In this paper we extend the range of consistency of a constant bulk viscosity model to redshifts up to $z\sim 8.1$. In this model the dark sector of the cosmic substratum is a viscous fluid with pressure $p= -ζθ$, where $θ$ is the fluid-expansion scalar and $ζ$ is the coefficient of bulk viscosity. Using the sample of 59 high-redshift GRBs reported by Wei (2010), we calibrate GRBs at low redshifts with the Union 2 sample of SNe Ia, avoiding then the circularity problem. Testing the constant bulk viscosity model with GRBs we found the best fit for the viscosity parameter $\tildeζ$ in the range $0<\tildeζ<3$, being so consistent with previous probes; we also determined the deceleration parameter $q_0$ and the redshift of transition to accelerated expansion. Besides we present an updated analysis of the model with CMB5-year data and CMB7-year data, as well as with the baryon acoustic peak BAO. From the statistics with CMB it turns out that the model does not describe in a feasible way the far far epoch of recombination of the universe, but is in very good concordance for epochs as far as $z\sim 8.1$ till present.
To probe the late evolution history of the Universe, we adopt two kinds of optimal basis systems. One of them is constructed by performing the principle component analysis (PCA) and the other is build by taking the multidimensional scaling (MDS) approach. Cosmological observables such as the luminosity distance can be decomposed into these basis systems. These basis are optimized for different kinds of cosmological models that based on different physical assumptions, even for a mixture model of them. Therefore, the so-called feature space that projected from the basis systems is cosmological m…
We propose that fast radio bursts (FRBs) can be used as the probes to constrain the possible anisotropic distribution of baryon matter in the Universe. Monte Carlo simulations show that, 400 (800) FRBs are enough to detect the anisotropy at 95\% (99\%) confidence level, if the dipole amplitude is at the order of magnitude 0.01. However, much more FRBs are required to tightly constrain the dipole direction. Even 1000 FRBs are far from enough to constrain the dipole direction within angular uncertainty $Δθ<40^{\circ}$ at 95\% confidence level. The uncertainty on the dispersion measure of host ga…
The dispersion measure -- redshift relation of Fast Radio Bursts, $\mathrm{DM}(z)$, has been proposed as a potential new probe of the cosmos, complementary to existing techniques. In practice, however, the effectiveness of this approach depends on a number of factors, including (but not limited to) the intrinsic scatter in the data caused by intervening matter inhomogeneities. Here, we simulate a number of catalogues of mock FRB observations, and use MCMC techniques to forecast constraints, and assess which parameters will likely be best constrained. In all cases we find that any potential imp…
The recently discovered fast radio bursts (FRBs), presumably of extra-galactic origin, have the potential to become a powerful probe of the intergalactic medium (IGM). We point out a few such potential applications. We provide expressions for the dispersion measure and rotation measure as a function of redshift, and we discuss the sensitivity of these measures to the HeII reionization and the IGM magnetic field. Finally we calculate the microlensing effect from an isolate, extragalctic stellar-mass compact object on the FRB spectrum. The time delays between the two lensing images will induce c…
The joint analysis of the Dispersion and Faraday Rotation Measure from distant, polarised Fast Radio Bursts may be used to put constraints on the origin and distribution of extragalactic magnetic fields on cosmological scales. While the combination of Dispersion and Faraday Rotation Measure can in principle give the average magnetic fields along the line-of-sight, in practice this method must be used with care because it strongly depends on the assumed magnetisation model on large cosmological scales. Our simulations show that the observation of Rotation Measures with $\geq 1-10 ~\rm rad/m^2$ …
Fast radio bursts (FRBs) are astrophysical transients of currently unknown origin, and so far several events have been detected at extragalactic distances. The dispersion measure (DM) of the radio signal is a probe of the integrated electron density along the line of sight and therefore allows to map the electron distribution within the large-scale structure. Since a fraction of electrons gets expelled from galaxies by feedback, they are anticorrelated with halos at large scales and hence the angular DM correlations show a scale-dependent bias caused by primordial non-Gaussianity. Although the…
