Pub Date : 2026-01-28DOI: 10.1088/1475-7516/2026/01/054
Neel Shah, Kazuya Koyama and Johannes Noller
In order to derive model-independent observational bounds on dark energy/modified gravity theories, a typical approach is to constrain parametrised models intended to capture the space of dark energy theories. Here we investigate in detail the effect that the nature of these parametrisations can have, finding significant effects on the resulting cosmological dark energy constraints. In order to observationally distinguish well-motivated and physical parametrisations from unphysical ones, it is crucial to understand the theoretical priors that physical parametrisations place on the phenomenology of dark energy. To this end we discuss a range of theoretical priors that can be imposed on general dark energy parametrisations, and their effect on the constraints on the phenomenology of dynamical dark energy. More specifically, we investigate both the phenomenological {μ,Σ} parametrisation as well as effective field theory (EFT) inspired approaches to model dark energy interactions. We compare the constraints obtained in both approaches for different phenomenological and theory-informed time dependences for the underlying functional degrees of freedom, discuss the effects of priors derived from gravitational wave physics, and investigate the interplay between constraints on parameters constraining only the background evolution vs. parameters controlling linear perturbations.
{"title":"Dark energy constraints in light of theoretical priors","authors":"Neel Shah, Kazuya Koyama and Johannes Noller","doi":"10.1088/1475-7516/2026/01/054","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/054","url":null,"abstract":"In order to derive model-independent observational bounds on dark energy/modified gravity theories, a typical approach is to constrain parametrised models intended to capture the space of dark energy theories. Here we investigate in detail the effect that the nature of these parametrisations can have, finding significant effects on the resulting cosmological dark energy constraints. In order to observationally distinguish well-motivated and physical parametrisations from unphysical ones, it is crucial to understand the theoretical priors that physical parametrisations place on the phenomenology of dark energy. To this end we discuss a range of theoretical priors that can be imposed on general dark energy parametrisations, and their effect on the constraints on the phenomenology of dynamical dark energy. More specifically, we investigate both the phenomenological {μ,Σ} parametrisation as well as effective field theory (EFT) inspired approaches to model dark energy interactions. We compare the constraints obtained in both approaches for different phenomenological and theory-informed time dependences for the underlying functional degrees of freedom, discuss the effects of priors derived from gravitational wave physics, and investigate the interplay between constraints on parameters constraining only the background evolution vs. parameters controlling linear perturbations.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"15 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057068","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 : 2026-01-28DOI: 10.1088/1475-7516/2026/01/058
Daniela S.J. Cordeiro, Ednaldo L.B. Junior, José Tarciso S.S. Junior, Francisco S.N. Lobo, Jorde A.A. Ramos, Manuel E. Rodrigues, Luís F. Dias da Silva and Henrique A. Vieira
Black-bounce (BB) solutions generalize the spacetimes of black holes, regular black holes, and wormholes, depending on the values of certain characteristic parameters. In this work, we investigate such solutions within the framework of General Relativity (GR), assuming spherical symmetry and static geometry. It is well established in the literature that, in order to sustain such geometries, the source of Einstein's equations in the BB context can be composed of a scalar field φ and a nonlinear electrodynamics (NLED). In our model, in addition to the Lagrangian associated with the scalar field in the action, we also include an interaction term of the form W(φ)ℒ(F), which introduces a nonminimal coupling between the scalar field and the electromagnetic sector. Notably, the usual minimal coupling configuration is recovered by setting W(φ) = 1. In contrast to approaches where the function W(φ) is assumed a priori, here we determine its functional form by modeling the radial dependence of the derivative of the electromagnetic Lagrangian as a power law, namely ℒF(r) ∼ Fn. This approach enables us to determine W(r) directly from the obtained solutions. We apply this procedure to two specific geometries: the Simpson-Visser-type BB solution and the Bardeen-type BB solution, both analyzed in the purely magnetic (qm ≠ 0, qe = 0) and purely electric (qm = 0, qe ≠ 0) cases. In all scenarios, we find that these BB spacetime solutions can be described with a linear electrodynamics, which is a noteworthy result. Furthermore, we examine the regularity of the spacetime through the Kretschmann scalar and briefly discuss the associated energy conditions for the solutions obtained.
