Journal of Cosmology and Astroparticle Physics最新文献_第8页

The observation image of a soliton boson star illuminated by various accretions 被各种吸积所照亮的孤子玻色子星的观测图像

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-30 DOI: 10.1088/1475-7516/2025/10/003

Ke-Jian He, Guo-Ping Li, Chen-Yu Yang and Xiao-Xiong Zeng

{"title":"The observation image of a soliton boson star illuminated by various accretions","authors":"Ke-Jian He, Guo-Ping Li, Chen-Yu Yang and Xiao-Xiong Zeng","doi":"10.1088/1475-7516/2025/10/003","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/003","url":null,"abstract":"In this paper, we explore the observable signatures of solitonic boson stars by employing ray-tracing simulations, with celestial spheres and thin accretion disks serving as illumination sources. By numerically fitting the metric form, we solve the geodesic equation for photons under the influence of the soliton potential, enabling us to simulate the optical appearance of the soliton boson star in two distinct regimes. In the weak coupling case (larger value of coupling parameter α) with an initial scalar field ψ0, the images on the screen predominantly show direct and lensed images, where ψ0 and α modulate the image region size while the observation inclination θ controls morphological asymmetry. In the case of strong coupling (small value of α), the images on the screen show a nested sub-annulus within the Einstein ring in the celestial model, whereas thin disk accretion models reveal higher-order lensing images indicative that photons are capable of orbiting the equatorial plane of the boson star multiple times. We also analyze how the effective potential and redshift factor depend on the correlation parameter. At low inclination(θ < 30°), the redshift is the dominant effect, the image is characterized by a dim central cavity enclosed by a bright ring. At high inclination (θ > 60°), the Doppler effect becomes more pronounced, resulting in a substantial brightness disparity between the left and right sides of the optical image. These findings offer robust theoretical underpinnings for differentiating solitonic boson stars from black holes via high-resolution astronomical observations.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"21 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145195483","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

Dark matter annihilation from pulsating dark stars 暗物质从脉动的暗恒星中湮灭

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-30 DOI: 10.1088/1475-7516/2025/10/001

Chris Kouvaris and Dimitris Zavitsanos

引用次数: 0

Robust evidence for dynamical dark energy from DESI galaxy-CMB lensing cross-correlation and geometric probes 来自DESI星系- cmb透镜相互关联和几何探测器的动态暗能量的有力证据

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-29 DOI: 10.1088/1475-7516/2025/09/084

Miguel A. Sabogal and Rafael C. Nunes

{"title":"Robust evidence for dynamical dark energy from DESI galaxy-CMB lensing cross-correlation and geometric probes","authors":"Miguel A. Sabogal and Rafael C. Nunes","doi":"10.1088/1475-7516/2025/09/084","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/084","url":null,"abstract":"Recent analyses joining data from the Cosmic Microwave Background (CMB), Baryon Acoustic Oscillations (BAO), and Type Ia Supernovae (SNIa) have provided strong evidence in favor of dynamical dark energy (DDE) over a simple cosmological constant. Motivated by these findings, we present new observational constraints on DDE based on the cross-correlation between DESI Luminous Red Galaxies (LRG) samples and CMB lensing (CMBκ × LRG), which effectively probes the impact of cosmological parameters on the growth of structure at the perturbative level. We demonstrate that, when combined with geometric measurements such as BAO and SNIa, this cross-correlation yields compelling statistical evidence for DDE exceeding 4σ, including within simpler parametrizations such as the wCDM model. Remarkably, this evidence is independent of constraints from primary Planck CMB anisotropies data. These results highlight the robustness and potential of Galaxy-CMB lensing cross-correlation as a powerful observational probe of the dark sector, particularly when used in conjunction with geometric observables.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"114 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188676","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

Free cosmic density bispectrum on small scales 小尺度上的自由宇宙密度双谱

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-29 DOI: 10.1088/1475-7516/2025/09/083

