Pub Date : 2024-10-17DOI: 10.1088/1475-7516/2024/10/063
Tiago M. Crispim, Milko Estrada, C.R. Muniz and G. Alencar
We provide a way for embedding a 4-dimensional geometry corresponding to the Simpson-Visser (SV) spacetime — which is capable of representing a traversable wormhole, a one-way wormhole, or a regular black hole — into a Randall-Sundrum setup. To achieve this, we linearly deform the bulk geometry and the bulk matter distribution concerning a coupling constant. These deformations induce a transition from a 5D vacuum AdS state to an anisotropic matter distribution. The latter results in the induced geometry on the brane transitioning from a singular Schwarzschild spacetime to a regularized SV spacetime. Since there are no sources or matter fields on the brane, we can assert that the induced SV geometry on the brane arises from the influence of geometrical and matter deformations in the bulk. Thus, the central singularity is suppressed. We determine the cases where the energy conditions are either satisfied or violated. Our spacetime is asymptotically radial AdS, which is intriguing given the absence of a global AdS box that would prevent instability under larger wavelength perturbations. Therefore, it is no longer appropriate to claim that instability exists for very small perturbations near the AdS horizon. Thus, we propose that the stability of the solution can be analyzed by examining the speed of sound due to the presence of matter fields in the energy momentum tensor.
{"title":"Braneworld black bounce to transversable wormhole","authors":"Tiago M. Crispim, Milko Estrada, C.R. Muniz and G. Alencar","doi":"10.1088/1475-7516/2024/10/063","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/063","url":null,"abstract":"We provide a way for embedding a 4-dimensional geometry corresponding to the Simpson-Visser (SV) spacetime — which is capable of representing a traversable wormhole, a one-way wormhole, or a regular black hole — into a Randall-Sundrum setup. To achieve this, we linearly deform the bulk geometry and the bulk matter distribution concerning a coupling constant. These deformations induce a transition from a 5D vacuum AdS state to an anisotropic matter distribution. The latter results in the induced geometry on the brane transitioning from a singular Schwarzschild spacetime to a regularized SV spacetime. Since there are no sources or matter fields on the brane, we can assert that the induced SV geometry on the brane arises from the influence of geometrical and matter deformations in the bulk. Thus, the central singularity is suppressed. We determine the cases where the energy conditions are either satisfied or violated. Our spacetime is asymptotically radial AdS, which is intriguing given the absence of a global AdS box that would prevent instability under larger wavelength perturbations. Therefore, it is no longer appropriate to claim that instability exists for very small perturbations near the AdS horizon. Thus, we propose that the stability of the solution can be analyzed by examining the speed of sound due to the presence of matter fields in the energy momentum tensor.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"31 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-17DOI: 10.1088/1475-7516/2024/10/065
Basabendu Barman, Kousik Loho and Óscar Zapata
We investigate the implications of memory burden on the gravitational wave (GW) spectrum arising from the Hawking evaporation of light primordial black holes (PBHs). By considering both rotating (Kerr) and non-rotating (Schwarzschild) PBHs, we demonstrate that the overproduction of primordial GWs from burdened PBHs could impose stringent constraints on the parameters governing backreaction effects. These constraints, derived from ΔNeff measurements by Planck and prospective experiments such as CMB-S4 and CMB-HD, offer novel insights into the impact of memory burden on PBH dynamics.
