Journal of Cosmology and Astroparticle Physics最新文献

Spacetime surgery for black hole fireworks 黑洞烟花的时空手术

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-23 DOI: 10.1088/1475-7516/2025/01/098

Wei-Chen Lin, Dong-han Yeom and Dejan Stojkovic

{"title":"Spacetime surgery for black hole fireworks","authors":"Wei-Chen Lin, Dong-han Yeom and Dejan Stojkovic","doi":"10.1088/1475-7516/2025/01/098","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/098","url":null,"abstract":"We construct an explicit model for the black hole to white hole transition (known as the black hole fireworks scenario) using the cut-and-paste technique. We model a black hole collapse using the evolution of a time-like shell in the background of the loop quantum gravity inspired metric and then the space-like shell analysis to construct the firework geometry. Our simple and well-defined analysis removes some subtle issues that were present in the previous literature [1] and makes the examination of the junction conditions easier. We further point out that the infalling and asymptotic observers, both in ours and the original scenario in ref. [1], encounter quite different physics. While the proper time of the bounce for an infalling observer can be determined without ambiguity, the bouncing time interval for the asymptotic observer can be chosen arbitrarily by changing how one cuts and pastes the spacetimes outside the event horizons. It is puzzling that the proper time of a distant (rather than infalling) observer is subject to randomness since the infalling observer is supposed to experience a stronger quantum gravity effect. This result might suggest that a black hole firework scenario does not allow for the existence of an effectively classical spacetime inside the horizon. The main message is therefore that even if we strictly follow the thin shell formalism to cut and paste spacetimes, this does not guarantee that the resulting spacetime offers a physically reasonable background.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"12 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020571","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

Distinct photon-ALP propagation modes 不同的光子- alp传播模式

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-23 DOI: 10.1088/1475-7516/2025/01/099

Qing-Hong Cao, Zuowei Liu and Jun-Chen Wang

引用次数: 0

Ultra slow-roll with a black hole 超慢滚黑洞

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-22 DOI: 10.1088/1475-7516/2025/01/096

Lewis Croney, Ruth Gregory and Sam Patrick

引用次数: 0

ANNZ+: an enhanced photometric redshift estimation algorithm with applications on the PAU survey ANNZ+：一种增强的光度红移估计算法及其在PAU巡天中的应用

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-22 DOI: 10.1088/1475-7516/2025/01/097

Imdad Mahmud Pathi, John Y.H. Soo, Mao Jie Wee, Sazatul Nadhilah Zakaria, Nur Azwin Ismail, Carlton M. Baugh, Giorgio Manzoni, Enrique Gaztanaga, Francisco J. Castander, Martin Eriksen, Jorge Carretero, Enrique Fernandez, Juan Garcia-Bellido, Ramon Miquel, Cristobal Padilla, Pablo Renard, Eusebio Sanchez, Ignacio Sevilla-Noarbe and Pau Tallada-Crespí

{"title":"ANNZ+: an enhanced photometric redshift estimation algorithm with applications on the PAU survey","authors":"Imdad Mahmud Pathi, John Y.H. Soo, Mao Jie Wee, Sazatul Nadhilah Zakaria, Nur Azwin Ismail, Carlton M. Baugh, Giorgio Manzoni, Enrique Gaztanaga, Francisco J. Castander, Martin Eriksen, Jorge Carretero, Enrique Fernandez, Juan Garcia-Bellido, Ramon Miquel, Cristobal Padilla, Pablo Renard, Eusebio Sanchez, Ignacio Sevilla-Noarbe and Pau Tallada-Crespí","doi":"10.1088/1475-7516/2025/01/097","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/097","url":null,"abstract":"annz is a fast and simple algorithm which utilises artificial neural networks (ANNs), it was known as one of the pioneers of machine learning approaches to photometric redshift estimation decades ago. We enhanced the algorithm by introducing new activation functions like tanh, softplus, SiLU, Mish and ReLU variants; its new performance is then vigorously tested on legacy samples like the Luminous Red Galaxy (LRG) and Stripe-82 samples from SDSS, as well as modern galaxy samples like the Physics of the Accelerating Universe Survey (PAUS). This work focuses on testing the robustness of activation functions with respect to the choice of ANN architectures, particularly on its depth and width, in the context of galaxy photometric redshift estimation. Our upgraded algorithm, which we named annz+, shows that the tanh and Leaky ReLU activation functions provide more consistent and stable results across deeper and wider architectures with > 1 per cent improvement in root-mean-square error (σRMS) and 68th percentile error (σ68) when tested on SDSS data sets. While assessing its capabilities in handling high dimensional inputs, we achieved an improvement of 11 per cent in σRMS and 6 per cent in σ68 with the tanh activation function when tested on the 40-narrowband PAUS dataset; it even outperformed annz2, its supposed successor, by 44 per cent in σRMS. This justifies the effort to upgrade the 20-year-old annz, allowing it to remain viable and competitive within the photo-z community today. The updated algorithm annz+ is publicly available at https://github.com/imdadmpt/ANNzPlus.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"74 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992265","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

