Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/045
Claudio Ranucci, Alessandro Carones, Léo Vacher, Nicoletta Krachmalnicoff and Carlo Baccigalupi
The detection of primordial B-mode polarisation of the Cosmic Microwave Background (CMB) is a major observational goal in modern Cosmology, offering a potential window into inflationary physics through the measurement of the tensor-to-scalar ratio r. However, the presence of Galactic foregrounds poses significant challenges, possibly biasing the r estimate. In this study we explore the viability of using Minkowski functionals (MFs) as a robustness test to validate a potential r detection by identifying non-Gaussian features associated with foregrounds contamination. To do so, we simulate sky maps as observed by a LiteBIRD-like CMB experiment, with realistic instrumental and foregrounds modelling. The CMB B-mode signal is recovered through blind component separation algorithms, and the obtained (biased) value of r is used to generate Gaussian realisation of CMB signal. Their MFs are then compared with those computed on maps contaminated by foreground residual left by component separation, looking for a detection of non-Gaussianity. Our results demonstrate that, with the experimental configuration considered here, MFs can not be reliably adopted as a robustness test of an eventual r detection, as we find that in the majority of the cases MFs are not able to raise significant warnings about the non-Gaussianity induced by the presence of foreground residuals. In the most realistic and refined scenario we adopted, the test is able to flag non-Gaussianity in ∼ 26% of the simulations, meaning that there is no warning on the biased tensor-to-scalar ratio in ∼ 74% of cases. These results suggest that more advanced statistics than MFs must be considered to look for non-Gaussian signatures of foregrounds, in order to be able to perform reliable null tests in future CMB missions.
{"title":"B-sure. Part I. Minkowski functionals as robustness test for tensor-to-scalar ratio detection from CMB observations","authors":"Claudio Ranucci, Alessandro Carones, Léo Vacher, Nicoletta Krachmalnicoff and Carlo Baccigalupi","doi":"10.1088/1475-7516/2026/01/045","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/045","url":null,"abstract":"The detection of primordial B-mode polarisation of the Cosmic Microwave Background (CMB) is a major observational goal in modern Cosmology, offering a potential window into inflationary physics through the measurement of the tensor-to-scalar ratio r. However, the presence of Galactic foregrounds poses significant challenges, possibly biasing the r estimate. In this study we explore the viability of using Minkowski functionals (MFs) as a robustness test to validate a potential r detection by identifying non-Gaussian features associated with foregrounds contamination. To do so, we simulate sky maps as observed by a LiteBIRD-like CMB experiment, with realistic instrumental and foregrounds modelling. The CMB B-mode signal is recovered through blind component separation algorithms, and the obtained (biased) value of r is used to generate Gaussian realisation of CMB signal. Their MFs are then compared with those computed on maps contaminated by foreground residual left by component separation, looking for a detection of non-Gaussianity. Our results demonstrate that, with the experimental configuration considered here, MFs can not be reliably adopted as a robustness test of an eventual r detection, as we find that in the majority of the cases MFs are not able to raise significant warnings about the non-Gaussianity induced by the presence of foreground residuals. In the most realistic and refined scenario we adopted, the test is able to flag non-Gaussianity in ∼ 26% of the simulations, meaning that there is no warning on the biased tensor-to-scalar ratio in ∼ 74% of cases. These results suggest that more advanced statistics than MFs must be considered to look for non-Gaussian signatures of foregrounds, in order to be able to perform reliable null tests in future CMB missions.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"65 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044741","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/051
Dibya S. Chattopadhyay, Basudeb Dasgupta, Amol Dighe and Mayank Narang
Coupling of axions or axion-like particles (ALPs) with photons may lead to photons escaping optically opaque regions by oscillating into ALPs. This phenomenon may be viewed as the Light Shining through Wall (LSW) scenario. While this LSW technique has been used previously in controlled laboratory settings to constrain the ALP-photon coupling (gaγ), we show that this can also be applied in astrophysical environments. We find that obscured magnetars in particular are excellent candidates for this purpose. A fraction of photons emitted by the magnetar may convert to ALPs in the magnetar neighborhood, cross the large absorption column densities, and convert back into photons due to the interstellar magnetic field. Comparing the observed flux with the estimated intrinsic flux from the magnetar, we can constrain the contribution of this process, and hence constrain gaγ. The effects of resonant conversion near the magnetar as well as ALP-photon oscillations in the interstellar medium are carefully considered. Taking a suitable magnetar candidate PSR J1622-4950, we find that the ALP-photon coupling can be constrained at gaγ ≲ (10-10 - few × 10-11) GeV-1 for low mass axions (ma ≲ 10-12 eV). Our study reveals the previously unrealized potential for employing the LSW technique for obscured magnetars for probing and constraining ALP-photon couplings.
