Pub Date : 2025-12-18DOI: 10.1088/1475-7516/2025/12/044
Damiano F.G. Fiorillo, Federico Testagrossa, Chengchao Yuan, Maria Petropoulou and Walter Winter
High-energy gamma rays can trigger electromagnetic cascades via pair production on ambient photons, reprocessing their energy to lower frequencies. A classic example is the cascade from the gamma rays produced by ultra-high-energy cosmic rays in extragalactic photon fields, whose universal spectral shape was first described by Berezinsky in the 1970s. Recently, internal cascades, developing within the gamma-ray sources themselves, have gained a prominent role, as the IceCube data suggest that most detected neutrinos originate in gamma-ray-opaque environments. We analyze under what conditions these internal cascades can approach a universal spectrum. Since the Berezinsky treatment breaks down if synchrotron losses dominate, we present a generalized theory incorporating synchrotron-dominated cascades. We show the emergence of universal cascade spectrum among various examples of high-energy sources containing non-thermal cosmic rays, and discuss the conditions for its appearance.
{"title":"A generalized study of linear electromagnetic cascades in astrophysical sources","authors":"Damiano F.G. Fiorillo, Federico Testagrossa, Chengchao Yuan, Maria Petropoulou and Walter Winter","doi":"10.1088/1475-7516/2025/12/044","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/044","url":null,"abstract":"High-energy gamma rays can trigger electromagnetic cascades via pair production on ambient photons, reprocessing their energy to lower frequencies. A classic example is the cascade from the gamma rays produced by ultra-high-energy cosmic rays in extragalactic photon fields, whose universal spectral shape was first described by Berezinsky in the 1970s. Recently, internal cascades, developing within the gamma-ray sources themselves, have gained a prominent role, as the IceCube data suggest that most detected neutrinos originate in gamma-ray-opaque environments. We analyze under what conditions these internal cascades can approach a universal spectrum. Since the Berezinsky treatment breaks down if synchrotron losses dominate, we present a generalized theory incorporating synchrotron-dominated cascades. We show the emergence of universal cascade spectrum among various examples of high-energy sources containing non-thermal cosmic rays, and discuss the conditions for its appearance.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"5 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771087","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 : 2025-12-18DOI: 10.1088/1475-7516/2025/12/047
Gabriel Rodrigues, Antonio J. Cuesta, Jailson Alcaniz, Miguel Aparicio Resco, Antonio L. Maroto, Manuel Masip, Jamerson G. Rodrigues, Felipe B.M. dos Santos, Javier de Cruz Pérez, Jorge Enrique García-Farieta, Clarissa Siqueira, Fuxing Qin, Yuting Wang, Gong-Bo Zhao, Carlos Hernández-Monteagudo, Valerio Marra, Raul Abramo, Narciso Benítez, Silvia Bonoli, Saulo Carneiro, Javier Cenarro, David Cristóbal-Hornillos, Renato Dupke, Alessandro Ederoclite, Antonio Hernán-Caballero, Carlos López-Sanjuan, Antonio Marín-Franch, Claudia Mendes de Oliveira, Mariano Moles, Laerte Sodré, Keith Taylor, Jesús Varela and Héctor Vázquez Ramió
The large-scale structure survey J-PAS is taking data since October 2023. In this work, we present a forecast based on the Fisher matrix method to establish its sensitivity to the sum of the neutrino masses. We adapt the Fisher Galaxy Survey Code (FARO) to account for the neutrino mass under various configurations applied to galaxy clustering measurements. This approach allows us to test the sensitivity of J-PAS to the neutrino mass across different tracers, with and without non-linear corrections, and under varying sky coverage. We perform our forecast for two cosmological models: Λ CDM + ∑mν and w0waCDM + ∑mν. We combine our J-PAS forecast with Cosmic Microwave Background (CMB) data from the Planck Collaboration and Type Ia supernova (SN) data from Pantheon Plus. Our analysis shows that, for a sky coverage of 8,500 square degrees, J-PAS galaxy clustering data alone will constrain the sum of the neutrino masses to an upper limit at 95% C.L of ∑mν < 0.32 eV for the Λ CDM + ∑mν model, and ∑mν < 0.36 eV for the w0waCDM + ∑mν model. When combined with Planck data, the upper limit improves significantly. For J-PAS+Planck at 95% C.L, we find ∑mν < 0.061 eV for the Λ CDM + ∑mν model, and for J-PAS+Planck+Pantheon Plus, we obtain ∑mν < 0.12 eV for the w0waCDM + ∑mν model. These results demonstrate that J-PAS clustering measurements can play a crucial role in addressing challenges in the neutrino sector, including potential tensions between cosmological and terrestrial measurements of the neutrino mass, as well as in determining the mass ordering.