{"title":"Constraining burdened PBHs with gravitational waves","authors":"Basabendu Barman, Kousik Loho and Óscar Zapata","doi":"10.1088/1475-7516/2024/10/065","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/065","url":null,"abstract":"We investigate the implications of memory burden on the gravitational wave (GW) spectrum arising from the Hawking evaporation of light primordial black holes (PBHs). By considering both rotating (Kerr) and non-rotating (Schwarzschild) PBHs, we demonstrate that the overproduction of primordial GWs from burdened PBHs could impose stringent constraints on the parameters governing backreaction effects. These constraints, derived from ΔNeff measurements by Planck and prospective experiments such as CMB-S4 and CMB-HD, offer novel insights into the impact of memory burden on PBH dynamics.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"17 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1088/1475-7516/2024/10/060
Teppei Okumura and Misao Sasaki
Gravitational waves (GWs) may be produced by various mechanisms in the early universe. In particular, if parity is violated, it may lead to the production of parity-violating GWs. In this paper, we focus on GWs on the scale of the large-scale structure. Since GWs induce tidal deformations of the shape of galaxies, one can extract such GW signals by observing images of galaxies in galaxy surveys. Conventionally the detection of such signals is discussed by considering the three-dimensional power spectra of the E/B-modes. Here, we develop a complementary new technique to estimate the contribution of GWs to the tidal force tensor field projected on the celestial sphere, which is a directly observable quantity. We introduce two two-dimensional vector fields constructed by taking the divergence and curl of the projected tidal field in three dimensions. Their auto-correlation functions naturally contain contributions of the scalar-type tidal field. However, we find that the divergence of the curl of the projected tidal field, which is a pseudo-scalar quantity, is free from the scalar contribution and thus enables us to extract GW signals. We also find that we can detect parity-violating signals in the GWs by observing the nonzero cross-correlation between the divergence of the projected tidal field and the curl of it. It roughly corresponds to measuring the cross-power spectrum of E and B-modes, but these are complementary to each other in the sense that our estimator can be naturally defined locally in position space. Finally we present expressions of the correlation functions in the form of Fourier integrals, and discuss the properties of the kernels specific to the GW case, which we call the overlap reduction function, borrowing the terminology used in the pulsar timing array experiments.
引力波（GWs）可能是由早期宇宙中的各种机制产生的。特别是，如果违反了奇偶性，就可能产生违反奇偶性的引力波。本文重点研究大尺度结构尺度上的 GWs。由于GW会引起星系形状的潮汐变形，因此我们可以通过星系巡天观测中的星系图像来提取这种GW信号。传统的方法是通过考虑 E/B 模式的三维功率谱来讨论这种信号的探测。在这里，我们开发了一种互补的新技术，来估算全球风暴对投影在天球上的潮汐力张量场的贡献，这是一个可以直接观测到的量。我们引入了两个二维矢量场，它们由三维投影潮汐场的发散和卷曲构成。它们的自相关函数自然包含标量型潮汐场的贡献。然而，我们发现投影潮汐场的卷曲发散是一个伪标量，它不包含标量贡献，因此我们能够提取出全球风暴信号。我们还发现，通过观察投影潮汐场的发散和它的卷曲之间的非零交叉相关性，我们可以探测到全球风暴中违反奇偶性的信号。这大致相当于测量 E 模和 B 模的交叉功率谱，但它们是互补的，因为我们的估计器可以自然地在位置空间局部定义。最后，我们以傅里叶积分的形式给出了相关函数的表达式，并讨论了 GW 情况下特有的核的特性，我们借用脉冲星定时阵列实验中的术语，将其称为重叠减少函数。
{"title":"Extracting parity-violating gravitational waves from projected tidal force tensor in three dimensions","authors":"Teppei Okumura and Misao Sasaki","doi":"10.1088/1475-7516/2024/10/060","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/060","url":null,"abstract":"Gravitational waves (GWs) may be produced by various mechanisms in the early universe. In particular, if parity is violated, it may lead to the production of parity-violating GWs. In this paper, we focus on GWs on the scale of the large-scale structure. Since GWs induce tidal deformations of the shape of galaxies, one can extract such GW signals by observing images of galaxies in galaxy surveys. Conventionally the detection of such signals is discussed by considering the three-dimensional power spectra of the E/B-modes. Here, we develop a complementary new technique to estimate the contribution of GWs to the tidal force tensor field projected on the celestial sphere, which is a directly observable quantity. We introduce two two-dimensional vector fields constructed by taking the divergence and curl of the projected tidal field in three dimensions. Their auto-correlation functions naturally contain contributions of the scalar-type tidal field. However, we find that the divergence of the curl of the projected tidal field, which is a pseudo-scalar quantity, is