轴子或类轴子粒子（ALPs）与光子的耦合可能导致光子通过振荡进入类轴子粒子而逃离光学不透明区域。这种现象可以看作是光穿墙（LSW）场景。虽然这种LSW技术以前曾在受控的实验室环境中用于约束alp -光子耦合（gaγ），但我们表明这也可以应用于天体物理环境。我们发现被遮蔽的磁星尤其适合这一目的。磁星发射的光子的一小部分可能会在磁星附近转换成阿尔卑斯，穿过大的吸收柱密度，并在星际磁场的作用下转换回光子。将观测到的通量与估计的磁星本质通量进行比较，我们可以约束这一过程的贡献，从而约束γ。仔细考虑了磁星附近的共振转换以及星际介质中alp -光子振荡的影响。以合适的磁星候选者PSR J1622-4950为例，我们发现对于低质量轴子（ma≤10-12 eV）， alp -光子耦合可以被限制在gaγ≤(10-10 - few × 10-11) GeV-1。我们的研究揭示了利用LSW技术探测和约束alp -光子耦合的潜在潜力。
{"title":"Light shining through wall bounds on axions from obscured magnetars","authors":"Dibya S. Chattopadhyay, Basudeb Dasgupta, Amol Dighe and Mayank Narang","doi":"10.1088/1475-7516/2026/01/051","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/051","url":null,"abstract":"Coupling of axions or axion-like particles (ALPs) with photons may lead to photons escaping optically opaque regions by oscillating into ALPs. This phenomenon may be viewed as the Light Shining through Wall (LSW) scenario. While this LSW technique has been used previously in controlled laboratory settings to constrain the ALP-photon coupling (gaγ), we show that this can also be applied in astrophysical environments. We find that obscured magnetars in particular are excellent candidates for this purpose. A fraction of photons emitted by the magnetar may convert to ALPs in the magnetar neighborhood, cross the large absorption column densities, and convert back into photons due to the interstellar magnetic field. Comparing the observed flux with the estimated intrinsic flux from the magnetar, we can constrain the contribution of this process, and hence constrain gaγ. The effects of resonant conversion near the magnetar as well as ALP-photon oscillations in the interstellar medium are carefully considered. Taking a suitable magnetar candidate PSR J1622-4950, we find that the ALP-photon coupling can be constrained at gaγ ≲ (10-10 - few × 10-11) GeV-1 for low mass axions (ma ≲ 10-12 eV). Our study reveals the previously unrealized potential for employing the LSW technique for obscured magnetars for probing and constraining ALP-photon couplings.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"58 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044919","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/047
Francesco Verdiani, Emanuele Castorina, Ennio Salvioni and Emiliano Sefusatti
We initiate a systematic study of the perturbative nonlinear dynamics of cosmological fluctuations in dark sectors comprising a fraction of non-cold dark matter, for example ultra-light axions or light thermal relics. These mixed dark matter scenarios exhibit suppressed growth of perturbations below a characteristic, cosmologically relevant, scale associated with the microscopic nature of the non-cold species. As a consequence, the scale-free nonlinear solutions developed for pure cold dark matter and for massive neutrinos do not, in general, apply. We thus extend the Effective Field Theory of Large Scale Structure to model the coupled fluctuations of the cold and non-cold dark matter components, describing the latter as a perfect fluid with finite sound speed at linear level. We provide new analytical solutions wherever possible and devise an accurate and computationally tractable prescription for the evaluation of the one-loop galaxy power spectrum, which can be applied to probe mixed dark matter scenarios with current and upcoming galaxy survey data. As a first application of this framework, we derive updated constraints on the energy density in ultra-light axions using a combination of Planck and BOSS data. Our refined theoretical modeling leads to somewhat weaker bounds compared to previous analyses.
