Journal of Cosmology and Astroparticle Physics最新文献_第7页

Constraints on ultra-slow-roll inflation with the NANOGrav 15-Year dataset

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-29 DOI: 10.1088/1475-7516/2024/11/065

Bo Mu, Jing Liu, Gong Cheng and Zong-Kuan Guo

{"title":"Constraints on ultra-slow-roll inflation with the NANOGrav 15-Year dataset","authors":"Bo Mu, Jing Liu, Gong Cheng and Zong-Kuan Guo","doi":"10.1088/1475-7516/2024/11/065","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/065","url":null,"abstract":"Ultra-slow-roll (USR) inflation predicts an exponential amplification of scalar perturbations at small scales, which leads to a stochastic gravitational wave background (SGWB) through the coupling of the scalar and tensor modes at the second-order expansion of the Einstein equation. In this work, we search for such a scalar-induced SGWB from the NANOGrav 15-year (NG15) dataset, and find that the SGWB from USR inflation could explain the observed data. The Bayes factors are 54 ± 5 for the USR inflation model alone and 68 ± 6 for the combined USR inflation plus supermassive black hole binaries (SMBHB) models. We place constraints on the amplitude of the scalar power spectrum to PRp > 10-1.95 at 95% confidence level (C.L.) at the scale of k ∼ 20 pc-1. We find that log10PRp degenerates with the peak scale log10kp. We also obtain the parameter space allowed by the data in the USR inflationary scenario, where the e-folding numbers of the duration of the USR phase has a lower limit ΔN > 2.80 (95% C.L.) when the USR phase ends at N ≈ 20. With astrophysically motivated priors, the NG15 dataset fits both the USR inflation model and SMBHB model equally well.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"10 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753260","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

Dilaton generation in propagation of magnetic dipole waves of pulsar in a galactic magnetic field

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-29 DOI: 10.1088/1475-7516/2024/11/066

M.O. Astashenkov, A.V. Bedda, K.V. Parfenov and P.A. Vshivtseva

{"title":"Dilaton generation in propagation of magnetic dipole waves of pulsar in a galactic magnetic field","authors":"M.O. Astashenkov, A.V. Bedda, K.V. Parfenov and P.A. Vshivtseva","doi":"10.1088/1475-7516/2024/11/066","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/066","url":null,"abstract":"This study is devoted to dilaton generation during the propagation of magnetic dipole waves from a pulsar in the galactic magnetic field. Dilaton generation occurs at cosmological scales on the order of the coherence lengths of the galactic magnetic field Lcoh, approximately 100 pc. The exact solutions of the dilaton field equation in a vacuum and in the interstellar medium with reflective index n = 1 + χ, χ ≪ 1 have been obtained, and the angular distribution of emitted dilaton energy has been determined in both cases. It has been shown that the dilaton generation intensity at first increases proportionally to r2, where r is distance from the neutron star to the observation point, then has oscillating behavior. The obtained results are applicable only for r < Lcoh. For a millisecond pulsar with a magnetic field BS ∼ 109 Gauss, located at a distance from Earth on the order of the coherence length of the galactic magnetic field Lcoh ∼ 100 pc, the obtained intensity of the dilaton generation can be greater in 100 times than the analogous intensity produced by rotating magnetic dipole momentum of a pulsar. Based on estimated values, the impact of pulsar and magnetar gravitational fields on magnetic dipole wave radiation is minimal and changes the amplitude of the waves by around 1 percent. For this reason, the effect of the gravitational field on the dilaton formation process can be disregarded in this study.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"115 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753071","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

Hunting nonstandard neutrino interactions and leptoquarks in dark matter experiments

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-29 DOI: 10.1088/1475-7516/2024/11/068

Thomas Schwemberger, Volodymyr Takhistov and Tien-Tien Yu

引用次数: 0

Inflation with vector fields revisited: heavy entropy perturbations and primordial black holes

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-28 DOI: 10.1088/1475-7516/2024/11/063

Chong-Bin Chen

引用次数: 0

Towards unveiling the large-scale nature of gravity with the wavelet scattering transform

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-28 DOI: 10.1088/1475-7516/2024/11/061

Georgios Valogiannis, Francisco Villaescusa-Navarro and Marco Baldi

{"title":"Towards unveiling the large-scale nature of gravity with the wavelet scattering transform","authors":"Georgios Valogiannis, Francisco Villaescusa-Navarro and Marco Baldi","doi":"10.1088/1475-7516/2024/11/061","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/061","url":null,"abstract":"We present the first application of the Wavelet Scattering Transform (WST) in order to constrain the nature of gravity using the three-dimensional (3D) large-scale structure of the universe. Utilizing the Quijote-MG N-body simulations, we can reliably model the 3D matter overdensity field for the f(R) Hu-Sawicki modified gravity (MG) model down to kmax = 0.5 h/Mpc. Combining these simulations with the QuijoteνCDM collection, we then conduct a Fisher forecast of the marginalized constraints obtained on gravity using the WST coefficients and the matter power spectrum at redshift z=0. Our results demonstrate that the WST substantially improves upon the 1σ error obtained on the parameter that captures deviations from standard General Relativity (GR), yielding a tenfold improvement compared to the corresponding matter power spectrum result. At the same time, the WST also enhances the precision on the ΛCDM parameters and the sum of neutrino masses, by factors of 1.2-3.4 compared to the matter power spectrum, respectively. Despite the overall reduction in the WST performance when we focus on larger scales, it still provides a relatively 4.5× tighter 1σ error for the MG parameter at kmax =0.2 h/Mpc, highlighting its great sensitivity to the underlying gravity theory. This first proof-of-concept study reaffirms the constraining properties of the WST technique and paves the way for exciting future applications in order to perform precise large-scale tests of gravity with the new generation of cutting-edge cosmological data.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"69 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753073","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