free from the scalar contribution and thus enables us to extract GW signals. We also find that we can detect parity-violating signals in the GWs by observing the nonzero cross-correlation between the divergence of the projected tidal field and the curl of it. It roughly corresponds to measuring the cross-power spectrum of E and B-modes, but these are complementary to each other in the sense that our estimator can be naturally defined locally in position space. Finally we present expressions of the correlation functions in the form of Fourier integrals, and discuss the properties of the kernels specific to the GW case, which we call the overlap reduction function, borrowing the terminology used in the pulsar timing array experiments.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"73 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1088/1475-7516/2024/10/059
Hamsa Padmanabhan and Abraham Loeb
The James Webb Space Telescope (JWST) recently reported a large population of UV luminous galaxies at high redshifts, z > 10, as well as Lyman-α emitting (LAE) galaxies out to z ∼ 11. We use the observed UV luminosities along with a data-driven approach at lower redshifts to place constraints on the observability of the intergalactic Lyman-α intensity, scattered in the form of Loeb-Rybicki haloes, during the pre-reionization and reionization epochs (z ∼ 9-16). We forecast the sensitivity and resolution required to detect these intergalactic haloes, finding that individual haloes with LAE luminosities > 1043 ergs/s are detectable at a few sigma level at z ≲ 9, while stacking of ∼ 10 haloes is expected to result in detections out to z ∼ 16. Finding these haloes is expected to shed light on the neutral intergalactic hydrogen during cosmic reionization.
{"title":"Intergalactic Lyman-α haloes before reionization are detectable with JWST","authors":"Hamsa Padmanabhan and Abraham Loeb","doi":"10.1088/1475-7516/2024/10/059","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/059","url":null,"abstract":"The James Webb Space Telescope (JWST) recently reported a large population of UV luminous galaxies at high redshifts, z > 10, as well as Lyman-α emitting (LAE) galaxies out to z ∼ 11. We use the observed UV luminosities along with a data-driven approach at lower redshifts to place constraints on the observability of the intergalactic Lyman-α intensity, scattered in the form of Loeb-Rybicki haloes, during the pre-reionization and reionization epochs (z ∼ 9-16). We forecast the sensitivity and resolution required to detect these intergalactic haloes, finding that individual haloes with LAE luminosities > 1043 ergs/s are detectable at a few sigma level at z ≲ 9, while stacking of ∼ 10 haloes is expected to result in detections out to z ∼ 16. Finding these haloes is expected to shed light on the neutral intergalactic hydrogen during cosmic reionization.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"18 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1088/1475-7516/2024/10/061
Gregorio Carullo
Closed-form expressions for the ringdown complex amplitudes of nonspinning unequal-mass binaries in arbitrarily eccentric orbits are presented. They are built upon 237 numerical simulations contained within the RIT catalog, through the parameterisation introduced in [Phys. Rev. Lett.132 (2024) 101401]. Global fits for the complex amplitudes, associated to linear quasinormal mode frequencies of the dominant ringdown modes, are obtained in a factorised form immediately applicable to any existing quasi-circular model. Similarly to merger amplitudes, ringdown ones increase by more than 50% compared to the circular case for high impact parameters (medium eccentricities), while strongly suppressed in the low impact parameter (highly eccentric) limit. Such reduction can be explained by a transition between an “orbital-type” and an “infall-type” dynamics. The amplitudes (phases) fits accuracy lies around a few percent (deciradians) for the majority of the dataset, comparable to the accuracy of current state-of-the-art quasi-circular ringdown models, and well within current statistical errors of current LIGO-Virgo-Kagra ringdown observations. These expressions constitute another building block towards the construction of complete general relativistic inspiral-merger-ringdown semi-analytical templates, and allow to extend numerically-informed spectroscopic analyses beyond the circular limit. Such generalisations are key to achieve accurate inference of compact binaries astrophysical properties, and tame astrophysical systematics within observational investigations of strong-field general relativistic dynamics.
