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

STAR NRE: solving supernova selection effects with set-based truncated auto-regressive neural ratio estimation STAR NRE：用基于集合的截断自回归神经比率估计求解超新星选择效应

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-09 DOI: 10.1088/1475-7516/2025/07/031

Konstantin Karchev and Roberto Trotta

{"title":"STAR NRE: solving supernova selection effects with set-based truncated auto-regressive neural ratio estimation","authors":"Konstantin Karchev and Roberto Trotta","doi":"10.1088/1475-7516/2025/07/031","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/031","url":null,"abstract":"Accounting for selection effects in supernova type Ia (SN Ia) cosmology is crucial for unbiased cosmological parameter inference — even more so for the next generation of large, mostly photometric-only surveys. The conventional “bias correction” procedure has a built-in systematic bias towards the fiducial model used to derive it and fails to account for the additional Eddington bias that arises in the presence of significant redshift uncertainty. On the other hand, likelihood-based analyses within a Bayesian hierarchical model, e.g. using MCMC, scale poorly with the data set size and require explicit assumptions for the selection function that may be inaccurate or contrived. To address these limitations, we introduce STAR NRE, a simulation-based approach that makes use of a conditioned deep set neural network and combines efficient high-dimensional global inference with subsampling-based truncation in order to scale to very large survey sizes while training on sets with varying cardinality. Applying it to a simplified SN Ia model consisting of standardised brightnesses and redshifts with Gaussian uncertainties and a selection procedure based on the expected LSST sensitivity, we demonstrate precise and unbiased inference of cosmological parameters and the redshift evolution of the volumetric SN Ia rate from ≈ 100 000 mock SNæ Ia. Our inference procedure can incorporate arbitrarily complex selection criteria, including transient classification, in the forward simulator and be applied to complex data like light curves. We outline these and other steps aimed at integrating STAR NRE into an end-to-end simulation-based pipeline for the analysis of future photometric-only SN Ia data.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"697 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144603045","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

Power spectra in double-field inflation using renormalization-group techniques 利用重整化群技术研究双场膨胀中的功率谱

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-09 DOI: 10.1088/1475-7516/2025/07/030

Bohdan Grzadkowski and Marco Piva

{"title":"Power spectra in double-field inflation using renormalization-group techniques","authors":"Bohdan Grzadkowski and Marco Piva","doi":"10.1088/1475-7516/2025/07/030","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/030","url":null,"abstract":"A perturbative strategy for inflation described by two-inflaton fields is developed using a mathematical analogy with the renormalization-group. Two small quantities, α and λ, corresponding to standard slow-roll parameters are defined and systematic expansions of all inflationary quantities in terms of powers of α and λ are found. No other slow-roll parameters are needed. To illustrate this perturbative method in the multi-field context, we adopt a simple two-inflaton model with quadratic potentials in the parameter range where both fields contribute similarly to the dynamics of inflation. The model, even though it is not a viable alternative for phenomenological description of the inflationary period, nicely illustrates subtleties of the perturbative approach. In particular, this method allows us to derive two independent gauge-invariant scalar perturbations that are conserved in the superhorizon limit, overcoming typical problems that emerge in multi-field inflation. Furthermore, it is possible to perform nonperturbative resummations that allow to study the model in a true multi-field regime. We derive tensor and scalar power spectra to the next-to-next-to-leading and next-to-leading orders, respectively, as well as their spectral indices. The hierarchy between the two scalar perturbations allows us to single out the dominant entry of the scalar power-spectrum matrix. Modifications due to the second inflaton occur already at the leading order. Finally, we explain why the quadratic two-inflaton model is not compatible with the present experimental constraints even though non-trivial corrections to scalar perturbations do emerge.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"81 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144603407","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

A semi-cosmographic approach to study cosmological evolution in phase space 在相空间中研究宇宙演化的半宇宙学方法

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-09 DOI: 10.1088/1475-7516/2025/07/029

