, i.e., logarithmic prior on $|Δ|$, linear and logarithmic priors on $Σm_ν$. It turns out that the three new priors increase the upper limits of neutrino mass, but do not change the tendency towards different model's preference for different hierarchies, i.e., the normal hierarchy tends to be favored by $Λ$CDM and $w$CDM, which, however, disappears in the $w_0 w_a$CDM model. In addition, the almost symmetrical contours in the $w-Δ$, $w_0-Δ$, $w_a-Δ$ planes indicate that the normal and inverted hierarchy have strong degeneracy. Finally, we perform a Bayesian model comparison analysis, finding that flat linear prior on $Δ$ and $w_0 w_a$CDM are the most preferred prior and model, respectively.
We investigate the interacting dark energy models by using the diagnostics of statefinder hierarchy and growth rate of structure. We wish to explore the deviations from $Λ$CDM and to differentiate possible degeneracies in the interacting dark energy models with the geometrical and structure growth diagnostics. We consider two interacting forms for the models, i.e., $Q_1=βHρ_c$ and $Q_2=βHρ_{de}$, with $β$ being the dimensionless coupling parameter. Our focus is the I$Λ$CDM model that is a one-parameter extension to $Λ$CDM by considering a direct coupling between the vacuum energy ($Λ$) and col…
The Evolutionary Map of the Universe (EMU) is an all-sky survey in radio-continuum which uses the Australian SKA Pathfinder (ASKAP). Using galaxy angular power spectrum and the integrated Sachs-Wolfe effect, we study the potential of EMU to constrain models beyond $Λ$CDM (i.e., local primordial non-Gaussianity, dynamical dark energy, spatial curvature and deviations from general relativity), for different design sensitivities. We also include a multi-tracer analysis, distinguishing between star-forming galaxies and galaxies with an active galactic nucleus, to further improve EMU's potential. W…
We apply the statefinder hierarchy plus the fractional growth parameter to explore the extended Ricci dark energy (ERDE) model, in which there are two independent coefficients $α$ and $β$. By adjusting them, we plot evolution trajectories of some typical parameters, including Hubble expansion rate $E$, deceleration parameter $q$, the third and fourth order hierarchy $S_3^{(1)}$ and $S_4^{(1)}$ and fractional growth parameter $ε$, respectively, as well as several combinations of them. For the case of variable $α$ and constant $β$, in the low-redshift region the evolution trajectories of $E$ are…
Weak lensing convergence statistics is a powerful tool to probe dark energy. Dark energy plays an important role to the structure formation and the effects can be detected through the convergence power spectrum, bi-spectrum etc. One of the most promising and simplest dark energy model is the $ Λ$CDM. However, it is worth investigating different dark energy models with evolving equation of state of the dark energy. In this work, detectability of different dark energy models from $ Λ$CDM model has been explored through convergence power spectrum and bi-spectrum.