The rapid accumulation of observed Fast Radio Bursts (FRBs) originating from cosmological distances makes it likely that some will be strongly lensed by intervening matter along the line of sight. Detection of lensed FRB repeaters, which account for a noteworthy fraction of the total population, will allow not only an accurate measurement of the lensing time delay, but also follow-up high-resolution observations to pinpoint the location of the lensed images. Recent works proposed to use such strongly-lensed FRBs to derive constraints on the current expansion rate $ H_{0} $ as well as on cosmic…
Emission of relativistic axions from transient sources, such as axion star explosions, can lead to observable signatures. We show that axion bursts from collapsing axion stars can be detectable over the wide range of axion masses $10^{-15} \, \textrm{eV} \lesssim m \lesssim 10^{-7} \, \textrm{eV}$ in laboratory experiments, such as ABRACADABRA, DMRadio and SHAFT. The detection of axion bursts could provide new insights into the fundamental axion potential, which is challenging to probe otherwise. An ensemble of bursts in the distant past would give rise to a diffuse axion background distinct f…
The gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early universe. While hundreds of GRBs are observed by Swift, it remains difficult to determine the intrinsic GRB rate due to the complex trigger algorithm of Swift. Current studies of the GRB rate usually approximate the Swift trigger algorithm by a single detection threshold. However, unlike the previously flown GRB instruments, Swift has over 500 trigger criteria based on …
We investigate the fraction of baryon mass in intergalactic medium ($f_\mathrm{IGM}$), using 18 well-localized FRBs in the redshift range $z\in (0.0039,0.66)$. We construct a five-parameter Bayesian inference model, with the probability distributions of dispersion measures (DM) of IGM and host galaxy properly taken into account. To check the possible redshift evolution, we parameterize $f_\mathrm{IGM}$ as a mildly evolving function of redshift, $f_\mathrm{IGM}=f_\mathrm{IGM,0}[1+αz/(1+z)]$. By simultaneously constraining five parameters, we get $f_\mathrm{IGM,0} = 0.92^{+0.06}_{-0.12}$ and $α=…
Probing Collapsed Dark Matter Halos with Fast Radio Bursts
City University of Hong Kong（香港城市大学）；University of Chinese Academy of Sciences（中国科学院大学）；Tongji University（同济大学）；The Hong Kong University of Science and Technology（香港科技大学）
We use Gamma-ray burst (GRB) spectra total continuum absorption to estimate the key intergalactic medium (IGM) properties of hydrogen column density ($\mathit{N}\textsc{hxigm}$), metallicity, temperature and ionisation parameter over a redshift range of $1.6 \leq z \leq 6.3$, using photo-ionisation (PIE) and collisional ionisation equilibrium (CIE) models for the ionised plasma. We use more realistic host metallicity, dust corrected where available, in generating the host absorption model, assuming that the host intrinsic hydrogen column density is equal to the measured ionisation corrected in…
Long-duration gamma-ray bursts are thought to be associated with the core-collapse of massive, rapidly spinning stars and the formation of black holes. However, efficient angular momentum transport in stellar interiors, currently supported by asteroseismic and gravitational-wave constraints, leads to predominantly slowly-spinning stellar cores. Here, we report on binary stellar evolution and population synthesis calculations, showing that tidal interactions in close binaries not only can explain the observed sub-population of spinning, merging binary black holes but also lead to long gamma-ray…
Boson stars may consist of a new type of light singlet scalar particles with nontrivial self-interactions, and may compose a fraction of the dark matter in the Universe. In this work, we study the dynamics of boson stars with Liouville and logarithmic scalar self-interaction potentials as benchmarks. We perform a numerical analysis as well as a semi-analytic study on how the compactness and the total mass will deviate from that of the usual boson stars formed with a quartic repulsive self-interaction. We apply the recently suggested Swampland conjecture to examine whether boson stars with such…
Probing the Bias of Large-Scale Structure with Unlocalized Fast Radio Bursts
School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天体物理研究所）
Probing Pre-galactic Metal Enrichment with High-Redshift Gamma-Ray Bursts
我们探讨高红移伽马射线暴（GRB）作为有前途的工具，探测前银河系金属富集。利用原始矮星系中爆发的Pop III GRB的明亮余辉作为发光背景源，计算了星系际介质（IGM）中第一重元素留下的金属吸收线的强度。为了得到伽玛射线暴吸收线的诊断，我们使用了一个现有的高分辨率模拟的第一个星系的形成，其特征是在一个维里温度>10^4 K的晕中氢原子冷却的开始。我们探索不寻常的环爆环境内的系统，举办流行III星，模拟密度演化与自相似的解决方案的香槟流。对于接近冷却阈值的微晕，环爆流密度大致与（1+z）成正比，其值约为几cm^{-3}。在质量更大的晕中，对应于第一个星系，密度可能更大，n>100 cm^{-3}。由此产生的余辉通量可以分别在近红外和无线电波段用JWST和VLA检测到，直到红移z>20。我们预测，余辉发射的最大值从近红外到毫米波段移动，峰值通量从mJy到Jy在不同的观测时间。伽玛暴具有高亮度和无特征的幂律谱，是探测IGM早期金属富集的理想工具。由第一颗超新星（SN）爆炸产生的第一个星系中的金属可能处于低电离阶段。我们表明，如果余辉可以观察到足够早，分析的金属线可以区分是否产生的第一个重元素的PISN，或核心塌陷（II型）SN，从而约束的初始质量函数的第一个恒星。
