Journal of Cosmology and Astroparticle Physics最新文献_第5页

Extreme mass ratio inspirals in the cold vector dark matter environment 冷矢量暗物质环境下的极端质量比吸气

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/074

Rajesh Karmakar, Debaprasad Maity and Kaustubh Mukund Vispute

{"title":"Extreme mass ratio inspirals in the cold vector dark matter environment","authors":"Rajesh Karmakar, Debaprasad Maity and Kaustubh Mukund Vispute","doi":"10.1088/1475-7516/2026/07/074","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/07/074","url":null,"abstract":"With regard to the observed dark matter density profiles in galaxies and clusters, the scalar dark matter scenario has been previously studied for its potential detectability through gravitational wave observations at measurable signal-to-noise ratios. In the present study, we consider dark matter described by a massive vector field, also referred to as a Proca field. The density profile in the vicinity of the black hole is explicitly constructed for a broad range of dark matter masses, μ ∼ 10-10-10-15 eV, allowing the dark matter to exhibit both particle and wave-like characteristics. While the computation of the DM density distribution is analytically tractable in the particle regime, we find it convenient to compute the same numerically in the wave regime. Nevertheless, in the outer region, the surrounding dark matter is assumed to follow a broken power-law distribution, represented by a Navarro-Frenk-White (NFW) profile with a central spike. To investigate the detectability of the vector dark matter in the gravitational wave spectrum, we have modelled a stellar-mass black hole (1M⊙) inspiralling into a Schwarzschild black hole of mass 104M⊙ within such a vector dark matter environment. Using this setup, we have analyzed the dephasing in the gravitational wave strain induced by vector dark matter and performed a Fisher forecast for upcoming LISA observations, with particular emphasis on the distinctive features arising in both the particle and wave regimes of the dark matter. Additionally, most of the important results have been compared with the scalar dark matter case.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"54 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148552174","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}

引用次数: 0

Primordial black hole formation in dust-radiation bouncing cosmologies 尘埃辐射弹跳宇宙学中原始黑洞的形成

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/083

Xuan Ye, Luiz Felipe Demétrio, Eduardo José Barroso, Sheng-Feng Yan and Nelson Pinto-Neto

{"title":"Primordial black hole formation in dust-radiation bouncing cosmologies","authors":"Xuan Ye, Luiz Felipe Demétrio, Eduardo José Barroso, Sheng-Feng Yan and Nelson Pinto-Neto","doi":"10.1088/1475-7516/2026/07/083","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/07/083","url":null,"abstract":"Primordial black holes (PBHs) provide a unique probe of the early Universe and may have an enhanced abundance in bouncing cosmologies, where a long contracting phase can amplify perturbations. We develop a unified framework to study PBH formation in dust-radiation bouncing cosmologies, focusing on the classical contracting phase so that the results are insensitive to bounce details. We compute the curvature power spectrum for an extremely small dust equation of state using a stable semi-analytical (adiabatic) method, derive the Jeans length of the two-fluid system using dynamical-system analysis and the WKB approximation, and extend the three-zone model from the single- to the two-fluid case to model local collapse. We implement two collapse criteria to obtain the curvature perturbation threshold for PBH formation and estimate PBH mass fractions for benchmark masses spanning low-mass (10-17M⊙) to supermassive (1013M⊙) scales. The critical curvature threshold is extremely small and nearly mass-independent over a broad range (ζc ∼ 10-21 for 10-14 to 1013M⊙), with deviations only near dust-radiation equality. Nevertheless, the square root of the curvature power spectrum at the relevant formation times is many orders of magnitude smaller, yielding vanishingly small PBH mass fractions across the benchmark masses. Compared with the pure-dust case, radiation pressure and the two-fluid collapse conditions significantly suppress PBH production, implying that substantial PBH formation in dust-radiation bouncing cosmologies would require additional mechanisms to amplify curvature perturbations.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"40 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148552204","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}

引用次数: 0

Numerical simulations of primordial black hole formation via delayed first-order phase transitions 原始黑洞通过延迟一阶相变形成的数值模拟