Recently, some divergent conclusions about cosmic acceleration were obtained using type Ia supernovae (SNe Ia), with opposite assumptions on the intrinsic luminosity evolution. In this paper, we use strong gravitational lensing systems to probe the cosmic acceleration. Since the theory of strong gravitational lensing is established certainly, and the Einstein radius is determined by stable cosmic geometry. We study two cosmological models, $Λ$CDM and power-law models, through 152 strong gravitational lensing systems, incorporating with 30 Hubble parameters $H(z)$ and 11 baryon acoustic oscilla…
In this work we update the bounds on $\sum m_ν$ from latest publicly available cosmological data and likelihoods using Bayesian analysis, while explicitly considering particular neutrino mass hierarchies. In the minimal $Λ\textrm{CDM}+\sum m_ν$ model with most recent CMB data from Planck 2018 TT,TE,EE, lowE, and lensing; and BAO data from BOSS DR12, MGS, and 6dFGS, we find that at 95\% C.L. the bounds are: $\sum m_ν<0.12$ eV (degenerate), $\sum m_ν<0.15$ eV (normal), $\sum m_ν<0.17$ eV (inverted). The bounds vary across the different mass orderings due to different priors on $\sum m_ν$. Also, …
The Universe's initial conditions, in particular baryon and cold dark matter (CDM) isocurvature perturbations, are poorly constrained on sub-Mpc scales. In this paper, we develop a new formalism to compute the effect of small-scale baryon perturbations on the mean free-electron abundance, thus on cosmic microwave background (CMB) anisotropies. Our framework can accommodate perturbations with arbitrary time and scale dependence. We apply this formalism to four different combinations of baryon and CDM isocurvature modes, and use Planck CMB-anisotropy data to probe their initial amplitude. We fin…
Probing late-time deviations from $Λ$CDM with a quadratic dark energy expansion
Plaksha University（普拉克斯哈大学）；Universidade Federal do Paraná（巴拉那联邦大学）；Federal University of Latin American Integration (UNILA)（拉丁美洲联邦大学）；Universidade Federal do Rio Grande do Sul（南里奥格兰德联邦大学）；Instituto Nacional de Pesquisas Espaciais（国家空间研究所）
One of the algorithms typically used for fitting anisotropic Baryon Acoustic Oscillations (BAO), $α_{\perp}D_{M, \text{fid}}(z)/r_{d, \text{fid}}=D_{M}(z)/r_{d}$, provides an excellent fit as $z\Rightarrow 0$. Yet, at $ z_{\text{drag}} \simeq 1060$, $D_{M, \text{fid}}(1060)/r_{d, \text{fid}}\simeq D_{M}(1060)/r_{d}$. Since $α_{\perp}$ does not change with increasing redshift, we conclude that the algorithms deviate from true solutions with increasing $z$. We investigate that departure through an assumption of a flat $Λ$CDM cosmology. At the relatively low redshifts at which isotropic BAO studi…
Unlike the electromagnetic radiation from astrophysical objects, gravitational waves (GWs) from binary star mergers have much longer wavelengths and are coherent. For ground-based GW detectors, when the lens object between the source and the earth has mass $\sim 1-10^5M_\odot$, the diffraction effect should be considered since the chirping wavelengths are comparable to the scale of the barrier (its Schwarzschild radius). The waveform will thus be distorted as the fringes. In this work, we show that signals from the third-generation GW detectors like the Einstein Telescope (ET) would be a smoki…
We update the constraints on the cosmological parameters by adopting the Planck data released in 2015 and Baryon Acoustic Oscillation (BAO) measurements including the new DR14 quasar sample measurement at redshift $z=1.52$, and we conclude that the based six-parameter $Λ$CDM model is preferred. Exploring some extensions to the $Λ$CDM models, we find that the equation of state of dark energy reads $w=-1.036\pm 0.056$ in the $w$CDM model, the effective relativistic degrees of freedom in the Universe is $N_\text{eff}=3.09_{-0.20}^{+0.18}$ in the $N_\text{eff}+Λ$CDM model and the spatial curvature…