{"title":"The Effective Field Theory of Large Scale Structure for mixed dark matter scenarios","authors":"Francesco Verdiani, Emanuele Castorina, Ennio Salvioni and Emiliano Sefusatti","doi":"10.1088/1475-7516/2026/01/047","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/047","url":null,"abstract":"We initiate a systematic study of the perturbative nonlinear dynamics of cosmological fluctuations in dark sectors comprising a fraction of non-cold dark matter, for example ultra-light axions or light thermal relics. These mixed dark matter scenarios exhibit suppressed growth of perturbations below a characteristic, cosmologically relevant, scale associated with the microscopic nature of the non-cold species. As a consequence, the scale-free nonlinear solutions developed for pure cold dark matter and for massive neutrinos do not, in general, apply. We thus extend the Effective Field Theory of Large Scale Structure to model the coupled fluctuations of the cold and non-cold dark matter components, describing the latter as a perfect fluid with finite sound speed at linear level. We provide new analytical solutions wherever possible and devise an accurate and computationally tractable prescription for the evaluation of the one-loop galaxy power spectrum, which can be applied to probe mixed dark matter scenarios with current and upcoming galaxy survey data. As a first application of this framework, we derive updated constraints on the energy density in ultra-light axions using a combination of Planck and BOSS data. Our refined theoretical modeling leads to somewhat weaker bounds compared to previous analyses.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"25 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044740","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/043
Laura Reymond, Alexander Reeves, Pierre Zhang and Alexandre Refregier
The upcoming stage IV wide-field surveys will provide high precision measurements of the large-scale structure (LSS) of the universe. Their interpretation requires fast and accurate theoretical predictions including large scales. For this purpose, we introduce SwiftCℓ, a fast, accurate and differentiable JAX-based pipeline for the computation of the angular power spectrum beyond the Limber approximation. It uses a new FFTLog-based method which can reach arbitrary precision and includes interpolation along k, allowing for k-dependent growth factor and biases. SwiftCℓ includes a wide range of probes and effects such as galaxy clustering, including magnification bias, redshift-space distortions and primordial non-Gaussianity, weak lensing, including intrinsic alignment, cosmic microwave background (CMB) lensing and CMB integrated Sachs-Wolfe effect. We compare our pipeline to the other available beyond-Limber codes within the N5K challenge from the Rubin Observatory Legacy Survey of Space and Time (LSST) Dark Energy Science Collaboration. SwiftCℓ computes the 120 different angular power spectra over 103 ℓ-multipoles in 5 ms on one GPU core while the computation of the gradient is approximately 4× slower. Using a pre-calculation, SwiftCℓ is thus about 40× faster than the winner of the N5K challenge with comparable accuracy. Furthermore, all outputs are auto-differentiable, facilitating gradient-based sampling and robust and accurate Fisher forecasts. We showcase a Markov Chain Monte Carlo, a Hamiltonian Monte Carlo and a Fisher forecast on an LSST-like survey, illustrating SwiftCℓ's differentiability, speed and reliability in measuring cosmological parameters. The code is publicly available at https://cosmo-gitlab.phys.ethz.ch/cosmo_public/swiftcl.