{"title":"Black bounce solutions via nonminimal scalar-electrodynamic couplings","authors":"Daniela S.J. Cordeiro, Ednaldo L.B. Junior, José Tarciso S.S. Junior, Francisco S.N. Lobo, Jorde A.A. Ramos, Manuel E. Rodrigues, Luís F. Dias da Silva and Henrique A. Vieira","doi":"10.1088/1475-7516/2026/01/058","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/058","url":null,"abstract":"Black-bounce (BB) solutions generalize the spacetimes of black holes, regular black holes, and wormholes, depending on the values of certain characteristic parameters. In this work, we investigate such solutions within the framework of General Relativity (GR), assuming spherical symmetry and static geometry. It is well established in the literature that, in order to sustain such geometries, the source of Einstein's equations in the BB context can be composed of a scalar field φ and a nonlinear electrodynamics (NLED). In our model, in addition to the Lagrangian associated with the scalar field in the action, we also include an interaction term of the form W(φ)ℒ(F), which introduces a nonminimal coupling between the scalar field and the electromagnetic sector. Notably, the usual minimal coupling configuration is recovered by setting W(φ) = 1. In contrast to approaches where the function W(φ) is assumed a priori, here we determine its functional form by modeling the radial dependence of the derivative of the electromagnetic Lagrangian as a power law, namely ℒF(r) ∼ Fn. This approach enables us to determine W(r) directly from the obtained solutions. We apply this procedure to two specific geometries: the Simpson-Visser-type BB solution and the Bardeen-type BB solution, both analyzed in the purely magnetic (qm ≠ 0, qe = 0) and purely electric (qm = 0, qe ≠ 0) cases. In all scenarios, we find that these BB spacetime solutions can be described with a linear electrodynamics, which is a noteworthy result. Furthermore, we examine the regularity of the spacetime through the Kretschmann scalar and briefly discuss the associated energy conditions for the solutions obtained.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"15 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057072","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 : 2026-01-28DOI: 10.1088/1475-7516/2026/01/053
Alvin Leluc, Joel Meyers and Alexander van Engelen
Gravitational waves (GWs) passing through the Earth cause a correlated pattern of time-dependent deflections of the apparent position of astronomical sources. We build upon standard lensing reconstruction techniques to develop a new time-dependent optimal quadratic estimator, providing a novel technique to search for the deflections produced by GWs using observations of the cosmic microwave background (CMB). We find that the time-dependent deflection reconstruction is many orders of magnitude more sensitive than the ordinary static lensing estimator, and that it can be employed with the data collected by existing and future CMB surveys, without requiring any modification to the experimental or survey design. We demonstrate that CMB surveys offer sensitivity to GWs across a broad frequency range: while the sensitivity will not be competitive over the frequency range covered by pulsar timing arrays, the coverage band extend to both lower and higher frequencies. Finally, we discuss how our methods can be adapted to search for other time-varying signals, and also how they can be applied to surveys at other wavelengths.
{"title":"Time-dependent deflection reconstruction: new technique to search for gravitational waves with the cosmic microwave background","authors":"Alvin Leluc, Joel Meyers and Alexander van Engelen","doi":"10.1088/1475-7516/2026/01/053","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/053","url":null,"abstract":"Gravitational waves (GWs) passing through the Earth cause a correlated pattern of time-dependent deflections of the apparent position of astronomical sources. We build upon standard lensing reconstruction techniques to develop a new time-dependent optimal quadratic estimator, providing a novel technique to search for the deflections produced by GWs using observations of the cosmic microwave background (CMB). We find that the time-dependent deflection reconstruction is many orders of magnitude more sensitive than the ordinary static lensing estimator, and that it can be employed with the data collected by existing and future CMB surveys, without requiring any modification to the experimental or survey design. We demonstrate that CMB surveys offer sensitivity to GWs across a broad frequency range: while the sensitivity will not be competitive over the frequency range covered by pulsar timing arrays, the coverage band extend to both lower and higher frequencies. Finally, we discuss how our methods can be adapted to search for other time-varying signals, and also how they can be applied to surveys at other wavelengths.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"30 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057067","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 : 2026-01-28DOI: 10.1088/1475-7516/2026/01/057
Rodrigo Calderón, Théo Simon, Arman Shafieloo and Dhiraj Kumar Hazra
While the simplest inflationary models predict a power-law form of the primordial power spectrum (PPS), various UV complete scenarios predict features on top of the standard power law that leave characteristic imprints in the late-time distribution of matter, encoded in the galaxy power spectrum. In this work, we assess the validity of the Effective Field Theory of Large Scale Structure (EFTofLSS) and the IR-resummation scheme of PyBird in the context of primordial (oscillatory) features. We find an excellent agreement at the level of the matter power spectrum between N-body simulations and the one-loop EFT predictions, for models commonly studied in the literature. We then apply the EFTofLSS to the galaxy power spectrum measurements from BOSS LRG and eBOSS QSO to constrain specific global and local features in the PPS. We demonstrate that while such features can improve the fit to cosmic microwave background (CMB) data, they may result in a poorer fit to clustering measurements at low redshift. The resulting constraints on the amplitude of the primordial oscillations are competitive with those obtained from CMB data, despite the well-known damping of oscillations due to non-linear structure formation processes. For the first time in this context, we jointly analyze the galaxy power spectrum (monopole and quadrupole) in combination with Planck CMB data to derive strong constraints on the amplitude of primordial features. This work highlights the EFTofLSS as a powerful tool for testing early universe scenarios on scales that complement CMB observations.