Pankaj Chavan, Tapomoy Guha Sarkar, Chandrachud B.V. Dash and Anjan A. Sen

{"title":"A semi-cosmographic approach to study cosmological evolution in phase space","authors":"Pankaj Chavan, Tapomoy Guha Sarkar, Chandrachud B.V. Dash and Anjan A. Sen","doi":"10.1088/1475-7516/2025/07/029","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/029","url":null,"abstract":"The signature of Baryon Acoustic Oscillation in the clustering of dark-matter tracers allows us to measure (DA(z), H(z)) independently. Treating these as conjugate variables, we are motivated to study cosmological evolution in the phase space of dimensionless variables x = H0DA/c and p = dx/dz. The dynamical variables (x(z),p(z)) can be integrated for a known set of equation of state parameters for different matter/energy components. However, to avoid any preference for specific dark energy models, we adopt a cosmographic approach. We consider two scenarios where the Luminosity distance is expanded as Padé rational approximants using expansion in terms of z and (1 + z)1/2 respectively. However, instead of directly using the Padé ratios to fit kinematic quantities with data, we adopt an alternative approach where the evolution of the cold dark matter sector is incorporated in our analysis through a semi-cosmographic equation of state, which is then, used to solve the dynamical problem in the phase space. The semi-cosmographic (DA(z), H(z)), thus obtained, is fitted with BAO data from DESI DR1, cosmic chronometer (CC) data and SNIa data from Pantheon+ respectively. We also consider a futuristic 21-cm intensity mapping experiment for error projections. We further use the semi-cosmographic fitting to reconstruct some diagnostics of background cosmology and compare our results for the two scenarios of Padé expansions.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"35 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144603043","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

On the dark matter origin of an LDMX signal 关于LDMX信号的暗物质起源

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-08 DOI: 10.1088/1475-7516/2025/07/020

Riccardo Catena, Taylor R. Gray and Andreas Lund

{"title":"On the dark matter origin of an LDMX signal","authors":"Riccardo Catena, Taylor R. Gray and Andreas Lund","doi":"10.1088/1475-7516/2025/07/020","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/020","url":null,"abstract":"Fixed target experiments where beam electrons are focused upon a thin target have shown great potential for probing new physics, including the sub-GeV dark matter (DM) paradigm. However, a signal in future experiments such as the light dark matter experiment (LDMX) would require an independent validation to assert its DM origin. To this end, we propose to combine LDMX and next generation DM direct detection (DD) data in a four-step analysis strategy, which we here illustrate with Monte Carlo simulations. In the first step, the hypothetical LDMX signal (i.e. an excess in the final state electron energy and transverse momentum distributions) is recorded. In the second step, a DM DD experiment operates with increasing exposure to test the DM origin of the LDMX signal. Here, LDMX and DD data are simulated. In the third step, a posterior probability density function (pdf) for the DM model parameters is extracted from the DD data, and used to predict the electron recoil energy and transverse momentum distributions at LDMX. In the last step, predicted and recorded electron recoil energy and transverse momentum distributions are compared in a chi-square test. We present the results of this comparison in terms of a threshold exposure that a DD experiment has to operate with to assert whether predicted and recorded distributions can be statistically dependent. We find that this threshold exposure grows with the DM particle mass, mχ. It varies from 0.0013 kg-year for a DM mass of mχ = 4 MeV to 1.9 kg-year for mχ = 25 MeV, which is or will soon be within reach.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"10 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144593929","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

Equatorial periodic orbits and gravitational waveforms in a black hole free of Cauchy horizon 无柯西视界黑洞的赤道周期轨道和引力波形

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-08 DOI: 10.1088/1475-7516/2025/07/021