{"title":"SwiftC ℓ: fast differentiable angular power spectra beyond Limber","authors":"Laura Reymond, Alexander Reeves, Pierre Zhang and Alexandre Refregier","doi":"10.1088/1475-7516/2026/01/043","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/043","url":null,"abstract":"The upcoming stage IV wide-field surveys will provide high precision measurements of the large-scale structure (LSS) of the universe. Their interpretation requires fast and accurate theoretical predictions including large scales. For this purpose, we introduce SwiftCℓ, a fast, accurate and differentiable JAX-based pipeline for the computation of the angular power spectrum beyond the Limber approximation. It uses a new FFTLog-based method which can reach arbitrary precision and includes interpolation along k, allowing for k-dependent growth factor and biases. SwiftCℓ includes a wide range of probes and effects such as galaxy clustering, including magnification bias, redshift-space distortions and primordial non-Gaussianity, weak lensing, including intrinsic alignment, cosmic microwave background (CMB) lensing and CMB integrated Sachs-Wolfe effect. We compare our pipeline to the other available beyond-Limber codes within the N5K challenge from the Rubin Observatory Legacy Survey of Space and Time (LSST) Dark Energy Science Collaboration. SwiftCℓ computes the 120 different angular power spectra over 103 ℓ-multipoles in 5 ms on one GPU core while the computation of the gradient is approximately 4× slower. Using a pre-calculation, SwiftCℓ is thus about 40× faster than the winner of the N5K challenge with comparable accuracy. Furthermore, all outputs are auto-differentiable, facilitating gradient-based sampling and robust and accurate Fisher forecasts. We showcase a Markov Chain Monte Carlo, a Hamiltonian Monte Carlo and a Fisher forecast on an LSST-like survey, illustrating SwiftCℓ's differentiability, speed and reliability in measuring cosmological parameters. The code is publicly available at https://cosmo-gitlab.phys.ethz.ch/cosmo_public/swiftcl.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"288 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044917","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/050
G. Autieri, M. Berti, M. Spinelli, B.S. Haridasu and M. Viel
We explore the constraining power of future 21cm intensity mapping (IM) observations at the SKAO, focusing primarily on the sum of neutrino masses, Σmν. We forecast observations of the 21cm IM auto-power spectrum as well as the 21cm IM and galaxy surveys cross-correlation power spectrum. We construct different synthetic data sets of observations for the 21cm IM observables in the redshift range 0 < z < 3. For galaxy clustering, we consider two stage-IV surveys to mimic a DESI-like and Euclid-like cross-correlation signal. We study the impact of assuming three different fiducial values for the sum of neutrino masses, i.e. Σmν = 0.06, 0.1, 0.4 eV, in the synthetic data sets. To investigate the constraining power of the forecasted 21cm observations, we build a likelihood code that will be made publicly available upon publication. The results of the analysis, obtained through Markov Chain Monte Carlo techniques, are promising. We find that the 21cm auto-power spectrum alone could provide an upper limit on the sum of neutrino masses of Σmν < 0.287 eV, at 95% confidence level, for the case of the lowest fiducial value of Σmν. This result is comparable to the upper limits provided by cosmic microwave background (CMB) observations alone. When combining the 21cm auto-power spectrum synthetic data set with Planck 2018 CMB measurements, we find a tighter upper limit of Σmν < 0.105 eV, which improves on the constraints from Planck alone. We obtain a similar result already at the level of 21cm and galaxy clustering cross-correlation power spectrum, whose detection is more easily achieved as they are less affected by systematic effects. Combining synthetic data sets with Planck 2018 data, we find the upper limits of Σmν < 0.116 eV and Σmν < 0.117 eV for the 21cm signal in cross-correlation with the DESI-like and Euclid-like surveys, respectively. These constraints are comparable to those obtained by combining Planck data with the 21cm auto-power spectrum synthetic data sets, thus supporting the case for 21cm cross-correlation detections.