We investigate the observational constraints on the cosmic neutrino background (CNB) given by the extended $Λ$CDM scenario ($Λ$CDM $+ N_{\rm eff} + \sum m_ν + c^2_{\rm eff} + c^2_{\rm vis} + ξ_ν$) using the latest observational data from \textit{Planck} CMB (temperature power spectrum, low-polarisation and lensing reconstruction), baryon acoustic oscillations (BAOs) , the new recent local value of the Hubble constant from\textit{ Hubble Space Telescope} (\textit{HST}) and information of the abundance of galaxy clusters (GCs). We study the constraints on the CNB background using CMB + BAO + \te…
Probing departures from $Λ$CDM by late-time datasets
Babeș-Bolyai University（博巴伊-波约大学）；Khazar University（哈萨尔大学）；Indian Institute of Astrophysics（印度天体物理研究所）；Università di Napoli “Federico II”（那不勒斯费德里科二世大学）；Istituto Nazionale di Fisica Nucleare (INFN), sez. di Napoli（意大利国家核物理研究所那不勒斯分部）；Scuola Superiore Meridionale（南方高等学院）；Zhejiang Normal University（浙江师范大学）
We examine the validity of the $Λ$CDM model, and probe for the dynamics of dark energy using latest astronomical observations. Using the $Om(z)$ diagnosis, we find that different kinds of observational data are in tension within the $Λ$CDM framework. We then allow for dynamics of dark energy and investigate the constraint on dark energy parameters. We find that for two different kinds of parametrisations of the equation of state parameter $w$, a combination of current data mildly favours an evolving $w$, although the significance is not sufficient for it to be supported by the Bayesian evidenc…
We forecast constraints on cosmological parameters with primary CMB anisotropy information and weak lensing reconstruction with a future post-Planck CMB experiment, the Cosmic Origins Explorer (COrE), using oscillation data on the neutrino mass splittings as prior information. Our MCMC simulations in flat models with a non-evolving equation-of-state of dark energy w give typical 68% upper bounds on the total neutrino mass of 0.136 eV and 0.098 eV for the inverted and normal hierarchies respectively, assuming the total summed mass is close to the minimum allowed by the oscillation data for the …
In the present work, we have adopted a kinematic approach for constraining the extended null diagnostic of concordance cosmology, known as the statefinder hierarchy. A Taylor series expansion of the Hubble parameter has been utilised for the reconstruction. The coefficients of the Taylor series expansion are related to the kinematical parameters like the deceleration parameter, cosmological jerk parameter etc. The present values of the kinematical parameters are constrained from the estimated values of those series coefficients. A Markov chain Monte Carlo analysis has been carried out using th…
We investigate the prospect of constraining scalar field dark energy models using HI 21-cm intensity mapping surveys. We consider a wide class of coupled scalar field dark energy models whose predictions about the background cosmological evolution are different from the $Λ$CDM predictions by a few percent. We find that these models can be statistically distinguished from $Λ$CDM through their imprint on the 21-cm angular power spectrum. At the fiducial $z= 1.5$, corresponding to a radio interferometric observation of the post-reionization HI 21 cm observation at frequency $568 \rm MHz$, these m…
The relic neutrinos are expected to acquire a bulk relative velocity with respect to the dark matter at low redshifts, and neutrino wakes are expected to develop downstream of the dark matter halos. We propose a method of measuring the neutrino mass based on this mechanism. This neutrino wake will cause a dipole distortion of the galaxy-galaxy lensing pattern. This effect could be detected by combining upcoming lensing surveys with a low redshift galaxy survey or a 21 cm intensity mapping survey, which can map the neutrino flow field. The data obtained with LSST and Euclid should enable us to …
Probing dark energy evolution with Quaia quasars through the integrated Sachs-Wolfe effect
MTA–CSFK Lendület “Momentum” Large-Scale Structure (LSS) Research Group（MTA-CSFK 伦杜莱特“动量”大尺度结构研究组）；Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，匈牙利研究与教育网络天文学与地球科学研究中心）；Institute of Physics and Astronomy, ELTE Eötvös Loránd University（罗兰大学物理与天文学研究所）；Institute for Astronomy, University of Hawaii（夏威夷大学天文学研究所）
