{"title":"Robust evidence for dynamical dark energy from DESI galaxy-CMB lensing cross-correlation and geometric probes","authors":"Miguel A. Sabogal and Rafael C. Nunes","doi":"10.1088/1475-7516/2025/09/084","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/084","url":null,"abstract":"Recent analyses joining data from the Cosmic Microwave Background (CMB), Baryon Acoustic Oscillations (BAO), and Type Ia Supernovae (SNIa) have provided strong evidence in favor of dynamical dark energy (DDE) over a simple cosmological constant. Motivated by these findings, we present new observational constraints on DDE based on the cross-correlation between DESI Luminous Red Galaxies (LRG) samples and CMB lensing (CMBκ × LRG), which effectively probes the impact of cosmological parameters on the growth of structure at the perturbative level. We demonstrate that, when combined with geometric measurements such as BAO and SNIa, this cross-correlation yields compelling statistical evidence for DDE exceeding 4σ, including within simpler parametrizations such as the wCDM model. Remarkably, this evidence is independent of constraints from primary Planck CMB anisotropies data. These results highlight the robustness and potential of Galaxy-CMB lensing cross-correlation as a powerful observational probe of the dark sector, particularly when used in conjunction with geometric observables.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"114 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188676","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}
Ricardo Waibel, Sara Konrad and Matthias Bartelmann
{"title":"Free cosmic density bispectrum on small scales","authors":"Ricardo Waibel, Sara Konrad and Matthias Bartelmann","doi":"10.1088/1475-7516/2025/09/083","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/083","url":null,"abstract":"We study the asymptotic behaviour of the free, cold-dark matter density fluctuation bispectrum in the limit of small scales. From an initially Gaussian random field, we draw phase-space positions of test particles which then propagate along Zel'dovich trajectories. Only initial momentum-momentum correlation are considered, making the formulas identical to the typical Zel'dovich approximation. A suitable expansion of the initial momentum auto-correlations of these particles leads to an asymptotic series whose lower-order power-law exponents we calculate. The dominant contribution has an exponent of -11/2. For triangle configurations with zero surface area, this exponent is even enhanced to -9/2. These power laws can only be revealed by a non-perturbative calculation with respect to the initial power spectrum. They are valid for a general class of initial power spectra with a cut-off function, required to enforce convergence of its moments. We then confirm our analytic results numerically. Finally, we use this asymptotic behaviour to investigate the shape dependence of the bispectrum in the small-scale limit, and to show how different shapes grow over cosmic time. These confirm the usual model of gravitational collapse within the Zel'dovich picture.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"327 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188681","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}
{"title":"Testing the consistency of new Amati-correlated gamma-ray burst dataset cosmological constraints with those from better-established cosmological data","authors":"Shulei Cao and Bharat Ratra","doi":"10.1088/1475-7516/2025/09/081","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/081","url":null,"abstract":"Gamma-ray bursts (GRBs) are promising cosmological probes for exploring the Universe at intermediate redshifts (z). We analyze 151 Fermi-observed long GRBs (datasets A123 and A28) to simultaneously constrain the Amati correlation and cosmological parameters within six spatially flat and nonflat dark energy models. We find that these datasets are standardizable via a single Amati correlation, suggesting their potential for cosmological analyses. However, constraints on the current value of the nonrelativistic matter density parameter from A123 and the combined A123 + A28 data exhibit > 2σ tension with those derived from a joint analysis of better-established Hubble parameter [H(z)] and baryon acoustic oscillation (BAO) data for most considered cosmological models. This tension indicates that these GRB data are unsuitable for jointly constraining cosmological parameters with better-established H(z) + BAO and similar data. Although the A28 data constraints are consistent with the H(z) + BAO data constraints, its limited sample size (28 GRBs) and high intrinsic scatter (∼0.7) diminishes its statistical power compared to existing datasets.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"92 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188678","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}
{"title":"Increase of ns in regularized pole inflation & Einstein-Cartan gravity","authors":"Minxi He, Muzi Hong and Kyohei Mukaida","doi":"10.1088/1475-7516/2025/09/080","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/080","url":null,"abstract":"We show that the regularization of the second order pole in the pole inflation can induce the increase of ns, which may be important after the latest data release of cosmic microwave background (CMB) observation by Atacama Cosmology Telescope (ACT). Pole inflation is known to provide a unified description of attractor models that they can generate a flat plateau for inflation given a general potential. Recent ACT observation suggests that the constraint on the scalar spectral index ns at CMB scale may be shifted to a larger value than the predictions in the Starobinsky model, the Higgs inflation, and the α-attractor model, which motivates us to consider the modification of the pole inflation. We find that if we regularize the second order pole in the kinetic term such that the kinetic term becomes regular for all field range, we can generally increase n_s because the potential in the large field regime will be lifted. We have explicitly demonstrated that this type of regularized pole inflation can naturally arise from the Einstein-Cartan formalism, and the inflationary predictions are consistent with the latest ACT data without spoiling the success of the α-attractor models.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"31 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188682","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}