Universal gravitational wave signatures of cosmological solitons 宇宙孤子的普遍引力波特征

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-21 DOI: 10.1088/1475-7516/2025/01/094

Kaloian D. Lozanov, Misao Sasaki and Volodymyr Takhistov

引用次数: 0

Field-level simulation-based inference with galaxy catalogs: the impact of systematic effects 基于星系表的场级模拟推断：系统效应的影响

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-21 DOI: 10.1088/1475-7516/2025/01/082

Natalí S.M. de Santi, Francisco Villaescusa-Navarro, L. Raul Abramo, Helen Shao, Lucia A. Perez, Tiago Castro, Yueying Ni, Christopher C. Lovell, Elena Hernández-Martínez, Federico Marinacci, David N. Spergel, Klaus Dolag, Lars Hernquist and Mark Vogelsberger

{"title":"Field-level simulation-based inference with galaxy catalogs: the impact of systematic effects","authors":"Natalí S.M. de Santi, Francisco Villaescusa-Navarro, L. Raul Abramo, Helen Shao, Lucia A. Perez, Tiago Castro, Yueying Ni, Christopher C. Lovell, Elena Hernández-Martínez, Federico Marinacci, David N. Spergel, Klaus Dolag, Lars Hernquist and Mark Vogelsberger","doi":"10.1088/1475-7516/2025/01/082","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/082","url":null,"abstract":"It has been recently shown that a powerful way to constrain cosmological parameters from galaxy redshift surveys is to train graph neural networks to perform field-level likelihood-free inference without imposing cuts on scale. In particular, de Santi et al. [58] developed models that could accurately infer the value of Ωm from catalogs that only contain the positions and radial velocities of galaxies that are robust to different astrophysics and subgrid models. However, observations are affected by many effects, including (1) masking, (2) uncertainties in peculiar velocities and radial distances, and (3) different galaxy population selections. Moreover, observations only allow us to measure redshift, which entangles the galaxy radial positions and velocities. In this paper we train and test our models on galaxy catalogs, created from thousands of state-of-the-art hydrodynamic simulations run with different codes from the CAMELS project, that incorporate these observational effects. We find that while such effects degrade the precision and accuracy of the models, the fraction of galaxy catalogs for which the models retain high performance and robustness is over 90%, demonstrating the potential for applying them to real data.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"32 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992268","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

High-redshift cosmography with a possible cosmic distance duality relation violation 可能违反宇宙距离对偶关系的高红移宇宙学

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-21 DOI: 10.1088/1475-7516/2025/01/088

José F. Jesus, Mikael J.S. Gomes, Rodrigo F.L. Holanda and Rafael C. Nunes

{"title":"High-redshift cosmography with a possible cosmic distance duality relation violation","authors":"José F. Jesus, Mikael J.S. Gomes, Rodrigo F.L. Holanda and Rafael C. Nunes","doi":"10.1088/1475-7516/2025/01/088","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/088","url":null,"abstract":"In this study, we used geometric distances at high redshifts (both luminosity and angular) to perform a cosmographic analysis with the Padé method, which stabilizes the behaviour of the cosmographic series in this redshift regime. However, in our analyses, we did not assume the validity of the Cosmic Distance Duality Relation (CDDR), but allowed for potential violations, such as dL(z) = η(z)(1+z)2dA(z), where three different functional forms of η(z) are considered. By incorporating updated data from supernovae (SN), baryon acoustic oscillations (BAO), and cosmic chronometers (CC), we obtained observational constraints on cosmographic models alongside possible CDDR violations. Interestingly, we found that potential CDDR violations introduce new statistical correlations among cosmographic parameters such as H0, q0, and j0. Nonetheless, within this framework, we did not observe significant deviations from the CDDR, and our results remain consistent with the predictions of the ΛCDM model. In the same time, this work provides a novel and straightforward method for testing the CDDR by fixing the background evolution through cosmographic techniques, paving the way for new geometric observational tests of possible deviations from standard cosmology.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"205 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992316","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