Chao-Hui Wang, Xiang-Cheng Meng, Yu-Peng Zhang, Tao Zhu and Shao-Wen Wei

{"title":"Equatorial periodic orbits and gravitational waveforms in a black hole free of Cauchy horizon","authors":"Chao-Hui Wang, Xiang-Cheng Meng, Yu-Peng Zhang, Tao Zhu and Shao-Wen Wei","doi":"10.1088/1475-7516/2025/07/021","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/021","url":null,"abstract":"In this paper, we study the periodic orbits and gravitational wave radiation in an extreme mass ratio inspiral system, where a stellar-mass object orbits a supermassive black hole without Cauchy horizons. Firstly, by using the effective potential, the marginally bound orbits and the innermost stable circular orbits are investigated. It is found that the radius, orbital angular momentum, and energy increase with the hair parameter for both orbits. Based on these results, we examine one special type of orbit, the periodic orbit, around the black hole without the Cauchy horizon. The results show that, for a fixed rational number, the energy and angular momentum of the periodic orbit increase with the hair parameter. In particular, we observe a significant deviation from the Schwarzschild case for small hair parameter with a large amount of external mass outside the black hole horizon. Moreover, we examine the waveforms in the extreme mass ratio inspiral system to explore the orbital information of the periodic orbits and the constraints on the parameters of the black holes. The results reveal that the gravitational waveforms can fully capture the zoom-whirl behavior of periodic orbits. Moreover, the phase of the gravitational waves imposes constraints on the parameters of the black hole solutions. As the system evolves, the phase shift of the waveforms becomes increasingly significant, with cumulative deviations becoming more pronounced over time. Compared to the Schwarzschild black hole background, the waveform phase will advance for the central supermassive black hole without a Cauchy horizon.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"13 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144593930","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

Scalar-induced gravitational waves in modified gravity 修正重力中的标量诱导引力波

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-08 DOI: 10.1088/1475-7516/2025/07/022

Anjali Abirami Kugarajh, Marisol Traforetti, Andrea Maselli, Sabino Matarrese and Angelo Ricciardone

引用次数: 0

Investigating primordial black hole accretion through cosmic optical depth 通过宇宙光学深度研究原始黑洞吸积

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-08 DOI: 10.1088/1475-7516/2025/07/027

Zi-Xuan Zhang, Junsong Cang, Yu Gao and Hong Li

{"title":"Investigating primordial black hole accretion through cosmic optical depth","authors":"Zi-Xuan Zhang, Junsong Cang, Yu Gao and Hong Li","doi":"10.1088/1475-7516/2025/07/027","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/027","url":null,"abstract":"Primordial black holes (PBH) accretion in the late Universe can lead to significant mass growth. A larger mass further accelerates the accretion radiation output for PBHs with initial masses greater than one solar mass, potentially leading to a stringent energy-dumping constraint derived from observations of the cosmic microwave background. The energy injected via PBH accretion is capable of ionizing and heating the intergalactic medium (IGM), ultimately affecting the optical depth of cosmic reionization and the 21-cm signal. This work investigates primordial black hole mass growth using the Bondi-Hoyle accretion model and accounts for additional ionization and heating induced by PBHs. We derive stringent PBH abundance limits using an upper limit on optical depth set by Planck 2018 CMB measurements. We find that accretion growth significantly strengthens late-time observational constraints for primordial black holes with initial masses ranging from several solar masses up to 104 solar masses. The PBH fraction of the Universe's unobserved mass content can be constrained to fPBH, ini ∼ 10-2 to 10-7 in this mass range, and when accounting for mass evolution our constraints can be strengthened by up to one order of magnitude. In addition, we show that PBH mass growth will lead to an observable impact on the predicted hydrogen 21-cm brightness temperature.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"31 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144593936","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

A minimal axio-dilaton dark sector 最小轴膨胀暗扇区

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-08 DOI: 10.1088/1475-7516/2025/07/023

Adam Smith, Maria Mylova, Philippe Brax, Carsten van de Bruck, C.P. Burgess and Anne-Christine Davis