{"title":"PQ-ball and its real scalar analogue in an expanding universe","authors":"Kazunori Nakayama and Masaki Yamada","doi":"10.1088/1475-7516/2025/09/082","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/082","url":null,"abstract":"We demonstrate the formation of quasi-stable localized scalar configurations in spontaneously symmetry breaking U(1) model by 3+1-dimensional classical lattice simulations. Such configurations are called PQ-balls, as the primary motivation of this kind of configuration is Peccei-Quinn theory under the kinetic misalignment mechanism. Our numerical simulations demonstrate that they can form if the PQ charge is generated through the coherent rotation of a complex scalar field in the complex plane, via dynamics analogous to the Affleck-Dine mechanism. These configurations subsequently decay due to the U(1)-breaking effect induced by spontaneous symmetry breaking. We also demonstrate the formation and decay of oscillons in a similar setup in a real scalar field theory.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"28 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188679","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}
Camilla T.G. Sørensen, Steen Hannestad and Thomas Tram
{"title":"Cosmic curl — features and convergence of the vorticity power spectrum in N-body simulations","authors":"Camilla T.G. Sørensen, Steen Hannestad and Thomas Tram","doi":"10.1088/1475-7516/2025/09/079","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/079","url":null,"abstract":"Observations of the cosmic velocity field could become an important cosmological probe in the near future. To take advantage of future velocity-flow surveys we must however have the theoretical predictions under control. In many respects, the velocity field is easier to simulate than the density field because it is less severely affected by small-scale clustering. Therefore, as we also show in this paper, a particle-mesh (PM) based simulation approach is usually sufficient, yielding results within a few percent of a corresponding P3M simulation in which short-range forces are properly accounted for, but which also carry a much larger computational cost. However, in other respects the velocity field is much more challenging to deal with than the density field: interpolating the velocity field onto a grid is significantly more complicated, and the vorticity field (the curl-part of the velocity field) is severely affected by both sample variance and discretisation effects. While the former can be dealt with using fixed amplitude initial conditions, the former makes it infeasible to run fully converged simulations in a cosmological volume. However, using the N-body code we show that one can robustly extrapolate the cosmic vorticity power spectrum from just 4 simulations with different number of particles. We expect our extrapolated vorticity power spectra to be correct within 5% of the fully converged result across three orders of magnitude in k. Finally, we have also investigated the time dependence of the vorticity as well as the ratio of vorticity to divergence.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"20 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188755","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}
{"title":"Improved cosmological limits on Z' models with light right-handed neutrinos","authors":"Tim Herbermann and Manfred Lindner","doi":"10.1088/1475-7516/2025/09/078","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/078","url":null,"abstract":"We improve limits on extensions of the Standard Model (SM) with light right-handed neutrinos. The presence of shared gauge interactions between the light right-handed neutrinos and other SM fermions allows for production of νR in the early Universe and we use the excess in the effective number of neutrino species ΔNeff to place limits. Our benchmark model is a minimal gauged U(1)B-L that often arises as a building block in other models, and we discuss applicability to more general U(1) extensions. We devise an improved Monte Carlo integration scheme convenient for implementation of generic integrated Boltzmann equations with minimal simplifying assumptions. We sketch our numerical implementation in detail for future reference. Using the new ACT DR6 limit ΔNeff < 0.17, we improve constraints on the gauge coupling for 1 GeV < mZ' < 100 TeV by orders of magnitude and find the strongest limits thus far, surpassing even current and future colliders, and explore the potential of future CMB experiments to test U(1) extensions up to the GUT scale. We perform a detailed analysis of the robustness of cosmological limits within standard and non-standard thermal histories and find that a strong first order phase transition, early dark energy or early matter domination could dilute νR abundances beyond detection. We investigate the effect of reheating on νR-genesis and provide results and prescriptions to apply our bounds to non-standard thermal histories. Limits are generically weakened for reheating Treh ≪ mZ'. Our results suggest that projected limits on Z' with Dirac neutrinos can only be accommodated for in non-standard thermal histories, thus limiting the options to include dark matter candidates or Dirac leptogenesis.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"19 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188677","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}
