Journal of Cosmology and Astroparticle Physics最新文献

Application of graph networks to a wide-field water-Cherenkov-based Gamma-ray Observatory

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-26 DOI: 10.1088/1475-7516/2025/02/066

J. Glombitza, M. Schneider, F. Leitl, S. Funk and C. van Eldik

引用次数: 0

Asymmetric warm dark matter: from cosmological asymmetry to chirality of life

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-26 DOI: 10.1088/1475-7516/2025/02/063

Wen Yin, Shota Nakagawa, Tamaki Murokoshi and Makoto Hattori

引用次数: 0

Galactic gas models strongly affect the determination of the diffusive halo height

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-26 DOI: 10.1088/1475-7516/2025/02/062

Pedro De La Torre Luque and Tim Linden

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Numerical analysis of melting domain walls and their gravitational waves

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-26 DOI: 10.1088/1475-7516/2025/02/064

I. Dankovsky, S. Ramazanov, E. Babichev, D. Gorbunov and A. Vikman

{"title":"Numerical analysis of melting domain walls and their gravitational waves","authors":"I. Dankovsky, S. Ramazanov, E. Babichev, D. Gorbunov and A. Vikman","doi":"10.1088/1475-7516/2025/02/064","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/02/064","url":null,"abstract":"We study domain walls (DWs) arising in field theories where Z2-symmetry is spontaneously broken by a scalar expectation value decreasing proportionally to the Universe temperature. The energy density of such melting DWs redshifts sufficiently fast not to overclose the Universe. For the first time, evolution of melting DWs and the resulting gravitational waves (GWs) is investigated numerically using lattice simulations. We show that formation of closed melting DWs during radiation domination is much more efficient compared to the scenario with constant tension DWs. This suggests that it can be the main mechanism responsible for reaching the scaling regime similarly to the case of cosmic strings. However, the scaling behaviour of melting DWs is observed, provided only that the initial scalar field fluctuations are not very large. Otherwise, simulations reveal violation of the scaling law, potentially of the non-physical origin. The spectrum of GWs emitted by melting DWs is also significantly different from that of constant tension DWs. Whether the system has reached scaling or not, the numerical study reveals a GW spectrum described in the infrared by the spectral index n ≈ 1.6 followed by the causality tail. We attribute the difference from the value n = 2 predicted in our previous studies to a finite lifetime of the DW network. Notably, the updated index is still in excellent agreement with the recent findings by pulsar timing arrays, which confirms that melting DWs can be responsible for the observed (GW) signal. We also point out that results for evolution of melting DWs in the radiation-dominated Universe are applicable to constant tension DW evolution in the flat spacetime.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"83 1 Pt 2 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495172","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

Imprints of black hole charge on the precessing jet nozzle of M87*

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-26 DOI: 10.1088/1475-7516/2025/02/065

Xiang-Cheng Meng, Chao-Hui Wang and Shao-Wen Wei

{"title":"Imprints of black hole charge on the precessing jet nozzle of M87*","authors":"Xiang-Cheng Meng, Chao-Hui Wang and Shao-Wen Wei","doi":"10.1088/1475-7516/2025/02/065","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/02/065","url":null,"abstract":"The observed jet precession period of approximately 11 years for M87* strongly suggests the presence of a supermassive rotating black hole with a tilted accretion disk at the center of the galaxy. By modeling the motion of the tilted accretion disk particle with the spherical orbits around a Kerr-Newman black hole, we study the effect of charge on the observation of the precession period, thereby exploring the potential of this strong-gravity observation in constraining multiple black hole parameters. First, using the Hamiltonian formalism, we derive the equations of motion for spherical orbits, along with the general forms of energy and angular momentum, in the general stationary axisymmetric black hole spacetime. Subsequently, taking the Kerr-Newman black hole as a specific example, we study the effect of charge on spherical orbits and find that the precession period increases with increasing charge. Furthermore, incorporating the constraints of EHT on the black hole charge, we utilize the observed M87* jet precession period to constrain the relationship between the spin, charge, and warp radius, specifically detailing the correlations between each pair of these three quantities. To further refine constraints on the charge, we explore the negative correlation between the maximum warp radius and charge. A significant result shows that the gap between the maximum warp radius of the prograde and retrograde disk decrease with the black hole charge. If the warp radius is provided by other observations, different constraints on the charge can be derived for the prograde and retrograde cases. Finally, we investigate the size of the inner disk. By making use of current observations, our study reveals that the size of the inner disk increases with the charge and spin, and the prograde disk is always larger than the retrograde one. These results provide significant effects of charge in the physics around M87*.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"24 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495173","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