{"title":"Ringdown amplitudes of nonspinning eccentric binaries","authors":"Gregorio Carullo","doi":"10.1088/1475-7516/2024/10/061","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/061","url":null,"abstract":"Closed-form expressions for the ringdown complex amplitudes of nonspinning unequal-mass binaries in arbitrarily eccentric orbits are presented. They are built upon 237 numerical simulations contained within the RIT catalog, through the parameterisation introduced in [Phys. Rev. Lett.132 (2024) 101401]. Global fits for the complex amplitudes, associated to linear quasinormal mode frequencies of the dominant ringdown modes, are obtained in a factorised form immediately applicable to any existing quasi-circular model. Similarly to merger amplitudes, ringdown ones increase by more than 50% compared to the circular case for high impact parameters (medium eccentricities), while strongly suppressed in the low impact parameter (highly eccentric) limit. Such reduction can be explained by a transition between an “orbital-type” and an “infall-type” dynamics. The amplitudes (phases) fits accuracy lies around a few percent (deciradians) for the majority of the dataset, comparable to the accuracy of current state-of-the-art quasi-circular ringdown models, and well within current statistical errors of current LIGO-Virgo-Kagra ringdown observations. These expressions constitute another building block towards the construction of complete general relativistic inspiral-merger-ringdown semi-analytical templates, and allow to extend numerically-informed spectroscopic analyses beyond the circular limit. Such generalisations are key to achieve accurate inference of compact binaries astrophysical properties, and tame astrophysical systematics within observational investigations of strong-field general relativistic dynamics.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"11 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1088/1475-7516/2024/10/056
Yunlong Liu and Xiangdong Zhang
In this paper, we calculate the frequencies of geodesic orbits in self-dual spacetime on the equatorial plane and obtain the leading-order effects of loop quantum parameters P on the energy flux and angular momentum flux in eccentric extreme mass ratio inspirals. The gravitational waveform under different eccentricity is carried out by improved “analytic-kludge” method. We calculate the waveform mismatches for the LISA detector and the measurement error on loop quantum parameters. The constraint capability on P will be improved by a factor of 3 to 10, compared to the weak field experiments in the solar system.
本文计算了赤道面自偶时空中大地轨道的频率，并得到了环量子参数P对偏心极质量比吸气中能量通量和角动量通量的先导效应。采用改进的 "解析-克鲁吉 "方法，对不同偏心率下的引力波形进行了计算。我们计算了 LISA 探测器的波形失配和环量子参数的测量误差。与太阳系的弱场实验相比，对 P 的约束能力将提高 3 到 10 倍。
{"title":"Gravitational waves for eccentric extreme mass ratio inspirals of self-dual spacetime","authors":"Yunlong Liu and Xiangdong Zhang","doi":"10.1088/1475-7516/2024/10/056","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/056","url":null,"abstract":"In this paper, we calculate the frequencies of geodesic orbits in self-dual spacetime on the equatorial plane and obtain the leading-order effects of loop quantum parameters P on the energy flux and angular momentum flux in eccentric extreme mass ratio inspirals. The gravitational waveform under different eccentricity is carried out by improved “analytic-kludge” method. We calculate the waveform mismatches for the LISA detector and the measurement error on loop quantum parameters. The constraint capability on P will be improved by a factor of 3 to 10, compared to the weak field experiments in the solar system.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"10 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1088/1475-7516/2024/10/058
Umang Kumar and Suratna Das
A thorough MCMC analysis of any inflationary model against the current cosmological data is essential for assessing the validity of such a model as a viable inflationary model. Warm Inflation, producing both thermal and quantum fluctuations, yield a complex form of scalar power spectrum, which, in general, cannot be directly written as a function of the comoving wavenumber k, an essential step to incorporate the primordial spectra into CAMB to do an MCMC analysis through CosmoMC/Cobaya. In this paper, we devised an efficient generalized methodology to mould the WI power spectra as a function of k, without the need of slow-roll approximation of the inflationary dynamics. The methodology is directly applicable to any Warm Inflation model, including the ones with complex forms of the dissipative coefficient and the inflaton potential.
