Journal of Cosmology and Astroparticle Physics最新文献

Assisted Fibre Inflation in perturbative LVS 微扰LVS中的辅助纤维膨胀

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-16 DOI: 10.1088/1475-7516/2025/10/070

George K. Leontaris and Pramod Shukla

引用次数: 0

Aspects of the WIMP quality problem and R-parity violation in natural supersymmetry with all axion dark matter WIMP质量问题的各个方面和自然超对称中所有轴子暗物质的r宇称破坏

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-16 DOI: 10.1088/1475-7516/2025/10/072

Howard Baer, Vernon Barger, Jessica Bolich, Dibyashree Sengupta and Kairui Zhang

{"title":"Aspects of the WIMP quality problem and R-parity violation in natural supersymmetry with all axion dark matter","authors":"Howard Baer, Vernon Barger, Jessica Bolich, Dibyashree Sengupta and Kairui Zhang","doi":"10.1088/1475-7516/2025/10/072","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/072","url":null,"abstract":"In supersymmetric models where the μ problem is solved via discrete R-symmetries, then both the global U(1)PQ (Peccei-Quinn, needed to solve the strong CP problem) and R-parity conservation (RPC, needed for proton stability) are expected to arise as accidental, approximate symmetries. Then, in some cases, SUSY dark matter is expected to be all axions since the relic lightest SUSY particles (LSPs) can decay away via small R-parity violating (RPV) couplings. We examine several aspects of this all axion SUSY dark matter scenario. 1. We catalogue the operator suppression which is gained from discrete R-symmetry breaking via four two-extra-field base models. 2. We present exact tree-level LSP decay rates including mixing and phase space effects and compare to results from simple, approximate formulae. 3. Natural SUSY models are characterized by light higgsinos with mass m ∼ 100-350 GeV so that the dominant sparticle production cross sections at LHC14 are expected to be higgsino pair production which occurs at the 102-104 fb level. Assuming nature is natural, the lack of an RPV signal from higgsino pair production in LHC data translates into rather strong upper bounds on nearly all trilinear RPV couplings in order to render the SUSY signal (nearly) invisible. Thus, in natural SUSY models with light higgsinos, the RPV-couplings must be small enough that the LSP has a rather high quality of RPC.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"131 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311123","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

Can a multi-tracer approach improve the constraints on the turnover scale at low redshift? 多示踪剂方法能否改善低红移时对周转率的限制？

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-16 DOI: 10.1088/1475-7516/2025/10/071

Y. Lai, C. Howlett and T.M. Davis

{"title":"Can a multi-tracer approach improve the constraints on the turnover scale at low redshift?","authors":"Y. Lai, C. Howlett and T.M. Davis","doi":"10.1088/1475-7516/2025/10/071","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/071","url":null,"abstract":"The turnover scale of the power spectrum is related to the size of the particle horizon at the matter-radiation equality, which can be used as a standard ruler to constrain cosmological parameters. In this work, we apply a model-independent method to mock datasets to forecast constraints on the turnover scale below a redshift of 0.5, investigating for the first time with a multi-tracer approach. We find that combining the galaxy density with peculiar velocity does not improve the turnover scale constraints for current or currently planned surveys because either the cosmological volume or the effective number density of peculiar velocities is too low. However, we demonstrate that when combining the galaxy power spectrum from 4HS with the HI power spectrum from SKA1-B2, the constraints on the turnover scale improve by ∼ 30% compared to using only a single tracer. We demonstrate for the first time that combining DESI, 4HS, and an SKA Phase 1 Band 2 survey could achieve a ∼ 5% level constraint on the turnover scale and a ∼ 90% probability of detecting the turnover below a redshift of 0.5. Lastly, we also demonstrate that combining the DESI BGS redshift sample with the LRG, ELG, and QSO samples could break the degeneracy between rH and Ωm and improve their constraints by ∼ 25% and ∼ 45%, respectively, compared to only using the high redshift samples. The constraints on the particle horizon at the matter-radiation equality rH and the matter density Ωm could then further improve by ∼ 20% and ∼ 30%, respectively, when combining the full set of DESI redshift tracers with 4HS and SKA1-B2.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311121","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

Towards a precision calculation of N eff in the Standard Model IV: Estimating the impact of positronium formation 标准模型IV中N - eff的精确计算：正电子离子形成影响的估计

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-15 DOI: 10.1088/1475-7516/2025/10/069

Tobias Binder, Marco Drewes, Yannis Georis, Michael Klasen, Giovanni Pierobon and Yvonne Y.Y. Wong