Measuring the speed of light with cosmological observations: current constraints and forecasts

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-28 DOI: 10.1088/1475-7516/2024/11/062

Jaiane Santos, Carlos Bengaly, Jonathan Morais and Rodrigo S. Gonçalves

引用次数: 0

Coport: a new public code for polarized radiative transfer in a covariant framework Coport：协变框架下的偏振辐射传递新公共代码

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-27 DOI: 10.1088/1475-7516/2024/11/054

Jiewei Huang, Liheng Zheng, Minyong Guo and Bin Chen

{"title":"Coport: a new public code for polarized radiative transfer in a covariant framework","authors":"Jiewei Huang, Liheng Zheng, Minyong Guo and Bin Chen","doi":"10.1088/1475-7516/2024/11/054","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/054","url":null,"abstract":"General relativistic radiative transfer calculations are essential for comparing theoretical models of black hole accretion flows and jets with observational data. In this work, we introduce Coport,[The public version of Coport is available at the following URL: https://github.com/JieweiHuang/Coport.] a novel public code specifically designed for covariant polarized ray-tracing radiative transfer computations in any spacetime. Written in Julia, Coport includes an interface for visualizing numerical results obtained from HARM, a publicly available implementation of the general relativistic magnetohydrodynamics code. We validate the precision of our code by comparing its outputs with the results from a variety of established methodologies. This includes the verification against analytical solutions, the validation through thin-disk assessments, and the evaluation via thick-disk analyses. Notably, our code employs a methodology that eliminates the need for separating the computations of spacetime propagation and plasma propagation. Instead, it directly solves the coupled, covariant, polarized radiative transfer equation in curved spacetime, seamlessly integrating the effects of gravity with plasma influences. This approach sets our code apart from the existing alternatives and enhances its accuracy and efficiency.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"2 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718370","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

K-mouflage at high k: extending the reach of Hi-COLA 高 K 值下的 K 值伪装：扩大 Hi-COLA 的覆盖范围

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-27 DOI: 10.1088/1475-7516/2024/11/052

Ashim Sen Gupta, Bartolomeo Fiorini and Tessa Baker

引用次数: 0

Fast likelihood-free inference in the LSS Stage IV era LSS 第 IV 阶段时代的快速无似然推理

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-27 DOI: 10.1088/1475-7516/2024/11/057

Guillermo Franco-Abellán, Guadalupe Cañas-Herrera, Matteo Martinelli, Oleg Savchenko, Davide Sciotti and Christoph Weniger

{"title":"Fast likelihood-free inference in the LSS Stage IV era","authors":"Guillermo Franco-Abellán, Guadalupe Cañas-Herrera, Matteo Martinelli, Oleg Savchenko, Davide Sciotti and Christoph Weniger","doi":"10.1088/1475-7516/2024/11/057","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/057","url":null,"abstract":"Forthcoming large-scale structure (LSS) Stage IV surveys will provide us with unprecedented data to probe the nature of dark matter and dark energy. However, analysing these data with conventional Markov Chain Monte Carlo (MCMC) methods will be challenging, due to the increase in the number of nuisance parameters and the presence of intractable likelihoods. In light of this, we present the first application of Marginal Neural Ratio Estimation (MNRE) (a recent approach in simulation-based inference) to LSS photometric probes: weak lensing, galaxy clustering and the cross-correlation power spectra. In order to analyse the hundreds of spectra simultaneously, we find that a pre-compression of data using principal component analysis, as well as parameter-specific data summaries lead to highly accurate results. Using expected Stage IV experimental noise, we are able to recover the posterior distribution for the cosmological parameters with a speedup factor of ∼ 10-60 compared to classical MCMC methods. To illustrate that the performance of MNRE is not impeded when posteriors are significantly non-Gaussian, we test a scenario of two-body decaying dark matter, finding that Stage IV surveys can improve current bounds on the model by up to one order of magnitude. This result supports that MNRE is a powerful framework to constrain the standard cosmological model and its extensions with next-generation LSS surveys.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"25 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718372","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

Neutrino quantum kinetics in two spatial dimensions 两个空间维度的中微子量子动力学

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2024-11-27 DOI: 10.1088/1475-7516/2024/11/060

Marie Cornelius, Shashank Shalgar and Irene Tamborra

{"title":"Neutrino quantum kinetics in two spatial dimensions","authors":"Marie Cornelius, Shashank Shalgar and Irene Tamborra","doi":"10.1088/1475-7516/2024/11/060","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/060","url":null,"abstract":"Our understanding of neutrino flavor conversion in the innermost regions of core-collapse supernovae and neutron star mergers is mostly limited to spherically symmetric configurations that facilitate the numerical solution of the quantum kinetic equations. In this paper, we simulate neutrino quantum kinetics within a (2+1+1) dimensional setup: we model the flavor evolution during neutrino decoupling from matter in two spatial dimensions, one neutrino momentum variable, and time; taking into account non-forward neutral current and charged current collisions of neutrinos with the matter background, as well as neutrino advection. In order to mimic fluctuations in the neutrino emission and matter background, and explore their effect on the flavor evolution, we introduce perturbations in the collision term as well as in the vacuum term of the Hamiltonian. Because of such perturbations, the initial symmetry of the neutrino field across the simulation annulus is broken and flavor conversion is qualitatively affected, with regions of larger flavor conversion alternating across the simulation annulus. In addition, neutrino advection is responsible for spreading flavor waves across neighboring spatial regions. Although based on a simplified setup, our findings highlight the importance of modeling neutrino quantum kinetics in multi-dimensions to assess the impact of neutrinos on the physics of compact astrophysical sources and nucleosynthesis.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"8 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718374","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