根据当前的宇宙学数据对任何膨胀模型进行全面的 MCMC 分析，对于评估该模型作为可行的膨胀模型的有效性至关重要。暖膨胀同时产生热波动和量子波动，产生了复杂形式的标量功率谱，一般来说，它不能直接写成移动波数 k 的函数，这是通过 CosmoMC/Cobaya 将原始谱纳入 CAMB 进行 MCMC 分析的必要步骤。在本文中，我们设计了一种高效的通用方法来模塑作为 k 函数的 WI 功率谱，而不需要对膨胀动力学进行慢滚近似。该方法直接适用于任何暖膨胀模型，包括耗散系数和膨胀势形式复杂的模型。
{"title":"A generalized method of constraining Warm Inflation with CMB data","authors":"Umang Kumar and Suratna Das","doi":"10.1088/1475-7516/2024/10/058","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/058","url":null,"abstract":"A thorough MCMC analysis of any inflationary model against the current cosmological data is essential for assessing the validity of such a model as a viable inflationary model. Warm Inflation, producing both thermal and quantum fluctuations, yield a complex form of scalar power spectrum, which, in general, cannot be directly written as a function of the comoving wavenumber k, an essential step to incorporate the primordial spectra into CAMB to do an MCMC analysis through CosmoMC/Cobaya. In this paper, we devised an efficient generalized methodology to mould the WI power spectra as a function of k, without the need of slow-roll approximation of the inflationary dynamics. The methodology is directly applicable to any Warm Inflation model, including the ones with complex forms of the dissipative coefficient and the inflaton potential.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"6 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1088/1475-7516/2024/10/057
Ryuichi Takahashi
The cosmological dispersion measure (DM) as a function of redshift, derived from localized fast radio bursts (FRBs), has been used as a tool for constraining the cosmic ionized fraction and cosmological parameters. For these purposes, the DM in a homogeneous cosmological model has typically been used, neglecting the inhomogeneity of matter distribution. In this study, we derive a bias in the ensemble average of the DM over many FRBs owing to gravitational lensing by the inhomogeneous matter distribution based on cosmological perturbation theory. We demonstrate that the ensemble average is 0.4 %–1 % smaller than the DM in the corresponding homogeneous model for a source redshift of zs=1, according to recent cosmological hydrodynamic simulations of IllustrisTNG and BAHAMAS. This reduction occurs because light rays from FRBs tend to avoid high-density regions owing to lensing deflection. We also discuss another selection effect, magnification bias, where demagnified FRBs with low DMs, fainter than the detection threshold, are excluded from the observed sample, leading to a selective observation of magnified FRBs with high DMs. Lensing bias, including magnification bias, must be considered to achieve percent level accuracy in the DM-redshift relation.