The cosmological principle states that the Universe is statistically homogeneous and isotropic at large distance scales. There currently exist many observations which indicate a departure from this principle. It has been shown that many of these observations can be explained by invoking superhorizon cosmological perturbations and may be consistent with the Big Bang paradigm. Remarkably, these modes simultaneously explain the observed Hubble tension, i.e., the discrepancy between the direct and indirect measurements of the Hubble parameter. We propose several tests of the cosmological principle…
We apply the Statefinder hierarchy and the growth rate of matter perturbations to discriminate modified Chaplygin gas (MCG), generalized Chaplygin gas (GCG), superfluid Chaplygin gas (SCG), purely kinetic k-essence (PKK), and $Λ$CDM model. We plot the evolutional trajectories of these models in the statefinder plane and in the composite diagnostic plane. We find that GCG, MCG, SCG, PKK, and $Λ$CDM can be distinguished well from each other at the present epoch by using the composite diagnostic $\{ε(z), S^{(1)}_{5}\}$. Using other combinations, such as $\{S^{(1)}_{3}, S^{(1)}_4\}$, $\{S^{(1)}_{3…
Probing dynamical dark energy with late-time data: Evidence, tensions, and the limits of the $w_0w_a$CDM framework
School of Physics and Astronomy, Sun Yat-Sen University（中山大学物理与天文学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Plaksha University（普拉克斯哈大学）；College of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文学与空间科学学院）；Graduate Program in Applied Physics, Federal University of Latin-American Integration（拉丁美洲联邦大学应用物理研究生项目）；Departamento de Engenharias e Ciências Exatas, Universidade Federal do Paraná（巴拉那联邦大学工程与自然科学系）；Department of Physics, Istanbul Technical University（伊斯坦布尔理工大学物理系）
本文通过结合CMB各向异性、DESI DR2、SDSS-IV、横向/角BAO（BAOtr）和Ia型超新星数据，测试$w_0w_a$CDM（CPL）框架与$Λ$CDM的差异，发现CPL推断依赖于数据集，CMB数据单独使用存在几何退化，而DESI DR2 BAO数据推动重建向弱现今加速发展，相比之下，CMB结合PP\&SH0ES和BAOtr更倾向于中等加速膨胀并显著减少哈勃矛盾。这种行为源于低红移距离信息：BAOtr和DESI/SDSS在$z\lesssim0.5$时偏好不同的BAO距离比，驱动了不同的CPL膨胀历史。通过比较角BAO尺度，包括共同的$z=0.510$点和保守的BAOtr局部插值（无外推），量化了这种不匹配。在CPL中，预重组物理固定，$r_{ m d}$几乎不变，因此$H_0$的变化被晚期膨胀自由度吸收而非声学 horizon的变化。贝叶斯证据同样依赖于低红移数据：当PP\&SH0ES和/或BAOtr包含时，它倾向于CPL，对于CMB单独或CMB+DESI是不确定的，而对于CMB+SDSS则略微倾向于$Λ$CDM。这些结果表明，CPL的明显支持及其缓解哈勃矛盾的能力并非普遍，这促使了更灵活的晚期模型和对BAO系统误差的更仔细审查。
Chevallier-Polarski-Linder (CPL) parametrization for the equation of state of dark energy in terms of cosmic redshift or scale factor have been frequently studied in the literature. In this study, we consider cosmic time based CPL parametrization for the equation of state parameter of the effective cosmic fluid that fills the fabric of spatially flat and homogeneous Robertson-Walker spacetime in general relativity. The model exhibits two worthy features: (i) It fits the observational data from the latest $H(z)$ and Union 2.1 SN Ia compilations matching the success of $Λ$CDM model. (ii) It desc…
Probing the Nature of Dark Matter Self-Interactions Through Observations of Massive Black Hole Mergers
Vanderbilt University（范德堡大学）；Fisk University（菲斯克大学）；Flatiron Institute（平顿研究所）；Princeton University（普林斯顿大学）；The Observatories of the Carnegie Institution for Science（卡内基科学促进会天文台）；California Institute of Technology（加州理工学院）
In the curvaton scenario, primordial curvature perturbations are produced by a second field that is sub-dominant during inflation. Depending on how the curvaton decays [possibly producing baryon number, lepton number, or cold dark matter (CDM)], mixtures of correlated isocurvature perturbations are produced, allowing the curvaton scenario to be tested using cosmic microwave background (CMB) data. Here, a full range of 27 curvaton-decay scenarios is compared with CMB data, placing limits on the curvaton fraction at decay, $r_D$, and the lepton asymmetry, $ξ_{\rm lep}$. If baryon number is gener…
Probing the Hubble Tension with an Infinite-Future Condition on the Hubble Parameter