{"title":"Weighing neutrinos with 21cm intensity mapping at the SKAO","authors":"G. Autieri, M. Berti, M. Spinelli, B.S. Haridasu and M. Viel","doi":"10.1088/1475-7516/2026/01/050","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/050","url":null,"abstract":"We explore the constraining power of future 21cm intensity mapping (IM) observations at the SKAO, focusing primarily on the sum of neutrino masses, Σmν. We forecast observations of the 21cm IM auto-power spectrum as well as the 21cm IM and galaxy surveys cross-correlation power spectrum. We construct different synthetic data sets of observations for the 21cm IM observables in the redshift range 0 < z < 3. For galaxy clustering, we consider two stage-IV surveys to mimic a DESI-like and Euclid-like cross-correlation signal. We study the impact of assuming three different fiducial values for the sum of neutrino masses, i.e. Σmν = 0.06, 0.1, 0.4 eV, in the synthetic data sets. To investigate the constraining power of the forecasted 21cm observations, we build a likelihood code that will be made publicly available upon publication. The results of the analysis, obtained through Markov Chain Monte Carlo techniques, are promising. We find that the 21cm auto-power spectrum alone could provide an upper limit on the sum of neutrino masses of Σmν < 0.287 eV, at 95% confidence level, for the case of the lowest fiducial value of Σmν. This result is comparable to the upper limits provided by cosmic microwave background (CMB) observations alone. When combining the 21cm auto-power spectrum synthetic data set with Planck 2018 CMB measurements, we find a tighter upper limit of Σmν < 0.105 eV, which improves on the constraints from Planck alone. We obtain a similar result already at the level of 21cm and galaxy clustering cross-correlation power spectrum, whose detection is more easily achieved as they are less affected by systematic effects. Combining synthetic data sets with Planck 2018 data, we find the upper limits of Σmν < 0.116 eV and Σmν < 0.117 eV for the 21cm signal in cross-correlation with the DESI-like and Euclid-like surveys, respectively. These constraints are comparable to those obtained by combining Planck data with the 21cm auto-power spectrum synthetic data sets, thus supporting the case for 21cm cross-correlation detections.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"58 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044744","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/052
Shuailiang Ge, Yuxin Liu, Jing Shu and Yue Zhao
The recent detection of gravitational waves from a binary merger involving a potential low-mass gap black hole (LMBH) by LIGO-Virgo-KAGRA (LVK) Collaboration motivates investigations into mechanisms beyond conventional stellar evolution theories to account for their existence. We study a mechanism in which dark matter (DM), through its capture and accumulation inside main sequence stars, induces the formation of black holes within the mass range of [3, 5]M⊙. We examine the distribution of these LMBHs as a function of galaxy halo mass, particularly when paired with neutron stars. This gives a distinct signature that can be tested with future gravitational wave observations. We find that a viable portion of the DM parameter space predicts a merger rate of such binaries consistent with LVK observations.
{"title":"Dark matter-induced low-mass gap black hole echoing LVK observations","authors":"Shuailiang Ge, Yuxin Liu, Jing Shu and Yue Zhao","doi":"10.1088/1475-7516/2026/01/052","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/052","url":null,"abstract":"The recent detection of gravitational waves from a binary merger involving a potential low-mass gap black hole (LMBH) by LIGO-Virgo-KAGRA (LVK) Collaboration motivates investigations into mechanisms beyond conventional stellar evolution theories to account for their existence. We study a mechanism in which dark matter (DM), through its capture and accumulation inside main sequence stars, induces the formation of black holes within the mass range of [3, 5]M⊙. We examine the distribution of these LMBHs as a function of galaxy halo mass, particularly when paired with neutron stars. This gives a distinct signature that can be tested with future gravitational wave observations. We find that a viable portion of the DM parameter space predicts a merger rate of such binaries consistent with LVK observations.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044745","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/044
Tursunali Xamidov, Sanjar Shaymatov, Bobomurat Ahmedov and Tao Zhu
In this study, we explore the influence of the quantum correction parameter ξ on the motion of particles and the properties of quasiperiodic oscillations (QPOs) around a quantum-corrected black hole (QCBH). We first analyze the geodesics of a test particle and derive weak-field constraints on parameter ξ from the perihelion precession of orbits, using observations from the Solar System and the S2 star's orbit around SgrA★ supermassive black hole in the center of our galaxy. We obtain ξ ≤ 0.01869 and ξ ≤ 0.73528 using the analysis of Solar System observations and the orbit of the S2 star around SgrA★, respectively. In the strong-field regime, we examine the dynamics of epicyclic motion around astrophysical black holes and, using observational data from four QPO sources and the Markov Chain Monte Carlo (MCMC) method, we determine the upper constraint ξ ≤ 2.086. Our results provide new insights into the effects of quantum corrections on black hole spacetimes and highlight the potential of QPOs as a probe for testing quantum gravity in astrophysical environments.