Apparent horizons in cosmologically-embedded black holes

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-25 DOI: 10.1088/1475-7516/2025/02/051

Mariano Cadoni, Mirko Pitzalis and Andrea P. Sanna

引用次数: 0

Gravitational effects on fluid dynamics in cosmological first-order phase transitions

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-25 DOI: 10.1088/1475-7516/2025/02/057

Ryusuke Jinno and Jun'ya Kume

引用次数: 0

Non-locality in quadrupolar gravitational radiation

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-25 DOI: 10.1088/1475-7516/2025/02/049

S. Capozziello, M. Capriolo, A. Carleo and G. Lambiase

{"title":"Non-locality in quadrupolar gravitational radiation","authors":"S. Capozziello, M. Capriolo, A. Carleo and G. Lambiase","doi":"10.1088/1475-7516/2025/02/049","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/02/049","url":null,"abstract":"General Relativity suffers for two main problems which have not yet been overcome: it predicts spacetime singularities and cannot be formulated as a perturbative renormalizable theory. In particular, many attempts have been made for avoiding singularities, such as considering higher order or infinite derivative theories. The price to pay in both cases is to give up locality and therefore they are known altogether as non-local theories of gravity. In this paper, we investigate how to recognize the presence of non-local effects by exploiting the power emitted by gravitational waves in a binary system in presence of non-local corrections as R□-1R to the Hilbert-Einstein action. After solving the field equations in terms of the source stress-energy tensor Tμν and obtaining the gravitational wave stress-energy pseudo-tensor, Tμν, we find that the General Relativity quadrupole formula is modified in a non-trivial way, making it feasible to find a possible signature of non-locality. Our final results on the gravitational wave stress-energy pseudo-tensor could also be applied to several astrophysical scenarios involving energy or momentum loss, potentially providing multiple tests for non-local deviations from General Relativity. We finally discuss the detectability of the massless transverse scalar mode, discovering that, although this radiation is extremely weak, in a small range around the model divergence, its amplitude could fall within the low-frequency Einstein Telescope sensitivity.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"27 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143485840","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

Asymmetries from a charged memory-burdened PBH

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-25 DOI: 10.1088/1475-7516/2025/02/052

Basabendu Barman, Kousik Loho and Óscar Zapata

引用次数: 0

The haloes that reionized the Universe

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-02-25 DOI: 10.1088/1475-7516/2025/02/061

Nachiket Joshi and Mahavir Sharma

{"title":"The haloes that reionized the Universe","authors":"Nachiket Joshi and Mahavir Sharma","doi":"10.1088/1475-7516/2025/02/061","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/02/061","url":null,"abstract":"We study the reionization of the Universe due to haloes that host galaxies undergoing bursts of star formation. By comparing the recent results from the James Webb Space Telescope (JWST) with the cosmological hydrodynamical simulation eagle at z ≥ 6, we find that bursty galaxies have specific star formation rate, sSFR > 10-2 Myr-1, and magnitude, MUV ≤ -17. Most of them reside in haloes of mass ∼ 109 M⊙ and some in more massive haloes. We then construct the models of escape fraction and find that a skewed Gaussian function with a flat tail towards the high mass end best describes the mean dependence of escape fraction on halo mass, considering the haloes hosting bursty galaxies as the primary drivers of reionization. We implement the models of escape fraction in the code 21cmfast to study the progress of reionization and derive the evolution of the mean ionized fraction that agrees well with observations. We also calculate the brightness temperature, spin temperature, and kinetic temperature and further study the spatial fluctuations in these quantities to gain insights into the progress of reionization. We compute the 21 cm power spectrum and predict a peak in power at 180 MHz corresponding to redshift, z ≈ 6.8, that is testable by the upcoming Square Kilometre Array (SKA). Our findings suggest that the Universe was reionized by the haloes of ≳ 109 M⊙.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"65 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143485834","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