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学天文与前沿科学研究院）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；Department of Astronomy, University of Science and Technology of China（中国科学技术大学天文学系）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文学系）
本文研究了在37个宇宙钟测量数据上对高斯过程（GP）重构H(z)时施加无限未来的条件的影响，结果表明H0值从68.71±6.08降低到约64.67-65.86±4.45-4.85 km s^{-1} Mpc^{-1}，同时H0与Planck ΛCDM值的偏离较小，但与局部距离阶梯测量的偏离增大。
A phenomenological attempt at alleviating the so-called coincidence problem is to allow the dark matter and dark energy to interact. By assuming a coupled quintessence scenario characterized by an interaction parameter $ε$, we investigate the precision in the measurements of the expansion rate $H(z)$ required by future experiments in order to detect a possible deviation from the standard $Λ$CDM model ($ε= 0$). We perform our analyses at two levels, namely: through Monte Carlo simulations based on $ε$CDM models, in which $H(z)$ samples with different accuracies are generated and through an anal…
Dark matter (DM) occupies the majority of matter content in the universe and is probably cold (CDM). However, modifications to the standard CDM model may be required by the small-scale observations, and DM may be self-interacting (SIDM) or warm (WDM). Here we show that the diffractive lensing of gravitational waves (GWs) from binary black hole mergers by small halos ($\sim10^3-10^6M_\odot$; mini-halos) may serve as a clean probe to the nature of DM, free from the contamination of baryonic processes in the DM studies based on dwarf/satellite galaxies. The expected lensed GW signals and event ra…
Considering the mass splittings of three active neutrinos, we investigate how the nature of dark energy affects the cosmological constraints on the total neutrino mass $\sum m_ν$ using the latest cosmological observations. In this paper, some typical dark energy models, including $Λ$CDM, $w$CDM, CPL, and HDE models, are discussed. In the analysis, we also consider the effects from the neutrino mass hierarchies, i.e., the degenerate hierarchy (DH), the normal hierarchy (NH), and the inverted hierarchy (IH). We employ the current cosmological observations to do the analysis, including the Planck…
Combining cosmic microwave background (CMB) data from Planck satellite data, Baryon Acoustic Oscillations (BAO) measurements and Type Ia supernovae (SNe Ia) data, we obtain the bounds on total neutrino masses $M_ν$ with the approximation of degenerate neutrino masses and for three dark energy models: the cosmological constant ($Λ$CDM) model, a phenomenological emergent dark energy (PEDE) model and a model-independent quintessential parameterization (HBK). The bounds on the sum of neutrino masses $M_ν$ depend on the dark energy (DE) models. In the HBK model, we confirm the conclusion from some …
Measuring neutrino mass in light of ACT DR6 and DESI DR2
College of Physical Science and Technology, Shenyang Normal University（沈阳师范大学物理科学与技术学院）；Liaoning Key Laboratory of Cosmology and Astrophysics, College of Sciences, Northeastern University（东北大学理学院）；MOE Key Laboratory of Data Analytics and Optimization for Smart Industry, Northeastern University（东北大学教育部智能制造数据分析与优化重点实验室）；National Frontiers Science Center for Industrial Intelligence and Systems Optimization, Northeastern University（东北大学工业智能与系统优化前沿科学中心）
Models of Dark Matter (DM) can leave unique imprints on the Universe's small scale structure by boosting density perturbations on small scales. We study the capability of Pulsar Timing Arrays to search for, and constrain, subhalos from such models. The models of DM we consider are ordinary adiabatic perturbations in $Λ$CDM, QCD axion miniclusters, models with early matter domination, and vector DM produced during inflation. We show that $Λ$CDM, largely due to tidal stripping effects in the Milky Way, is out of reach for PTAs (as well as every other probe proposed to detect DM small scale struc…