{"title":"Towards a precision calculation of N eff in the Standard Model IV: Estimating the impact of positronium formation","authors":"Tobias Binder, Marco Drewes, Yannis Georis, Michael Klasen, Giovanni Pierobon and Yvonne Y.Y. Wong","doi":"10.1088/1475-7516/2025/10/069","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/069","url":null,"abstract":"We present a first assessment of how the previously unexplored effect of positronium formation can impact on the value of the effective number of neutrino species in the Standard Model, NeffSM. Adopting a Yukawa form for the electrostatic potential, we discuss two possible scenarios that differ primarily in their assumptions about entropy evolution. The first, out-of-equilibrium scenario assumes that thermal corrections to the potential such as Debye screening prevent positronium from appearing until the temperature drops below a threshold. Once the threshold is reached, entropy generated in the QED sector from the equilibration process, if instantaneous, leads to a variation in NeffSM of at most |ΔNeff| ∼ 10-4, comparable to other uncertainties in the current benchmark value for NeffSM. A more gradual formation could however yield a larger change. The second, equilibrium scenario assumes the QED sector to stay in equilibrium at all times. In this case, we show that cancellations between the first, s-wave bound- and scattering-states contributions ensure that it is possible to evolve the system across the bound-state formation threshold without generating entropy in the QED sector. The corresponding change in NeffSM then closely matches the 𝒪(e2) perturbative result derived in previous works and the 𝒪(e2) contribution is capped at |ΔNeff| ≲ 10-6. We also comment on the impact of deviations from a pure Yukawa potential due to the presence of a thermal width.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"6 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145310751","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

Distinguishing scale-dependent Planck stars from renormalization group improved Schwarzschild black holes by gravitational waves 通过引力波区分尺度相关的普朗克恒星和重整化群改进了史瓦西黑洞

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-15 DOI: 10.1088/1475-7516/2025/10/067

Li Huang

{"title":"Distinguishing scale-dependent Planck stars from renormalization group improved Schwarzschild black holes by gravitational waves","authors":"Li Huang","doi":"10.1088/1475-7516/2025/10/067","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/067","url":null,"abstract":"Extreme mass-ratio inspirals (EMRIs), consisting of a stellar-mass black hole orbiting a supermassive black hole, are among the primary targets for future space-based gravitational wave detectors. By analyzing the emitted gravitational wave signals, we can probe the nature of compact objects in the strong-field region. To achieve this, we examine the effects of gravitational radiation. In this work, we base our calculations on the general relativistic Schwarzschild background and calculate the energy and angular momentum fluxes of gravitational waves. We perform a theoretical analysis of the equations of motion and the orbital evolution equations for EMRIs. The gravitational waveforms generated by the different periodic orbits of timelike test particles around scale-dependent Planck stars or renormalization group improved Schwarzschild black holes are investigated using both time-domain and frequency-domain methods. The time-domain method employs the “analytic kludge” (AK) approach, while the frequency-domain method utilizes the discrete Fourier transform. We calculate the characteristic strain of the corresponding gravitational waves and compare them with the sensitivity curves of both ground-based and space-based detectors. These gravitational wave sensitivity curves can be experimentally tested for both spacetimes considered. Additionally, we use two approximate methods — the large eccentricity (EL) method and the small eccentricity (ES) method — to study the orbital evolution of EMRIs and compare the results with equatorial orbits derived from geodesic equations. Our findings will contribute to a deeper understanding of the nature of spacetime.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"289 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145310700","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 quantum-corrected black holes with QPOs observations: a study of particle dynamics and accretion flow 用QPOs观测测试量子修正黑洞：粒子动力学和吸积流的研究

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-15 DOI: 10.1088/1475-7516/2025/10/068

G. Mustafa, Sushant G. Ghosh, Orhan Donmez, S.K. Maurya, Shakhzod Orzuev and Farruh Atamurotov

{"title":"Testing quantum-corrected black holes with QPOs observations: a study of particle dynamics and accretion flow","authors":"G. Mustafa, Sushant G. Ghosh, Orhan Donmez, S.K. Maurya, Shakhzod Orzuev and Farruh Atamurotov","doi":"10.1088/1475-7516/2025/10/068","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/068","url":null,"abstract":"We study the epicyclic oscillations of test particles around rotating quantum-corrected black holes (QCBHs), characterized by mass M, spin a, and the quantum deformation parameter b. By deriving the radial (Ωr) and vertical (Ωθ) oscillation frequencies, we explore their dependence on spacetime parameters and show that quantum corrections (b ≠ 0) significantly modify the dynamics compared to the classical Kerr case. Through numerical modeling of accretion around QCBHs, we further examine how b influences strong-field phenomena, comparing the results with test-particle dynamics and observational data. Our analysis reveals: (1) Quantum corrections shift the ISCOs outward, with b altering the effective potential and conditions for stable circular motion. (2) The curvature of the potential and thus the epicyclic frequencies change Ωr shows up to 25% deviation for typical b values, underscoring sensitivity to quantum effects. (3) Precession behavior is modified: while Lense-Thirring precession (ΩLT) remains primarily governed by a, periastron precession (ΩP) is notably affected by b, especially near the black hole. (4) Accretion disk simulations confirm the physical effects of b, which is aligned well with the test particle analysis. In addition, the quasiperiodic oscillation (QPO) frequencies obtained via both approaches agree with the observed low-frequency QPOs from sources like GRS 1915+105, GRO J1655-40, XTE J1550-564, and H1743-322. The distinct frequency profiles and altered ratios offer observational signatures that may distinguish QCBHs from classical black holes. Our findings present testable predictions for X-ray timing and a new avenue to constrain quantum gravity parameters.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"48 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145310701","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 classification matters: searching for primordial black holes with LSST 黑暗分类很重要：用LSST寻找原始黑洞