{"title":"J-PAS: forecasting constraints on neutrino masses","authors":"Gabriel Rodrigues, Antonio J. Cuesta, Jailson Alcaniz, Miguel Aparicio Resco, Antonio L. Maroto, Manuel Masip, Jamerson G. Rodrigues, Felipe B.M. dos Santos, Javier de Cruz Pérez, Jorge Enrique García-Farieta, Clarissa Siqueira, Fuxing Qin, Yuting Wang, Gong-Bo Zhao, Carlos Hernández-Monteagudo, Valerio Marra, Raul Abramo, Narciso Benítez, Silvia Bonoli, Saulo Carneiro, Javier Cenarro, David Cristóbal-Hornillos, Renato Dupke, Alessandro Ederoclite, Antonio Hernán-Caballero, Carlos López-Sanjuan, Antonio Marín-Franch, Claudia Mendes de Oliveira, Mariano Moles, Laerte Sodré, Keith Taylor, Jesús Varela and Héctor Vázquez Ramió","doi":"10.1088/1475-7516/2025/12/047","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/047","url":null,"abstract":"The large-scale structure survey J-PAS is taking data since October 2023. In this work, we present a forecast based on the Fisher matrix method to establish its sensitivity to the sum of the neutrino masses. We adapt the Fisher Galaxy Survey Code (FARO) to account for the neutrino mass under various configurations applied to galaxy clustering measurements. This approach allows us to test the sensitivity of J-PAS to the neutrino mass across different tracers, with and without non-linear corrections, and under varying sky coverage. We perform our forecast for two cosmological models: Λ CDM + ∑mν and w0waCDM + ∑mν. We combine our J-PAS forecast with Cosmic Microwave Background (CMB) data from the Planck Collaboration and Type Ia supernova (SN) data from Pantheon Plus. Our analysis shows that, for a sky coverage of 8,500 square degrees, J-PAS galaxy clustering data alone will constrain the sum of the neutrino masses to an upper limit at 95% C.L of ∑mν < 0.32 eV for the Λ CDM + ∑mν model, and ∑mν < 0.36 eV for the w0waCDM + ∑mν model. When combined with Planck data, the upper limit improves significantly. For J-PAS+Planck at 95% C.L, we find ∑mν < 0.061 eV for the Λ CDM + ∑mν model, and for J-PAS+Planck+Pantheon Plus, we obtain ∑mν < 0.12 eV for the w0waCDM + ∑mν model. These results demonstrate that J-PAS clustering measurements can play a crucial role in addressing challenges in the neutrino sector, including potential tensions between cosmological and terrestrial measurements of the neutrino mass, as well as in determining the mass ordering.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"21 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771090","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 : 2025-12-18DOI: 10.1088/1475-7516/2025/12/049
Alex González-Fuentes and Adrià Gómez-Valent
Scattered hints of dynamical dark energy (DE) have emerged in various contexts over the past decade. Recent observations from multiple supernova catalogs and the Dark Energy Spectroscopic Instrument (DESI), when combined with CMB data, suggest a highly non-trivial evolution of DE at the 2.5 -4σ CL. This evidence is typically quantified using the well-known Chevallier-Polarski-Linder (CPL) parametrization of the DE equation-of-state parameter, wDE, which corresponds to a first-order Taylor expansion of wDE(a) around a = 1. However, this truncation is to some extent arbitrary and may bias our interpretation of the data, potentially leading us to mistake spurious features of the best-fit CPL model for genuine physical properties of DE. In this work, we apply the Weighted Function Regression (WFR) method to eliminate the subjectivity associated with the choice of truncation order. We assign Bayesian weights to the various orders and compute weighted posterior distributions of the quantities of interest. Using this model-agnostic approach, we reconstruct some of the most relevant cosmological background quantities, namely wDE(z), the DE density ρDE(z), and several cosmographical functions, including the Hubble function H(z), the deceleration parameter q(z) and the jerk j(z). This allows us to identify which DE features are genuinely preferred by the data, rather than artifacts of a specific parametrization of wDE(z). We examine the robustness of our results against variations in the CMB and SNIa likelihoods. Furthermore, we