{"title":"Impact of lensing bias on the cosmological dispersion measure","authors":"Ryuichi Takahashi","doi":"10.1088/1475-7516/2024/10/057","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/057","url":null,"abstract":"The cosmological dispersion measure (DM) as a function of redshift, derived from localized fast radio bursts (FRBs), has been used as a tool for constraining the cosmic ionized fraction and cosmological parameters. For these purposes, the DM in a homogeneous cosmological model has typically been used, neglecting the inhomogeneity of matter distribution. In this study, we derive a bias in the ensemble average of the DM over many FRBs owing to gravitational lensing by the inhomogeneous matter distribution based on cosmological perturbation theory. We demonstrate that the ensemble average is 0.4 %–1 % smaller than the DM in the corresponding homogeneous model for a source redshift of zs=1, according to recent cosmological hydrodynamic simulations of IllustrisTNG and BAHAMAS. This reduction occurs because light rays from FRBs tend to avoid high-density regions owing to lensing deflection. We also discuss another selection effect, magnification bias, where demagnified FRBs with low DMs, fainter than the detection threshold, are excluded from the observed sample, leading to a selective observation of magnified FRBs with high DMs. Lensing bias, including magnification bias, must be considered to achieve percent level accuracy in the DM-redshift relation.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1088/1475-7516/2024/10/049
Pierre Auclair, Baptiste Blachier and Christophe Ringeval
Making observable predictions for cosmic inflation requires determining when the wavenumbers of astrophysical interest today exited the Hubble radius during the inflationary epoch. These instants are commonly evaluated using the slow-roll approximation and measured in e-folds Δ N=N - Nend, in reference to the e-fold Nend at which inflation ended. Slow roll being necessarily violated towards the end of inflation, both the approximated trajectory and Nend are determined at, typically, one or two e-folds precision. Up to now, such an uncertainty has been innocuous, but this will no longer be the case with the forthcoming cosmological measurements. In this work, we introduce a new and simple analytical method, on top of the usual slow-roll approximation, that reduces uncertainties on ΔN to less than a tenth of an e-fold.
{"title":"Clocking the end of cosmic inflation","authors":"Pierre Auclair, Baptiste Blachier and Christophe Ringeval","doi":"10.1088/1475-7516/2024/10/049","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/049","url":null,"abstract":"Making observable predictions for cosmic inflation requires determining when the wavenumbers of astrophysical interest today exited the Hubble radius during the inflationary epoch. These instants are commonly evaluated using the slow-roll approximation and measured in e-folds Δ N=N - Nend, in reference to the e-fold Nend at which inflation ended. Slow roll being necessarily violated towards the end of inflation, both the approximated trajectory and Nend are determined at, typically, one or two e-folds precision. Up to now, such an uncertainty has been innocuous, but this will no longer be the case with the forthcoming cosmological measurements. In this work, we introduce a new and simple analytical method, on top of the usual slow-roll approximation, that reduces uncertainties on ΔN to less than a tenth of an e-fold.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"6 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1088/1475-7516/2024/10/048
R. Calderon, K. Lodha, A. Shafieloo, E. Linder, W. Sohn, A. de Mattia, J.L. Cervantes-Cota, R. Crittenden, T.M. Davis, M. Ishak, A.G. Kim, W. Matthewson, G. Niz, S. Park, J. Aguilar, S. Ahlen, S. Allen, D. Brooks, T. Claybaugh, A. de la Macorra, A. Dey, B. Dey, P. Doel, J.E. Forero-Romero, E. Gaztañaga, S.Gontcho A. Gontcho, K. Honscheid, C. Howlett, S. Juneau, A. Kremin, M. Landriau, L. Le Guillou, M.E. Levi, M. Manera, R. Miquel, J. Moustakas, J.A. Newman, N. Palanque-Delabrouille, W.J. Percival, C. Poppett, F. Prada, M. Rezaie, G. Rossi, V. Ruhlmann-Kleider, E. Sanchez, D. Schlegel, M. Schubnell, H. Seo, D. Sprayberry, G. Tarlé, P. Taylor, M. Vargas-Magaña, B.A. Weaver, P. Zarrouk and H. Zou
We implement Crossing Statistics to reconstruct in a model-agnostic manner the expansion history of the universe and properties of dark energy, using DESI Data Release 1 (DR1) BAO data in combination with one of three different supernova compilations (PantheonPlus, Union3, and DES-SN5YR) and Planck CMB observations. Our results hint towards an evolving and emergent dark energy behaviour, with negligible presence of dark energy at z ≳ 1, at varying significance depending on data sets combined. In all these reconstructions, the cosmological constant lies outside the 95% confidence intervals for some redshift ranges. This dark energy behaviour, reconstructed using Crossing Statistics, is in agreement with results from the conventionalw0–wa dark energy equation of state parametrization reported in the DESI Key cosmology paper. Our results add an extensive class of model-agnostic reconstructions with acceptable fits to the data, including models where cosmic acceleration slows down at low redshifts. We also report constraints on H0rd from our model-agnostic analysis, independent of the pre-recombination physics.