{"title":"Probing quantum corrected black hole through astrophysical tests with the orbit of S2 star and quasiperiodic oscillations","authors":"Tursunali Xamidov, Sanjar Shaymatov, Bobomurat Ahmedov and Tao Zhu","doi":"10.1088/1475-7516/2026/01/044","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/044","url":null,"abstract":"In this study, we explore the influence of the quantum correction parameter ξ on the motion of particles and the properties of quasiperiodic oscillations (QPOs) around a quantum-corrected black hole (QCBH). We first analyze the geodesics of a test particle and derive weak-field constraints on parameter ξ from the perihelion precession of orbits, using observations from the Solar System and the S2 star's orbit around SgrA★ supermassive black hole in the center of our galaxy. We obtain ξ ≤ 0.01869 and ξ ≤ 0.73528 using the analysis of Solar System observations and the orbit of the S2 star around SgrA★, respectively. In the strong-field regime, we examine the dynamics of epicyclic motion around astrophysical black holes and, using observational data from four QPO sources and the Markov Chain Monte Carlo (MCMC) method, we determine the upper constraint ξ ≤ 2.086. Our results provide new insights into the effects of quantum corrections on black hole spacetimes and highlight the potential of QPOs as a probe for testing quantum gravity in astrophysical environments.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"13 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044739","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/046
Oem Trivedi
Building on initial work on the Thermodynamic Split Conjecture (TSC), which posits that black hole and cosmological horizon thermodynamics are generically inequivalent, we examine the consequences of that split for the Gibbons-Hawking temperature and its role across cosmology. We consider many key results in both early and late universe cosmology and show that many important results such as those governing eternal inflation, vacuum tunneling, quantum breaking and primordial black holes can change. The analysis further reveals that small, TSC motivated corrections to horizon thermodynamics can subtly modify Friedmann dynamics, potentially helping to address the H0 and S8 tensions. The work thus provides a unified route from quantum gravity motivated thermodynamics to observational cosmology and motivates dedicated tests of the thermal laws governing the Universe itself.
{"title":"Cosmological implications of thermodynamic split conjecture","authors":"Oem Trivedi","doi":"10.1088/1475-7516/2026/01/046","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/046","url":null,"abstract":"Building on initial work on the Thermodynamic Split Conjecture (TSC), which posits that black hole and cosmological horizon thermodynamics are generically inequivalent, we examine the consequences of that split for the Gibbons-Hawking temperature and its role across cosmology. We consider many key results in both early and late universe cosmology and show that many important results such as those governing eternal inflation, vacuum tunneling, quantum breaking and primordial black holes can change. The analysis further reveals that small, TSC motivated corrections to horizon thermodynamics can subtly modify Friedmann dynamics, potentially helping to address the H0 and S8 tensions. The work thus provides a unified route from quantum gravity motivated thermodynamics to observational cosmology and motivates dedicated tests of the thermal laws governing the Universe itself.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"21 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044742","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/049
Mattia Bruno, Niccolò Forzano, Marco Panero and Antonio Smecca
The hypothesis that dark matter could be a bound state of a strongly coupled non-Abelian gauge theory is theoretically appealing and has a variety of interesting phenomenological implications. In particular, an interpretation of dark matter as the lightest glueball state in the spectrum of a dark Yang-Mills theory, possibly coupled to the visible sector only through gravitational interactions, has been discussed quite extensively in the literature, but most of previous work has been focused on dark SU(N) gauge theories. In this article, we consider an alternative model, based on a symplectic gauge group, which has a first-order confinement/deconfinement phase transition at a finite critical temperature. We first determine the equation of state of this theory, focusing on temperatures close to the transition, and evaluating the associated latent heat. Then we discuss the evolution of this dark-matter model in the early universe, commenting on the mechanisms by which it could indirectly interact with the visible sector, on the spectrum of gravitational waves it could produce, and on the relic abundances it would lead to. Our discussion includes an extensive review of relevant literature, a number of comments on similarities and differences between our model and dark SU(N) gauge theories, as well as some possible future extensions of the present study.