Andrea Costantini, Laura Iacconi and David J. Mulryne
{"title":"Primordial correlators from multi-point propagators","authors":"Andrea Costantini, Laura Iacconi and David J. Mulryne","doi":"10.1088/1475-7516/2025/09/077","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/077","url":null,"abstract":"A key step in the comparison between inflationary predictions and cosmological observations is the computation of primordial correlators. Numerical methods have been developed that overcome some of the difficulties arising in analytical calculations when the models considered are complex. The PyTransport package, which implements the transport formalism, allows computation of the tree-level 2- and 3-point correlation functions for multi-field models with arbitrary potentials and a curved field space. In this work we investigate an alternative numerical implementation of the transport approach, based on the use of transfer “matrices” called multi-point propagators (MPP). We test the novel MPP method, and extensively compare it with the traditional implementation of the transport approach provided in PyTransport. We highlight advantages of the former, discussing its performance in terms of accuracy, precision and running time, as well as dependence on the number of e-folds of sub-horizon evolution and tolerance settings. For topical ultra-slow-roll models of inflation we show that MPPs (i) precisely track the decay of correlators even when PyTransport produces erroneous results, (ii) extend the computation of squeezed bispectra for squeezing values at least one decade beyond those attainable with PyTransport.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"18 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141378","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}
{"title":"A non-commutative Kalb-Ramond black hole","authors":"A.A. Araújo Filho, N. Heidari and Iarley P. Lobo","doi":"10.1088/1475-7516/2025/09/076","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/076","url":null,"abstract":"This work presents a new black hole solution within the framework of a non-commutative gauge theory applied to Kalb-Ramond gravity. Using the method recently proposed in the literature [Nucl.Phys.B 1017 (2025) 116950], we employ the Moyal twist ∂r∧∂θ to implement non-commutativity, being encoded by parameter Θ. We begin by verifying that the resulting black hole no longer possesses spherical symmetry, while the event horizon remains unaffected by non-commutative corrections. The Kretschmann scalar is computed to assess the corresponding regularity. It turns out that the solution is regular, provided that the Christoffel symbols and related quantities are not expanded to second order in Θ. We derive the thermodynamic quantities, including the Hawking temperature T(Θ,ℓ), entropy S(Θ,ℓ), and heat capacity CV(Θ,ℓ). The remnant mass Mrem is estimated by imposing T(Θ,ℓ) → 0, although the absence of a physical remnant indicates complete evaporation. Quantum radiation for bosons and fermions is analyzed via the tunneling method, where divergent integrals are treated using the residue theorem. Notably, in the low-frequency regime, the particle number density for bosons surpasses that of fermions (at least within the scope of the methods considered here). The effective potential for a massless scalar field is obtained perturbatively, enabling the computation of quasinormal modes and the time-domain profiles. Finally, further bounds on Θ and ℓ (Lorentz-violating paramter) are derived from solar system tests, including the perihelion precession of Mercury, light deflection, and the Shapiro time delay.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"57 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145133434","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}
M. Ballardini, A. Gruppuso, S. Paradiso, S.S. Sirletti and P. Natoli
{"title":"Planck constraints on the scale dependence of isotropic cosmic birefringence","authors":"M. Ballardini, A. Gruppuso, S. Paradiso, S.S. Sirletti and P. Natoli","doi":"10.1088/1475-7516/2025/09/075","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/09/075","url":null,"abstract":"The rotation of the linear polarisation plane of photons during propagation, also known as cosmic birefringence, is a powerful probe of parity-violating extensions of standard electromagnetism. Using Planck legacy data, we confirm previous estimates of the isotropic birefringence angle, finding β ≃ 0.30±0.05 [deg] at 68% CL, not including the systematic error from the instrumental polarisation angle. If this is a genuine signal, it could be explained by theories of Chern-Simons-type coupled to electromagnetism, which could lead to a harmonic scale-dependent birefringence signal, if the hypothesis of an ultra-light (pseudo) scalar field does not hold. To investigate these models, we pursue two complementary approaches: first, we fit the birefringence angle estimated at different multipoles, βℓ, with a power-law model and second, we perform a non-parametric Bayesian reconstruction of it. Both methods yield results consistent with a non-vanishing constant birefringence angle. The first method shows no significant dependence on the harmonic scale (up to 1.8σ CL), while the second method demonstrates that a constant model is favored by Bayesian evidence. This conclusion is robust across all four published Planck CMB solutions. Finally, we forecast that upcoming CMB observations by Simons Observatory, LiteBIRD and a wishful CMB-Stage 4 experiment could reduce current uncertainties by a factor of approximately 7.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"3 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145133862","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}