If we assume that we live in the center of a spherical inhomogeneous universe, we can explain the apparent accelerating expansion of the universe without introducing the unknown dark energy or modifying gravitational theory. Direct measurement of the cosmic acceleration can be a powerful tool in distinguishing $Λ$CDM and the inhomogeneous models. If $Λ$CDM is the correct model, we have shown that DECIGO/BBO has sufficient ability to detect the positive redshift drift of the source by observing gravitational waves from neutron star binaries for 5-10 years. This enables us to rule out any Lemaît…
It is well known that flat FRW metric is a special case of Bianchi type I spacetime. In this paper, we use 38 Hubble parameter, $H(z)$, measurements at intermediate redshifts $0.07\leq z\leq 2.36$ and its joint combination with the latest \textgravedbl joint light curves\textacutedbl (JLA) sample, comprised of 740 type Ia supernovae in the redshift range $z ε[0.01, 1.30]$ to constrain the parameters of Bianchi type I dark energy model. We also use the same datasets to constrain flat $Λ$CDM Model. In both cases, we specifically address the expansion rate $H_{0}$ as well as the transition redshi…
Reanalyzing DESI DR1: 4. Percent-Level Cosmological Constraints from Combined Probes and Robust Evidence for the Normal Neutrino Mass Hierarchy
Center for Theoretical Physics – a Leinweber Institute, Massachusetts Institute of Technology（麻省理工学院莱因韦伯理论物理中心）；The NSF AI Institute for Artificial Intelligence and Fundamental Interactions（美国国家科学基金会人工智能基础相互作用研究所）；Department of Physics, Columbia University（哥伦比亚大学物理系）；NASA Hubble Fellowship Program（NASA哈勃奖学金项目）；Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève（日内瓦大学理论物理系与天体粒子物理中心）；Department of Physics, University of California, Berkeley（加州大学伯克利分校物理系）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
A new method to investigate a possible time-dependence of the dark energy equation of state $w$ is proposed. We apply this methodology to two of the most recent data sets of type Ia supernova (Union2 and SDSS) and the baryon acoustic oscillation peak at $z = 0.35$. For some combinations of these data, we show that there is a clear departure from the standard $Λ$CDM model at intermediary redshifts, although a non-evolving dark energy component ($dw/dz = 0$) cannot be ruled out by these data. The approach developed here may be useful to probe a possible evolving dark energy component when applie…
Strong lensing provides a powerful means of investigating the nature of dark matter as it probes dark matter structure on sub-galactic scales. We present an extension of a forward modeling framework that uses flux ratios from quadruply imaged quasars (quads) to measure the shape and amplitude of the halo mass function, including line of sight (LOS) halos and main deflector subhalos. We apply this machinery to 50 mock lenses --- roughly the number of known quads --- with warm dark matter (WDM) mass functions exhibiting free-streaming cutoffs parameterized by the half-mode mass $m_{\rm{hm}}$. As…
Strong gravitational lensing provides a powerful test of Cold Dark Matter (CDM) as it enables the detection and mass measurement of low mass haloes even if they do not contain baryons. Compact lensed sources such as Active Galactic Nuclei (AGN) are particularly sensitive to perturbing subhalos, but their use as a test of CDM has been limited by the small number of systems which have significant radio emission which is extended enough avoid significant lensing by stars in the plane of the lens galaxy, and red enough to be minimally affected by differential dust extinction. Narrow-line emission …
Precision measurements of nature's fundamental couplings and a first measurement of the cosmological redshift drift are two of the key targets for future high-resolution ultra-stable spectrographs such as CODEX. Being able to do both gives CODEX a unique advantage, allowing it to probe dynamical dark energy models (by measuring the behavior of their equation of state) deep in the matter era and thereby testing classes of models that would otherwise be difficult to distinguish from the standard $Λ$CDM paradigm. We illustrate this point with two simple case studies.