extend our analysis by allowing for negative DE. Our results corroborate previous indications of dynamical DE reported in the literature, now confirmed for the first time using the WFR method. The combined analysis of CMB, BAO, and SNIa data favors an effective DE component that transitions from phantom to quintessence behavior at redshift zcross ∼ 0.4. The probability of phantom crossing lies between 96.21% and 99.97%, depending on the SNIa data set used, and hence a simple monotonic evolution of the DE density is excluded at the ∼ 2-4σ CL. Moreover, applying Occam's razor, we find no significant evidence for a negative dark energy density below z ∼ 2.5-3. Our reconstructions do not address the Hubble tension, yielding values of H0 consistent with the Planck/ΛCDM range. If SH0ES measurements are not affected by systematic biases, the evidence for dynamical dark energy may need to be reassessed.
{"title":"Reconstruction of dark energy and late-time cosmic expansion using the Weighted Function Regression method","authors":"Alex González-Fuentes and Adrià Gómez-Valent","doi":"10.1088/1475-7516/2025/12/049","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/049","url":null,"abstract":"Scattered hints of dynamical dark energy (DE) have emerged in various contexts over the past decade. Recent observations from multiple supernova catalogs and the Dark Energy Spectroscopic Instrument (DESI), when combined with CMB data, suggest a highly non-trivial evolution of DE at the 2.5 -4σ CL. This evidence is typically quantified using the well-known Chevallier-Polarski-Linder (CPL) parametrization of the DE equation-of-state parameter, wDE, which corresponds to a first-order Taylor expansion of wDE(a) around a = 1. However, this truncation is to some extent arbitrary and may bias our interpretation of the data, potentially leading us to mistake spurious features of the best-fit CPL model for genuine physical properties of DE. In this work, we apply the Weighted Function Regression (WFR) method to eliminate the subjectivity associated with the choice of truncation order. We assign Bayesian weights to the various orders and compute weighted posterior distributions of the quantities of interest. Using this model-agnostic approach, we reconstruct some of the most relevant cosmological background quantities, namely wDE(z), the DE density ρDE(z), and several cosmographical functions, including the Hubble function H(z), the deceleration parameter q(z) and the jerk j(z). This allows us to identify which DE features are genuinely preferred by the data, rather than artifacts of a specific parametrization of wDE(z). We examine the robustness of our results against variations in the CMB and SNIa likelihoods. Furthermore, we extend our analysis by allowing for negative DE. Our results corroborate previous indications of dynamical DE reported in the literature, now confirmed for the first time using the WFR method. The combined analysis of CMB, BAO, and SNIa data favors an effective DE component that transitions from phantom to quintessence behavior at redshift zcross ∼ 0.4. The probability of phantom crossing lies between 96.21% and 99.97%, depending on the SNIa data set used, and hence a simple monotonic evolution of the DE density is excluded at the ∼ 2-4σ CL. Moreover, applying Occam's razor, we find no significant evidence for a negative dark energy density below z ∼ 2.5-3. Our reconstructions do not address the Hubble tension, yielding values of H0 consistent with the Planck/ΛCDM range. If SH0ES measurements are not affected by systematic biases, the evidence for dynamical dark energy may need to be reassessed.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771092","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 : 2025-12-18DOI: 10.1088/1475-7516/2025/12/045
Paula S. Ferreira, Carlos Hernández-Monteagudo and Ribamar R.R. Reis