{"title":"Thermal evolution of dark matter and gravitational-wave production in the early universe from a symplectic glueball model","authors":"Mattia Bruno, Niccolò Forzano, Marco Panero and Antonio Smecca","doi":"10.1088/1475-7516/2026/01/049","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/049","url":null,"abstract":"The hypothesis that dark matter could be a bound state of a strongly coupled non-Abelian gauge theory is theoretically appealing and has a variety of interesting phenomenological implications. In particular, an interpretation of dark matter as the lightest glueball state in the spectrum of a dark Yang-Mills theory, possibly coupled to the visible sector only through gravitational interactions, has been discussed quite extensively in the literature, but most of previous work has been focused on dark SU(N) gauge theories. In this article, we consider an alternative model, based on a symplectic gauge group, which has a first-order confinement/deconfinement phase transition at a finite critical temperature. We first determine the equation of state of this theory, focusing on temperatures close to the transition, and evaluating the associated latent heat. Then we discuss the evolution of this dark-matter model in the early universe, commenting on the mechanisms by which it could indirectly interact with the visible sector, on the spectrum of gravitational waves it could produce, and on the relic abundances it would lead to. Our discussion includes an extensive review of relevant literature, a number of comments on similarities and differences between our model and dark SU(N) gauge theories, as well as some possible future extensions of the present study.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"100 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044918","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}
Pub Date : 2026-01-26DOI: 10.1088/1475-7516/2026/01/048
David Brizuela, Marco de Cesare and Araceli Soler Oficial
We carry out a detailed analytical investigation of the propagation of gravitational waves in ghost-free bimetric gravity in a late-time de Sitter epoch. In this regime, the dynamical equations for the massless and massive graviton modes can be decoupled and solved exactly. We provide uniform approximations for the modes in terms of elementary functions, which are valid on all scales and for all viable mass windows. We identify different dynamical regimes for the system, depending on the propagation properties of the massive graviton, and whether the massless and massive components of the signal can be temporally resolved or not. In each regime, we compute the gravitational-wave luminosity distance as a function of redshift and study the propagation of wave packets. This allows for the derivation of a new observational bound for the ghost-free bimetric theory using the event GW170817. Further, by an explicit computation, we show that the massless and massive components of the signal retain their coherence also in the regime where they can be temporally resolved, even when couplings to incoherent matter degrees of freedom are included.
{"title":"Gravitational wave propagation in bigravity in the late universe","authors":"David Brizuela, Marco de Cesare and Araceli Soler Oficial","doi":"10.1088/1475-7516/2026/01/048","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/048","url":null,"abstract":"We carry out a detailed analytical investigation of the propagation of gravitational waves in ghost-free bimetric gravity in a late-time de Sitter epoch. In this regime, the dynamical equations for the massless and massive graviton modes can be decoupled and solved exactly. We provide uniform approximations for the modes in terms of elementary functions, which are valid on all scales and for all viable mass windows. We identify different dynamical regimes for the system, depending on the propagation properties of the massive graviton, and whether the massless and massive components of the signal can be temporally resolved or not. In each regime, we compute the gravitational-wave luminosity distance as a function of redshift and study the propagation of wave packets. This allows for the derivation of a new observational bound for the ghost-free bimetric theory using the event GW170817. Further, by an explicit computation, we show that the massless and massive components of the signal retain their coherence also in the regime where they can be temporally resolved, even when couplings to incoherent matter degrees of freedom are included.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"395 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044743","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}
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