{"title":"A minimal axio-dilaton dark sector","authors":"Adam Smith, Maria Mylova, Philippe Brax, Carsten van de Bruck, C.P. Burgess and Anne-Christine Davis","doi":"10.1088/1475-7516/2025/07/023","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/023","url":null,"abstract":"In scalar-tensor theories it is the two-derivative sigma-model interactions that like to compete at low energies with the two-derivative interactions of General Relativity (GR) — at least once the dangerous zero-derivative terms of the scalar potential are suppressed (such as by a shift symmetry). But nontrivial two-derivative interactions require at least two scalars to exist and so never arise in the single-scalar models most commonly explored. Axio-dilaton models provide a well-motivated minimal class of models for which these self-interactions can be explored. We review this class of models and investigate whether these minimal two fields can suffice to describe both Dark Matter and Dark Energy. We find that they can — the axion is the Dark Matter and the dilaton is the Dark Energy — and that they robustly predict several new phenomena for the CMB and structure formation that can be sought in observations. These include specific types of Dark Energy evolution and small space- and time-dependent changes to particle masses post-recombination that alter the Integrated Sachs-Wolfe effect, cause small changes to structure growth and more.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"8 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144593932","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

Addendum: Fitting the DESI BAO data with dark energy driven by the Cohen-Kaplan-Nelson bound 附录：用Cohen-Kaplan-Nelson界驱动的暗能量拟合DESI BAO数据

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-08 DOI: 10.1088/1475-7516/2025/07/a01

Patrick Adolf, Martin Hirsch, Sara Krieg, Heinrich Päs and Mustafa Tabet

引用次数: 0

Calibration requirements for epoch of reionization 21-cm signal observations. Part IV. Bias and variance with time and frequency correlated residual gains 再电离21厘米信号观测历元的校准要求。第四部分：偏差和方差与时间和频率相关的剩余增益

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-07-08 DOI: 10.1088/1475-7516/2025/07/024

Saikat Gayen, Jais Kumar, Prasun Dutta, Khandakar Md Asif Elahi, Samir Choudhuri and Nirupam Roy

{"title":"Calibration requirements for epoch of reionization 21-cm signal observations. Part IV. Bias and variance with time and frequency correlated residual gains","authors":"Saikat Gayen, Jais Kumar, Prasun Dutta, Khandakar Md Asif Elahi, Samir Choudhuri and Nirupam Roy","doi":"10.1088/1475-7516/2025/07/024","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/07/024","url":null,"abstract":"Observation of multifrequency angular power spectrum of the redshifted 21-cm brightness temperature fluctuation from the neutral hydrogen holds the key to understand the structure formation and its evolution during the reionization and post-reionization era. A major challenge in observing the neutral hydrogen arises from presence of strong foreground signals in the frequency range of interest. Mitigating the direct effect of foregrounds are being addressed through various techniques in literature. An additional second order effect arises, in presence of foreground, with limited accuracy in time and frequency dependent gain calibrations. This manifests as the residual gain and bandpass error in the observed data, introduces bias and increases uncertainty in the estimates of multifrequency angular power spectrum. In this work, we present an analytic method to estimate the bias and excess uncertainty in the estimates of multifrequency angular power spectrum in presence of residual gain and bandpass errors. We use this framework to estimate the effect of these errors for detection of redshifted 21-cm emission from a redshift of ∼ 8 with the upcoming SKA1-Low. Due to the high baseline density at the required range of angular multipoles, the SKA1-Low is found to be a tuned instrument for the redshifted 21-cm signal detection. We find that, there are scenario with residual gain and bandpass errors where there can be significant bias in these estimates. Certain foreground mitigation strategies, is expected to reduce a part of the bias. The detailed study of different aspects of gain and bandpass errors and their relative effects are discussed. We find, with assumed models of gain and bandpass errors, signal detection is possible at this redshift with 128 hours of observations. However, to achieve this one needs to have better calibration accuracy than present day interferometers.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144593933","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