我们利用 DESI Data Release 1 (DR1) BAO 数据，结合三种不同的超新星汇编（PantheonPlus、Union3 和 DES-SN5YR）之一和普朗克 CMB 观测数据，实施了 "交叉统计"（Crossing Statistics），以与模型无关的方式重建了宇宙的膨胀历史和暗能量的特性。我们的研究结果表明，暗能量行为是不断演变和出现的，在 z ≳ 1 时暗能量的存在可以忽略不计，其重要程度因数据集的组合而异。在所有这些重建中，宇宙学常数在某些红移范围内处于95%置信区间之外。利用交叉统计重建的这种暗能量行为，与DESI关键宇宙学论文中报告的常规w0-wa暗能量状态方程参数化的结果是一致的。我们的结果增加了一大类与数据拟合度可接受的与模型无关的重建，包括宇宙加速度在低红移时减慢的模型。我们还报告了与模型无关的分析对 H0rd 的约束，与重组前物理学无关。
{"title":"DESI 2024: reconstructing dark energy using crossing statistics with DESI DR1 BAO data","authors":"R. Calderon, K. Lodha, A. Shafieloo, E. Linder, W. Sohn, A. de Mattia, J.L. Cervantes-Cota, R. Crittenden, T.M. Davis, M. Ishak, A.G. Kim, W. Matthewson, G. Niz, S. Park, J. Aguilar, S. Ahlen, S. Allen, D. Brooks, T. Claybaugh, A. de la Macorra, A. Dey, B. Dey, P. Doel, J.E. Forero-Romero, E. Gaztañaga, S.Gontcho A. Gontcho, K. Honscheid, C. Howlett, S. Juneau, A. Kremin, M. Landriau, L. Le Guillou, M.E. Levi, M. Manera, R. Miquel, J. Moustakas, J.A. Newman, N. Palanque-Delabrouille, W.J. Percival, C. Poppett, F. Prada, M. Rezaie, G. Rossi, V. Ruhlmann-Kleider, E. Sanchez, D. Schlegel, M. Schubnell, H. Seo, D. Sprayberry, G. Tarlé, P. Taylor, M. Vargas-Magaña, B.A. Weaver, P. Zarrouk and H. Zou","doi":"10.1088/1475-7516/2024/10/048","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/10/048","url":null,"abstract":"We implement Crossing Statistics to reconstruct in a model-agnostic manner the expansion history of the universe and properties of dark energy, using DESI Data Release 1 (DR1) BAO data in combination with one of three different supernova compilations (PantheonPlus, Union3, and DES-SN5YR) and Planck CMB observations. Our results hint towards an evolving and emergent dark energy behaviour, with negligible presence of dark energy at z ≳ 1, at varying significance depending on data sets combined. In all these reconstructions, the cosmological constant lies outside the 95% confidence intervals for some redshift ranges. This dark energy behaviour, reconstructed using Crossing Statistics, is in agreement with results from the conventionalw0–wa dark energy equation of state parametrization reported in the DESI Key cosmology paper. Our results add an extensive class of model-agnostic reconstructions with acceptable fits to the data, including models where cosmic acceleration slows down at low redshifts. We also report constraints on H0rd from our model-agnostic analysis, independent of the pre-recombination physics.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"11 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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