{"title":"Primordial features in light of the Effective Field Theory of Large-Scale Structure","authors":"Rodrigo Calderón, Théo Simon, Arman Shafieloo and Dhiraj Kumar Hazra","doi":"10.1088/1475-7516/2026/01/057","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/057","url":null,"abstract":"While the simplest inflationary models predict a power-law form of the primordial power spectrum (PPS), various UV complete scenarios predict features on top of the standard power law that leave characteristic imprints in the late-time distribution of matter, encoded in the galaxy power spectrum. In this work, we assess the validity of the Effective Field Theory of Large Scale Structure (EFTofLSS) and the IR-resummation scheme of PyBird in the context of primordial (oscillatory) features. We find an excellent agreement at the level of the matter power spectrum between N-body simulations and the one-loop EFT predictions, for models commonly studied in the literature. We then apply the EFTofLSS to the galaxy power spectrum measurements from BOSS LRG and eBOSS QSO to constrain specific global and local features in the PPS. We demonstrate that while such features can improve the fit to cosmic microwave background (CMB) data, they may result in a poorer fit to clustering measurements at low redshift. The resulting constraints on the amplitude of the primordial oscillations are competitive with those obtained from CMB data, despite the well-known damping of oscillations due to non-linear structure formation processes. For the first time in this context, we jointly analyze the galaxy power spectrum (monopole and quadrupole) in combination with Planck CMB data to derive strong constraints on the amplitude of primordial features. This work highlights the EFTofLSS as a powerful tool for testing early universe scenarios on scales that complement CMB observations.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"24 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057071","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 : 2026-01-28DOI: 10.1088/1475-7516/2026/01/061
Miguel Barroso Varela, Orfeu Bertolami and Andreas Mantziris
This study examines how inflationary dynamics are affected by f(R)-theories with a non-minimal coupling between matter and curvature. Both positive and negative corrections to the minimal coupling of General Relativity are considered, and a robust numerical method is developed that evolves the metric and the inflaton field in this modified theory beyond slow-roll. Through a stability analysis, we find that positive models are inherently unstable during slow-roll, whereas negative ones can accommodate a stable attractor de Sitter solution. Using the amplitude of the scalar power spectrum from the latest data releases, we constrain the scale of the non-minimal coupling to be above 1013 GeV. In light of the 2018 Planck, BICEP/Keck and the recent Atacama Cosmology Telescope data for the scalar spectral index and tensor-to-scalar ratio, strong constraints on the coupling strength force the effects of these modified theories to be, at most, slightly above the perturbative level. Furthermore, we determine that the choice of the perfect fluid matter Lagrangian does not impact the inflationary observables at the pivot scale. Finally, we present the predicted observables for different inflationary potentials and show that even though classical gravity is still preferred by the data, there are areas of the parameter space that are viable for non-minimally coupled inflationary models.