We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy (IDE) models. In this study, we focus on two typical interacting dynamical dark energy models, i.e., the interacting $w$ cold dark matter (I$w$CDM) model and the interacting holographic dark energy (IHDE) model. To avoid the large-scale instability problem in IDE models, we apply the parameterized post-Friedmann approach to calculate the perturbation of dark energy. We employ the Planck 2015 cosmic microwave background temperature and polarization data, combined with low-r…
Probing the warm dark matter mass with [C II] intensity mapping
Universität Bonn（波恩大学）；SISSA, International School for Advanced Studies（国际高等研究院）；INAF, Dipartimento di Fisica – Sezione di Astronomia, Università di Trieste（的里雅斯特大学天文物理系）；IFPU, Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；INFN, National Institute for Nuclear Physics of the Universe（国家宇宙核物理研究所）；Laboratoire d’Annecy de Physique Théorique (LAPTh), CNRS/USMB（阿讷西理论物理实验室）；ICSC – Centro Nazionale di Ricerca in High Performance Computing, Big Data and Quantum Computing（高性能计算、大数据与量子计算国家研究中心）；Cardiff Hub for Astrophysics Research and Technology, School of Physics and Astronomy, Cardiff University（卡迪夫大学天体物理学研究与技术中心）
Taking into account the mass splittings between three active neutrinos, we investigate impacts of dark energy on constraining the total neutrino mass $\sum m_ν$ by using recent cosmological observations. We consider two typical dark energy models, namely, the $w$CDM model and the holographic dark energy (HDE) model, which both have an additional free parameter compared with the $Λ$CDM model. We employ the Planck 2015 data of CMB temperature and polarization anisotropies, combined with low-redshift measurements on BAO distance scales, type Ia supernovae, Hubble constant, and Planck lensing. Com…
Quasi-N-body simulations, such as FastPM, provide a fast way to simulate cosmological structure formation, but have yet to adequately include the effects of massive neutrinos. We present a method to include neutrino particles in FastPM, enabling computation of the CDM and total matter power spectra to percent-level accuracy in the non-linear regime. The CDM-neutrino cross-power can also be computed at a sufficient accuracy to constrain cosmological observables. To avoid the shot noise that typically plagues neutrino particle simulations, we employ a quasi-random algorithm to sample the relevan…
In this work, we investigate the constraints on the total neutrino mass in the scenario of vacuum energy interacting with cold dark matter (abbreviated as I$Λ$CDM) by using the latest cosmological observations. We consider four typical interaction forms, i.e., $Q=βH ρ_{\rm de}$, $Q=βH ρ_{\rm c}$, $Q=βH_{0} ρ_{\rm de}$, and $Q=βH_{0} ρ_{\rm c}$, in the I$Λ$CDM scenario. To avoid the large-scale instability problem in interacting dark energy models, we employ the extended parameterized post-Friedmann method for interacting dark energy to calculate the perturbation evolution of dark energy in the…
Cosmic Himalayas in CROCODILE : Probing the Extreme Quasar Overdensities by Count-in-Cells analysis and Nearest Neighbor Distribution
The University of Osaka（大阪大学）；National Astronomical Observatory of Japan（日本国立天文台）；The University of Tokyo（东京大学）；University of Nevada, Las Vegas（内华达大学拉斯维加斯分校）；Zhejiang University（浙江大学）
In this paper, we constrain four time-dependent dark energy (TDDE) models by using the Type Ia supernovae (SNe Ia), baryonic acoustic oscillations (BAO), observational Hubble parameter (OHD) data-sets as well as the single data point from the newest event GW150914. Subsequently, adopting the best fitting values of the model parameters, we apply the original statefinder, statefinder hierarchy, the growth rate of matter perturbations and $Om(z)$ diagnostics to distinguish the TDDE scenarios and the $Λ$CDM scenario from each other. We discover that all the TDDE models and $Λ$CDM model can be dist…
In this paper, we have constrained the neutrino mass and mass hierarchy in the $Λ$CDM cosmology with the neutrino mass hierarchy parameter $Δ$, which represents different mass orderings, by using the {\it Planck} 2015 + BAO + SN + $H_{0}$ data set, together with the neutrino oscillation and neutrinoless double beta decay data. We find that the mass of the lightest neutrinos and the total neutrino mass are no more than $0.035$eV and $0.133$ eV at $95\%$ confidence level, respectively. Comparing the result of our joint analysis with that obtained using cosmological data alone, we find that, by a…