Prospects for cosmological research with the FAST array: 21-cm intensity mapping survey observation strategies FAST阵列宇宙学研究展望：21厘米强度测绘巡天观测策略

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-21 DOI: 10.1088/1475-7516/2025/01/080

Jun-Da Pan, Peng-Ju Wu, Guo-Hong Du, Yichao Li and Xin Zhang

{"title":"Prospects for cosmological research with the FAST array: 21-cm intensity mapping survey observation strategies","authors":"Jun-Da Pan, Peng-Ju Wu, Guo-Hong Du, Yichao Li and Xin Zhang","doi":"10.1088/1475-7516/2025/01/080","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/080","url":null,"abstract":"Precise cosmological measurements are essential for understanding the evolution of the universe and the nature of dark energy. The Five-hundred-meter Aperture Spherical Telescope (FAST), the most sensitive single-dish radio telescope, has the potential to provide the precise cosmological measurements through neutral hydrogen 21 cm intensity mapping sky survey. This paper primarily explores the potential of technological upgrades for FAST in cosmology. The most crucial upgrade begins with equipping FAST with a wide-band receiver (0 < z < 2.5). This upgrade can enable FAST to achieve higher precision in cosmological parameter estimation than the Square Kilometre Array Phase 1 Mid-Frequency Array. On this basis, expanding to a FAST array (FASTA) consisting of six identical FASTs would offer significant improvements in precision compared to FAST. Additionally, compared with the current results from the data combination of cosmic microwave background, baryon acoustic oscillations (optical galaxy surveys), and type Ia supernovae, FASTA can provide comparable constraints. Specifically, for the dark-energy equation-of-state parameters, FASTA can achieve σ(w0) = 0.09 and σ(wa) = 0.33.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"11 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992267","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

Hot Casimir wormholes 热卡西米尔虫洞

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-21 DOI: 10.1088/1475-7516/2025/01/081

Remo Garattini and Mir Faizal

引用次数: 0

Stellar-mass black-hole binaries in LISA: characteristics and complementarity with current-generation interferometers LISA中的恒星质量黑洞双星：特征和与当前一代干涉仪的互补

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-01-21 DOI: 10.1088/1475-7516/2025/01/084

R. Buscicchio, J. Torrado, C. Caprini, G. Nardini, N. Karnesis, M. Pieroni and A. Sesana

{"title":"Stellar-mass black-hole binaries in LISA: characteristics and complementarity with current-generation interferometers","authors":"R. Buscicchio, J. Torrado, C. Caprini, G. Nardini, N. Karnesis, M. Pieroni and A. Sesana","doi":"10.1088/1475-7516/2025/01/084","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/084","url":null,"abstract":"Stellar-mass black-hole binaries are the most numerous gravitational-wave sources observed to date. Their properties make them suitable for observation both by ground- and space-based detectors. Starting from synthetic catalogues constructed based on observational constraints from ground-based detectors, we explore the detection rates and the characteristic parameters of the stellar-mass black-hole binaries observable by LISA during their inspiral, using signal-to-noise ratio thresholds as a detection criterion. We find that only a handful of these sources will be detectable with signal-to-noise ratio larger than 8: about 5 sources on average in 4 years of mission duration, among which only one or two are multiband ones (i.e. merging in less than 15 years). We find that detectable sources have chirp mass 10 M⊙ ≲ ℳc ≲ 100 M⊙, residual time-to-coalescence 4 yr ≲ τc ≲ 100 yr, and redshift z ≲ 0.1, much closer than those observed up to now by ground-based detectors. We also explore correlations between the number of LISA detectable sources and the parameters of the population, suggesting that a joint measurement with the stochastic signal might be informative of the population characteristics. By performing parameter estimation on a subset of sources from the catalogues, we conclude that, even if LISA measurements will not be directly informative on the population due to the low number of resolvable sources, it will characterise a few, low-redshift candidates with great precision. Furthermore, we construct for the first time the LISA waterfall plot for low chirp-mass systems, as a function of their time to coalescence and inclination. We demonstrate that LISA will also be able to discriminate and characterize, through very precise parameter estimation, a population of binaries with higher masses, ℳc ∼ 𝒪(103) M⊙, at the boundary of ground-based detectors sensitivity.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"103 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992313","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