Planck stars form when a collapsing shell of matter within a black hole reaches the Planck density, roughly equivalent to the mass being compressed into a volumetric size near that of the proton, and rebounds outwards. These planck stars have been considered as accounting for both fast radio bursts and short gamma ray bursts, whilst offering a comparatively low energy perspective onto quantum gravity. The observation of such an event would require black hole masses much smaller than a solar mass, which could be provided by primordial black hole dark matter models. We discuss the low energy iso…
The Optically Unbiased Gamma-Ray Burst Host (TOUGH) Survey. VII. The Host Galaxy Luminosity Function: Probing the Relationship Between GRBs and Star Formation to Redshift $\sim6$
Probing Cosmic Curvature with Fast Radio Bursts and DESI DR2
Universidade Federal do Espírito Santo (UFES)（埃斯皮里托圣托联邦大学）；Instituto Argentino de Radioastronomía（阿根廷射电天文研究所）；University of Cape Town（开普敦大学）；Universidad Nacional de La Plata（拉普拉塔国立大学）
For future surveys of fast radio bursts (FRBs), we clarify information available from cosmic dispersion measures (DMs) through cross-correlation analyses of foreground dark matter haloes (hosting galaxies and galaxy clusters) with their known redshifts. With a halo-model approach, we predict that the cross-correlation with cluster-sized haloes is less affected by the details of gastrophysics, providing robust cosmological information. For less massive haloes, the cross-correlation at angular scales of $<10\, \mathrm{arcmin}$ is sensitive to gas expelled from the halo centre due to galactic fee…
Probing Evolution of Long Gamma-Ray Burst Properties through Their Cosmic Formation History
Clemson University（克莱姆森大学）；National Astronomical Observatory of Japan（日本国立天文台）；The Graduate University for Advanced Studies, SOKENDAI（综合研究大学院大学）；Space Science Institute（空间科学研究所）；University of Nevada, Las Vegas（内华达大学拉斯维加斯分校）；Bay Environmental Institute（湾环境研究所）；Jagiellonian University（雅盖隆大学）；Astronomical Observatory of Jagiellonian University（雅盖隆大学天文台）
Probing the Cosmic Web with Fast Radio Bursts. I. Scattering
Racah Institute of Physics, The Hebrew University（拉卡物理研究所，希伯来大学）；Astrophysics Research Center of the Open University (ARCO), The Open University of Israel（开放大学天体物理研究中心（ARCO），以色列开放大学）；Department of Natural Sciences, The Open University of Israel（自然科学系，以色列开放大学）；Department of Physics, The George Washington University（物理系，乔治华盛顿大学）；Department of Physics, University of California, Santa Barbara（物理系，加州大学圣塔芭芭拉分校）
Probing the Cosmic Baryon Distribution and the Impact of Active Galactic Nuclei Feedback with Fast Radio Bursts in CROCODILE Simulation
The University of Osaka（大阪大学）；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）；Seoul National University（首尔大学）
We show that the Platinum gamma-ray burst (GRB) data compilation, probing the redshift range $0.553 \leq z \leq 5.0$, obeys a cosmological-model-independent three-parameter fundamental plane (Dainotti) correlation and so is standardizable. While they probe the largely unexplored $z \sim 2.3-5$ part of cosmological redshift space, the GRB cosmological parameter constraints are consistent with, but less precise than, those from a combination of baryon acoustic oscillation (BAO) and Hubble parameter [$H(z)$] data. In order to increase the precision of GRB-only cosmological constraints, we exclude…
Probing the Baryon Distribution with Fast Radio Bursts
The University of Sydney（悉尼大学）；University of Cape Town（开普敦大学）；African Institute for Mathematical Sciences（非洲数学科学研究所）；Curtin University（科廷大学）；Swinburne University of Technology（斯威本科技大学）；ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav)（引力波发现卓越研究中心 (OzGrav)）；Stanford University（斯坦福大学）；Trinity College Dublin（都柏林三一学院）；Stellenbosch University（斯坦陵布什大学）；Aix-Marseille University（艾克斯-马赛大学）；Australian National University（澳大利亚国立大学）；Indian Institute of Technology, Indore（印度理工学院印多尔分校）；Chinese Academy of Sciences（中国科学院）；University of Chinese Academy of Sciences（中国科学院大学）
Probing the cosmic web with fast radio bursts: II. Scintillation
Racah Institute of Physics, The Hebrew University（拉卡物理研究所，希伯来大学）；University of Washington, Department of Astronomy（华盛顿大学天文学系）；Astrophysics Research Center of the Open University (ARCO), The Open University of Israel（开放大学天体物理学研究中心（ARCO），以色列开放大学）；Department of Natural Sciences, The Open University of Israel（自然科学与系，以色列开放大学）；Department of Physics, The George Washington University（乔治华盛顿大学物理系）；Department of Physics, University of California, Santa Barbara（加州大学圣塔芭芭拉分校物理系）