Ricardo Waibel, Sara Konrad and Matthias Bartelmann

{"title":"Free cosmic density bispectrum on small scales","authors":"Ricardo Waibel, Sara Konrad and Matthias Bartelmann","doi":"10.1088/1475-7516/2025/09/083","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/083","url":null,"abstract":"We study the asymptotic behaviour of the free, cold-dark matter density fluctuation bispectrum in the limit of small scales. From an initially Gaussian random field, we draw phase-space positions of test particles which then propagate along Zel'dovich trajectories. Only initial momentum-momentum correlation are considered, making the formulas identical to the typical Zel'dovich approximation. A suitable expansion of the initial momentum auto-correlations of these particles leads to an asymptotic series whose lower-order power-law exponents we calculate. The dominant contribution has an exponent of -11/2. For triangle configurations with zero surface area, this exponent is even enhanced to -9/2. These power laws can only be revealed by a non-perturbative calculation with respect to the initial power spectrum. They are valid for a general class of initial power spectra with a cut-off function, required to enforce convergence of its moments. We then confirm our analytic results numerically. Finally, we use this asymptotic behaviour to investigate the shape dependence of the bispectrum in the small-scale limit, and to show how different shapes grow over cosmic time. These confirm the usual model of gravitational collapse within the Zel'dovich picture.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"327 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188681","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

Testing the consistency of new Amati-correlated gamma-ray burst dataset cosmological constraints with those from better-established cosmological data 测试新的阿玛蒂相关伽玛暴数据集宇宙学约束与更成熟的宇宙学数据的一致性

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-28 DOI: 10.1088/1475-7516/2025/09/081

Shulei Cao and Bharat Ratra

{"title":"Testing the consistency of new Amati-correlated gamma-ray burst dataset cosmological constraints with those from better-established cosmological data","authors":"Shulei Cao and Bharat Ratra","doi":"10.1088/1475-7516/2025/09/081","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/081","url":null,"abstract":"Gamma-ray bursts (GRBs) are promising cosmological probes for exploring the Universe at intermediate redshifts (z). We analyze 151 Fermi-observed long GRBs (datasets A123 and A28) to simultaneously constrain the Amati correlation and cosmological parameters within six spatially flat and nonflat dark energy models. We find that these datasets are standardizable via a single Amati correlation, suggesting their potential for cosmological analyses. However, constraints on the current value of the nonrelativistic matter density parameter from A123 and the combined A123 + A28 data exhibit > 2σ tension with those derived from a joint analysis of better-established Hubble parameter [H(z)] and baryon acoustic oscillation (BAO) data for most considered cosmological models. This tension indicates that these GRB data are unsuitable for jointly constraining cosmological parameters with better-established H(z) + BAO and similar data. Although the A28 data constraints are consistent with the H(z) + BAO data constraints, its limited sample size (28 GRBs) and high intrinsic scatter (∼0.7) diminishes its statistical power compared to existing datasets.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"92 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188678","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

Increase of ns in regularized pole inflation & Einstein-Cartan gravity 正则极膨胀中ns的增加&爱因斯坦-卡坦引力

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-28 DOI: 10.1088/1475-7516/2025/09/080

Minxi He, Muzi Hong and Kyohei Mukaida

{"title":"Increase of ns in regularized pole inflation & Einstein-Cartan gravity","authors":"Minxi He, Muzi Hong and Kyohei Mukaida","doi":"10.1088/1475-7516/2025/09/080","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/080","url":null,"abstract":"We show that the regularization of the second order pole in the pole inflation can induce the increase of ns, which may be important after the latest data release of cosmic microwave background (CMB) observation by Atacama Cosmology Telescope (ACT). Pole inflation is known to provide a unified description of attractor models that they can generate a flat plateau for inflation given a general potential. Recent ACT observation suggests that the constraint on the scalar spectral index ns at CMB scale may be shifted to a larger value than the predictions in the Starobinsky model, the Higgs inflation, and the α-attractor model, which motivates us to consider the modification of the pole inflation. We find that if we regularize the second order pole in the kinetic term such that the kinetic term becomes regular for all field range, we can generally increase n_s because the potential in the large field regime will be lifted. We have explicitly demonstrated that this type of regularized pole inflation can naturally arise from the Einstein-Cartan formalism, and the inflationary predictions are consistent with the latest ACT data without spoiling the success of the α-attractor models.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"31 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188682","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

PQ-ball and its real scalar analogue in an expanding universe 在膨胀的宇宙中pq球和它的真实标量模拟

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-28 DOI: 10.1088/1475-7516/2025/09/082

Kazunori Nakayama and Masaki Yamada

引用次数: 0

Cosmic curl — features and convergence of the vorticity power spectrum in N-body simulations 宇宙旋度——n体模拟中涡度功率谱的特征和收敛

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-28 DOI: 10.1088/1475-7516/2025/09/079