In this work we examine the baryon acoustic oscillations (BAO) in 2D angular and redshift space {θ, Δz}, with Δz denoting the redshift difference between two given angular shells. We thus work in the context of tomographic analyses of the large scale structure (LSS) where data are sliced in different redshift shells and constraints on Cosmology are extracted from the auto and cross-angular spectra of two different probes, namely the standard galaxy angular density fluctuations (ADF, or 2D clustering), and the galaxy angular redshift fluctuations (ARF). For these two observables we study by first time how the BAO peak arises in the {θ, Δz} plane. Despite being a weak feature (particularly for Δz ≠ 0), a Fisher forecast analysis shows that, a priori, most of the information on cosmological and galaxy bias parameters is carried by the BAO features in shell auto- and cross-angular power spectra. The same study shows that a joint probe analysis (ADF+ARF) increases the Fisher determinant associated to cosmological parameters such as H0 or the Dark Energy Chevallier-Polarski-Linder (CPL) parameters {w0,wa} by at least an order of magnitude. We also study how the Fisher information on cosmological and galaxy bias-related parameters behaves under different redshift shell configurations: including cross-correlations to neighbour shells extending up to (Δz)tot ∼ 0.6 ((Δz)tot ∼ 0.4) for ADF (ARF) is required for Fisher information to converge. At the same time, configurations using narrow shell widths (σz ≤ 0.02) preserve the cosmological information associated to peculiar velocities and typically yield Fisher determinants that are about two orders of magnitudes larger than for wider shell (σz > 0.02) configurations. In the context of upcoming surveys of the LSS like Euclid, DESI, Roman, J-PAS, LSST or CSST, these Fisher forecasts further motivate the tomographic use of pure angular anisotropies as an alternative approach to confront the cosmological predictions with observations, while providing a way to test consistency with standard 3D approaches to analyse LSS surveys.
{"title":"Baryon acoustic oscillations in tomographic angular density and redshift fluctuations","authors":"Paula S. Ferreira, Carlos Hernández-Monteagudo and Ribamar R.R. Reis","doi":"10.1088/1475-7516/2025/12/045","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/045","url":null,"abstract":"In this work we examine the baryon acoustic oscillations (BAO) in 2D angular and redshift space {θ, Δz}, with Δz denoting the redshift difference between two given angular shells. We thus work in the context of tomographic analyses of the large scale structure (LSS) where data are sliced in different redshift shells and constraints on Cosmology are extracted from the auto and cross-angular spectra of two different probes, namely the standard galaxy angular density fluctuations (ADF, or 2D clustering), and the galaxy angular redshift fluctuations (ARF). For these two observables we study by first time how the BAO peak arises in the {θ, Δz} plane. Despite being a weak feature (particularly for Δz ≠ 0), a Fisher forecast analysis shows that, a priori, most of the information on cosmological and galaxy bias parameters is carried by the BAO features in shell auto- and cross-angular power spectra. The same study shows that a joint probe analysis (ADF+ARF) increases the Fisher determinant associated to cosmological parameters such as H0 or the Dark Energy Chevallier-Polarski-Linder (CPL) parameters {w0,wa} by at least an order of magnitude. We also study how the Fisher information on cosmological and galaxy bias-related parameters behaves under different redshift shell configurations: including cross-correlations to neighbour shells extending up to (Δz)tot ∼ 0.6 ((Δz)tot ∼ 0.4) for ADF (ARF) is required for Fisher information to converge. At the same time, configurations using narrow shell widths (σz ≤ 0.02) preserve the cosmological information associated to peculiar velocities and typically yield Fisher determinants that are about two orders of magnitudes larger than for wider shell (σz > 0.02) configurations. In the context of upcoming surveys of the LSS like Euclid, DESI, Roman, J-PAS, LSST or CSST, these Fisher forecasts further motivate the tomographic use of pure angular anisotropies as an alternative approach to confront the cosmological predictions with observations, while providing a way to test consistency with standard 3D approaches to analyse LSS surveys.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"366 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771088","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 : 2025-12-18DOI: 10.1088/1475-7516/2025/12/042