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/073

Zhuan Ning, Xiang-Xi Zeng, Rong-Gen Cai and Shao-Jiang Wang

{"title":"Numerical simulations of primordial black hole formation via delayed first-order phase transitions","authors":"Zhuan Ning, Xiang-Xi Zeng, Rong-Gen Cai and Shao-Jiang Wang","doi":"10.1088/1475-7516/2026/07/073","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/07/073","url":null,"abstract":"We perform fully nonlinear, spherically symmetric numerical simulations of superhorizon false-vacuum-domain (FVD) collapse in a coupled gravity-scalar-fluid system to study primordial black hole (PBH) formation during delayed first-order phase transitions (FOPTs). Using adaptive mesh refinement to resolve the bubble wall, we identify three dynamical outcomes: type B (supercritical) PBHs with an interior baby universe and a bifurcating trapping horizon, type A (subcritical) PBHs with an apparent horizon formed by direct wall collapse, and dispersal with no PBH formation. To separate these three cases, we evaluate two commonly used PBH-formation criteria: the time scale ratio tH/tV (horizon crossing time versus vacuum-energy domination time) and the local density contrast δ(tH) at horizon crossing. For the parameter space explored, we find that tH/tV is a more robust predictor of outcome: type B PBHs form when tH/tV ≳ 1 (critical range ∼ 1.1 - 1.6 in our survey), type A PBHs arise when tH/tV is below this threshold but remains above a lower bound (typical range ∼ 0.35 - 0.7), and no-PBH dispersal occurs when tH/tV falls below this lower bound. When a clear thin-wall FVD boundary exists, δ(tH) can correspondingly distinguish different outcomes (roughly δc(tH) ∼ 1 - 1.7 for type B and δc(tH) ∼ 0.35 - 0.5 for type A), but is highly sensitive to wall structure and model details and thus less universal. These results offer new insights into the dynamics of FVD collapse, quantify practical PBH-formation thresholds, and pave the way for precise predictions of PBH abundance from delayed FOPTs.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"26 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148552173","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}

引用次数: 0

Spherically-symmetric solutions in quasi-local Einstein-Weyl gravity 准局部Einstein-Weyl引力的球对称解

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/080

Johanna Borissova, Breno L. Giacchini and Aaron Held

引用次数: 0

The role of the galaxy stellar mass function in determining the cosmological distribution of astrophysical transients with applications to fast radio bursts and merging binary black holes 星系恒星质量函数在确定天体物理瞬变的宇宙学分布中的作用及其在快速射电暴和合并双黑洞中的应用

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/072

Sandeep Kumar Acharya

{"title":"The role of the galaxy stellar mass function in determining the cosmological distribution of astrophysical transients with applications to fast radio bursts and merging binary black holes","authors":"Sandeep Kumar Acharya","doi":"10.1088/1475-7516/2026/07/072","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/07/072","url":null,"abstract":"The cosmological distribution and formation rate of compact astrophysical objects such as fast radio bursts (FRBs) are typically assumed to be proportional to a linear combination of cosmological star formation rate and stellar mass. In the literature, a template for star formation rate, which is just a function of redshift, is typically used. In this work, we point out the importance of galaxy stellar mass function which captures the host galaxy information of observed FRBs as well as the redshift evolution of galaxy stellar mass. Using this information and taking the stellar mass distribution of a sample of localized FRBs at face value, we find that FRB formation efficiency per stellar mass may have to be more efficient (by a factor of ≈3) than previously calculated, in order to reproduce the observed volumetric rate of FRBs at z = 0. We show that cosmological population studies of FRBs have to include host galaxy information along with its redshift evolution in order to obtain unbiased results. This consideration is also applicable to other transients, e.g. gamma-ray bursts and merging binary black hole events. We show that our approach may open up the possibility to distinguish between different scenarios of merging binary black holes formation with a detection of few thousand gravitational wave events.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"173 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148552172","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}