Camilla T.G. Sørensen, Steen Hannestad and Thomas Tram

{"title":"Cosmic curl — features and convergence of the vorticity power spectrum in N-body simulations","authors":"Camilla T.G. Sørensen, Steen Hannestad and Thomas Tram","doi":"10.1088/1475-7516/2025/09/079","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/079","url":null,"abstract":"Observations of the cosmic velocity field could become an important cosmological probe in the near future. To take advantage of future velocity-flow surveys we must however have the theoretical predictions under control. In many respects, the velocity field is easier to simulate than the density field because it is less severely affected by small-scale clustering. Therefore, as we also show in this paper, a particle-mesh (PM) based simulation approach is usually sufficient, yielding results within a few percent of a corresponding P3M simulation in which short-range forces are properly accounted for, but which also carry a much larger computational cost. However, in other respects the velocity field is much more challenging to deal with than the density field: interpolating the velocity field onto a grid is significantly more complicated, and the vorticity field (the curl-part of the velocity field) is severely affected by both sample variance and discretisation effects. While the former can be dealt with using fixed amplitude initial conditions, the former makes it infeasible to run fully converged simulations in a cosmological volume. However, using the N-body code we show that one can robustly extrapolate the cosmic vorticity power spectrum from just 4 simulations with different number of particles. We expect our extrapolated vorticity power spectra to be correct within 5% of the fully converged result across three orders of magnitude in k. Finally, we have also investigated the time dependence of the vorticity as well as the ratio of vorticity to divergence.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"20 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188755","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

Improved cosmological limits on Z' models with light right-handed neutrinos 用轻右手中微子改进Z模型的宇宙学极限

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-28 DOI: 10.1088/1475-7516/2025/09/078

Tim Herbermann and Manfred Lindner

{"title":"Improved cosmological limits on Z' models with light right-handed neutrinos","authors":"Tim Herbermann and Manfred Lindner","doi":"10.1088/1475-7516/2025/09/078","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/078","url":null,"abstract":"We improve limits on extensions of the Standard Model (SM) with light right-handed neutrinos. The presence of shared gauge interactions between the light right-handed neutrinos and other SM fermions allows for production of νR in the early Universe and we use the excess in the effective number of neutrino species ΔNeff to place limits. Our benchmark model is a minimal gauged U(1)B-L that often arises as a building block in other models, and we discuss applicability to more general U(1) extensions. We devise an improved Monte Carlo integration scheme convenient for implementation of generic integrated Boltzmann equations with minimal simplifying assumptions. We sketch our numerical implementation in detail for future reference. Using the new ACT DR6 limit ΔNeff < 0.17, we improve constraints on the gauge coupling for 1 GeV < mZ' < 100 TeV by orders of magnitude and find the strongest limits thus far, surpassing even current and future colliders, and explore the potential of future CMB experiments to test U(1) extensions up to the GUT scale. We perform a detailed analysis of the robustness of cosmological limits within standard and non-standard thermal histories and find that a strong first order phase transition, early dark energy or early matter domination could dilute νR abundances beyond detection. We investigate the effect of reheating on νR-genesis and provide results and prescriptions to apply our bounds to non-standard thermal histories. Limits are generically weakened for reheating Treh ≪ mZ'. Our results suggest that projected limits on Z' with Dirac neutrinos can only be accommodated for in non-standard thermal histories, thus limiting the options to include dark matter candidates or Dirac leptogenesis.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"19 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188677","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 correlators from multi-point propagators 来自多点传播器的原始相关器

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-09-25 DOI: 10.1088/1475-7516/2025/09/077

Andrea Costantini, Laura Iacconi and David J. Mulryne

{"title":"Primordial correlators from multi-point propagators","authors":"Andrea Costantini, Laura Iacconi and David J. Mulryne","doi":"10.1088/1475-7516/2025/09/077","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/077","url":null,"abstract":"A key step in the comparison between inflationary predictions and cosmological observations is the computation of primordial correlators. Numerical methods have been developed that overcome some of the difficulties arising in analytical calculations when the models considered are complex. The PyTransport package, which implements the transport formalism, allows computation of the tree-level 2- and 3-point correlation functions for multi-field models with arbitrary potentials and a curved field space. In this work we investigate an alternative numerical implementation of the transport approach, based on the use of transfer “matrices” called multi-point propagators (MPP). We test the novel MPP method, and extensively compare it with the traditional implementation of the transport approach provided in PyTransport. We highlight advantages of the former, discussing its performance in terms of accuracy, precision and running time, as well as dependence on the number of e-folds of sub-horizon evolution and tolerance settings. For topical ultra-slow-roll models of inflation we show that MPPs (i) precisely track the decay of correlators even when PyTransport produces erroneous results, (ii) extend the computation of squeezed bispectra for squeezing values at least one decade beyond those attainable with PyTransport.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"18 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141378","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