{"title":"Inflationary dynamics of non-minimally coupled f(R) matter-curvature theories","authors":"Miguel Barroso Varela, Orfeu Bertolami and Andreas Mantziris","doi":"10.1088/1475-7516/2026/01/061","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/061","url":null,"abstract":"This study examines how inflationary dynamics are affected by f(R)-theories with a non-minimal coupling between matter and curvature. Both positive and negative corrections to the minimal coupling of General Relativity are considered, and a robust numerical method is developed that evolves the metric and the inflaton field in this modified theory beyond slow-roll. Through a stability analysis, we find that positive models are inherently unstable during slow-roll, whereas negative ones can accommodate a stable attractor de Sitter solution. Using the amplitude of the scalar power spectrum from the latest data releases, we constrain the scale of the non-minimal coupling to be above 1013 GeV. In light of the 2018 Planck, BICEP/Keck and the recent Atacama Cosmology Telescope data for the scalar spectral index and tensor-to-scalar ratio, strong constraints on the coupling strength force the effects of these modified theories to be, at most, slightly above the perturbative level. Furthermore, we determine that the choice of the perfect fluid matter Lagrangian does not impact the inflationary observables at the pivot scale. Finally, we present the predicted observables for different inflationary potentials and show that even though classical gravity is still preferred by the data, there are areas of the parameter space that are viable for non-minimally coupled inflationary models.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057075","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 : 2026-01-28DOI: 10.1088/1475-7516/2026/01/060
Hamza Rehman, Saddam Hussain, Ghulam Abbas and Tao Zhu
This paper investigates the influence of the dimensionless electric charge (Q/M), magnetic charge (P/M), and Taub-NUT parameter (n/M) of a dyonic Kerr-Newman-Kasuya-Taub-NUT black hole on quasi-periodic oscillations (QPOs) observed in X-ray binaries. Using the relativistic precession model, we calculate the three fundamental frequencies arising from particle motion in the accretion disk around the black hole. These theoretical predictions are then confronted with observational QPO data from five X-ray binaries (GRO J1655–40, XTE J1859+226, XTE J1550–564, GRS 1915+105, and H1743–322), and the Markov Chain Monte Carlo technique is used to constrain the black hole parameters. Our analysis reveals no significant evidence for nonzero values of Q/M and P/M across all sources, thereby allowing us to place several stringent upper limits on electric charge (Q/M) and magnetic charge (P/M) of the black hole in these systems. Similarly, no compelling indication of a nonzero Taub-NUT parameter is found in QPOs from GRO J1655–40, XTE J1859+226, XTE J1550–564, and H1743–322. In contrast, the posterior distribution derived from GRS 1915+105 data suggests a nonzero Taub-NUT parameter, i.e., gravitomagnetic monopole moment. This result indicates a potential deviation from the Kerr metric in this astrophysical black hole.
{"title":"Constraints on extra charges in dyonic Kerr-Newman-Kasuya-Taub-NUT black hole from the observations of quasi-periodic oscillations","authors":"Hamza Rehman, Saddam Hussain, Ghulam Abbas and Tao Zhu","doi":"10.1088/1475-7516/2026/01/060","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/060","url":null,"abstract":"This paper investigates the influence of the dimensionless electric charge (Q/M), magnetic charge (P/M), and Taub-NUT parameter (n/M) of a dyonic Kerr-Newman-Kasuya-Taub-NUT black hole on quasi-periodic oscillations (QPOs) observed in X-ray binaries. Using the relativistic precession model, we calculate the three fundamental frequencies arising from particle motion in the accretion disk around the black hole. These theoretical predictions are then confronted with observational QPO data from five X-ray binaries (GRO J1655–40, XTE J1859+226, XTE J1550–564, GRS 1915+105, and H1743–322), and the Markov Chain Monte Carlo technique is used to constrain the black hole parameters. Our analysis reveals no significant evidence for nonzero values of Q/M and P/M across all sources, thereby allowing us to place several stringent upper limits on electric charge (Q/M) and magnetic charge (P/M) of the black hole in these systems. Similarly, no compelling indication of a nonzero Taub-NUT parameter is found in QPOs from GRO J1655–40, XTE J1859+226, XTE J1550–564, and H1743–322. In contrast, the posterior distribution derived from GRS 1915+105 data suggests a nonzero Taub-NUT parameter, i.e., gravitomagnetic monopole moment. This result indicates a potential deviation from the Kerr metric in this astrophysical black hole.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"38 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057074","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: 10.1088/1475-7516/2026/01/045
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}
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