引用次数: 0

Nonlinear lattice framework for inflation: Bridging stochastic inflation and the δN formalism 膨胀的非线性晶格框架：桥接随机膨胀和δN形式

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/077

Pankaj Saha, Yuichiro Tada and Yuko Urakawa

{"title":"Nonlinear lattice framework for inflation: Bridging stochastic inflation and the δN formalism","authors":"Pankaj Saha, Yuichiro Tada and Yuko Urakawa","doi":"10.1088/1475-7516/2026/07/077","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/07/077","url":null,"abstract":"Understanding when inflationary perturbations become genuinely nonlinear near the horizon crossing requires methods that go beyond both linear perturbation theory and the gradient expansion. In this work, we introduce a nonlinear lattice framework for single-field inflation based on a shear-free, locally Friedmann–Lemaître–Robertson–Walker geometry. This approach captures the leading effects of inhomogeneous local expansion rates, curvature contributions to the local Friedmann equation, and proper-volume weighting at a fraction of the computational cost of full numerical relativity. We construct fully nonlinear δN observables on uniform-density slices, together with other practical time-dependent estimators for the curvature perturbations. After validating the framework in a standard slow-roll regime, we apply it to Starobinsky's linear-potential model featuring an intermittent ultra-slow-roll phase and a sharp potential transition. During this non-attractor USR regime, the lattice captures the separation of curvature perturbation estimators, the growth and subsequent stabilisation of non-Gaussianity, and a transient weakening of the shear-free approximation when the inflaton velocity becomes very small. Our framework provides a practical intermediate approach between rigid background lattice simulations and full numerical relativity, offering a nonlinear bridge between lattice methods, the δN formalism, and the stochastic inflation formalism as perturbations transition beyond the linear regime.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"57 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148552177","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}

引用次数: 0

Echoes in multi-ALP scenarios 多alp场景下的回声

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/078

Shihabul Haque and Sourov Roy

引用次数: 0

A radiative seesaw in a non-holomorphic modular S 3 flavor symmetry 非全纯模s3风味对称中的辐射跷跷板

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/082

Hiroshi Okada and Yuta Orikasa

引用次数: 0

Sterile neutrino dark matter as a probe of inflationary reheating 无菌中微子暗物质作为暴胀再加热的探测器

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/079

James M. Cline and Yong Xu

引用次数: 0

GWBird: a toolkit for the characterization of the Stochastic Gravitational Wave Background for ground, space, and Pulsar Timing Array detectors GWBird：一个用于表征地面、空间和脉冲星定时阵列探测器的随机引力波背景的工具包

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2026-07-21 DOI: 10.1088/1475-7516/2026/07/076

Ilaria Caporali and Angelo Ricciardone

{"title":"GWBird: a toolkit for the characterization of the Stochastic Gravitational Wave Background for ground, space, and Pulsar Timing Array detectors","authors":"Ilaria Caporali and Angelo Ricciardone","doi":"10.1088/1475-7516/2026/07/076","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/07/076","url":null,"abstract":"The detection of the Stochastic Gravitational Wave Background (SGWB) is one of the most challenging tasks for both current and next-generation detectors. Successfully distinguishing the SGWB from instrumental noise and environmental effects requires accurate and flexible analysis tools capable of detecting the signal and determining its origin. In this paper, we introduce a unified framework and a user-friendly tool for SGWB characterization: GWBird(Gravitational Wave Background Inventory of Response functions for Detectors). This code enables the computation of overlap reduction functions (ORFs), power-law integrated sensitivity curves (PLS), angular response functions, and angular PLS (APLS). It supports the full range of gravitational wave polarization modes (tensor, scalar, and vector), allowing for the characterization of both isotropic and anisotropic SGWB components for all the polarizations. Additionally, the code includes functions for circular polarization characterization, which is particularly relevant for probing parity-violating signals. The framework integrates analyses for ground-based, space-based, and Pulsar Timing Array (PTA) detectors, offering a versatile framework for SGWB analysis. The GWBird code is publicly available at: https://github.com/ilariacaporali/GWBird.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"154 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148552176","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}

引用次数: 0