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-14 DOI: 10.1088/1475-7516/2025/10/066

Miguel Crispim Romao, Djuna Croon, Benedict Crossey and Daniel Godines

引用次数: 0

Using neutron stars to probe dark matter charged under a Lμ-Lτ symmetry 利用中子星探测在Lμ-Lτ对称下带电的暗物质

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-14 DOI: 10.1088/1475-7516/2025/10/060

Nicole F. Bell, Giorgio Busoni and Avirup Ghosh

引用次数: 0

Shadows and observational images of a Schwarzschild-like black hole surrounded by a Dehnen-type dark matter halo 被dehnen型暗物质晕包围的类史瓦西黑洞的阴影和观测图像

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-14 DOI: 10.1088/1475-7516/2025/10/065

Zuting Luo, Meirong Tang and Zhaoyi Xu

{"title":"Shadows and observational images of a Schwarzschild-like black hole surrounded by a Dehnen-type dark matter halo","authors":"Zuting Luo, Meirong Tang and Zhaoyi Xu","doi":"10.1088/1475-7516/2025/10/065","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/065","url":null,"abstract":"This paper investigates the optical appearance of a Schwarzschild-like black hole (BH) surrounded by a Dehnen-(1, 4, 5/2) type dark matter (DM) halo, with a focus on how the DM halo's density ρs and radius rs influence the BH's shadow and photon ring. First, the radius rh of the BH's event horizon and the equation of motion for photons were derived, and observational data from the Event Horizon Telescope (EHT) for M87* were used to constrain the parameters ρs and rs of the DM halo. Afterward, by varying the values of ρs and rs, key parameters such as the effective potential Veff of photons, the critical impact parameter bph, the radius risco of the innermost stable circular orbit, and the radius rph of the photon sphere were calculated for each case. It was found that as ρs and rs increase, the above mentioned parameters all show an increasing trend. Subsequently, we investigated the optical appearance of the BH illuminated by two types of accretion models: optically and geometrically thin disk models and spherical accretion models. The findings indicate that as ρs and rs increase, the peak of the received intensity shifts toward a higher impact parameter b, resulting in a distinct optical appearance.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"29 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145289464","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

Recovering CMB polarization maps with neural networks: performance in realistic simulations 用神经网络恢复CMB极化图：在现实模拟中的表现

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-10-14 DOI: 10.1088/1475-7516/2025/10/063

J.M. Casas, L. Bonavera, J. González-Nuevo, G. Puglisi, C. Baccigalupi, S.R. Cabo, M.M. Cueli, D. Crespo, C. González-Gutiérrez and F.J. de Cos

{"title":"Recovering CMB polarization maps with neural networks: performance in realistic simulations","authors":"J.M. Casas, L. Bonavera, J. González-Nuevo, G. Puglisi, C. Baccigalupi, S.R. Cabo, M.M. Cueli, D. Crespo, C. González-Gutiérrez and F.J. de Cos","doi":"10.1088/1475-7516/2025/10/063","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/10/063","url":null,"abstract":"Recovering the polarized cosmic microwave background (CMB) is essential for shedding light on the exponential expansion of the very early Universe, known as cosmic inflation. Achieving this goal requires not only improved instrumental sensitivity but also the development of robust and diverse data analysis techniques. In this work, we explore a novel component separation approach based on neural networks, previously validated using realistic Planck temperature simulations, to reconstruct the Stokes Q and U polarization maps. To validate the method, we first test the network on realistic Planck sky simulations of regions deliberately excluded from the training set. We compare the input and output EE and BB power spectra, finding a mean absolute error of 0.1 ± 0.3 μK2 for the E-mode and -0.1 ± 0.3 μK2 for the B-mode. These results demonstrate a partial recovery of the E-mode and a limited recovery of the B-mode, the latter remaining dominated by residual Planck noise. We then apply the trained network to public Planck observations, recovering CMB polarization maps broadly consistent with those obtained using the Commander method. The recovered EE spectra differ by less than 5% from the reference at intermediate and small angular scales, although significant discrepancies remain at large scales, which may impact cosmological interpretations. These results, while encouraging, clearly reflect the limitations of the current setup and motivate further improvements in training data and methodology. Based on these findings, we conclude that neural network-based methods show potential as component separation techniques in polarization CMB experiments. However, substantial improvements and more comprehensive analyses are necessary before these methods can provide reliable high-precision cosmological estimates.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"2 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145289258","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