Alfio M. Bonanno, Roman A. Konoplya, Giovanni Oglialoro and Andrea Spina
We derive a class of regular black holes from the proper-time renormalization group approach to asymptotically safe gravity. A central challenge is the robustness of physical predictions to the regularization scheme. We address this by computing key observables for our quantum-corrected black holes, which are non-singular and asymptotically Schwarzschild. We calculate the quasinormal mode spectrum, finding significant deviations from the classical case. The Hawking radiation spectrum is strongly suppressed, implying a slower evaporation rate and relaxed constraints on primordial black holes as dark matter. Shadows and ISCO radii remain consistent with observations. Our results demonstrate that the singularity resolution and its primary observational implications are robust physical outcomes.
{"title":"Regular black holes from proper-time flow in quantum gravity and their quasinormal modes, shadow and Hawking radiation","authors":"Alfio M. Bonanno, Roman A. Konoplya, Giovanni Oglialoro and Andrea Spina","doi":"10.1088/1475-7516/2025/12/042","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/042","url":null,"abstract":"We derive a class of regular black holes from the proper-time renormalization group approach to asymptotically safe gravity. A central challenge is the robustness of physical predictions to the regularization scheme. We address this by computing key observables for our quantum-corrected black holes, which are non-singular and asymptotically Schwarzschild. We calculate the quasinormal mode spectrum, finding significant deviations from the classical case. The Hawking radiation spectrum is strongly suppressed, implying a slower evaporation rate and relaxed constraints on primordial black holes as dark matter. Shadows and ISCO radii remain consistent with observations. Our results demonstrate that the singularity resolution and its primary observational implications are robust physical outcomes.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"31 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771083","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 : 2025-12-18DOI: 10.1088/1475-7516/2025/12/043
Aurel Schneider, Michael Kovač, Jozef Bucko, Andrina Nicola, Robert Reischke, Sambit K. Giri, Romain Teyssier, Tilman Tröster, Alexandre Refregier, Matthieu Schaller and Joop Schaye
We present an improved baryonification (BFC) model that modifies dark-matter-only N-body simulations to generate particle-level outputs for gas, dark matter, and stars. Unlike previous implementations, our approach first splits each simulation particle into separate dark matter and baryonic components, which are then displaced individually using the BFC technique. By applying the hydrostatic and ideal gas equations, we assign pressure and temperature values to individual gas particles. The model is validated against hydrodynamical simulations from the FLAMINGO and TNG suites (which feature varied feedback prescriptions) showing good agreement at the level of density and pressure profiles across a wide range of halo masses. As a further step, we calibrate the BFC model parameters to gas and stellar mass ratio profiles from the hydrodynamical simulations. Based on these calibrations, we baryonify N-body simulations and compare the resulting total matter power spectrum suppressions to the ones from the same hydrodynamical simulation. Carrying out this test of the BFC method at each redshift individually, we obtain a 2 percent agreement up to k = 5 h/Mpc across all tested feedback scenarios. We also define a reduced, 2+1 parameter BFC model that simultaneously accounts for feedback variations (2 parameters) and redshift evolution (1 parameter). The 2+1 parameter model agrees with the hydrodynamical simulations to better than 2.5 percent over the scales and redshifts relevant for cosmological surveys. Finally, we present a map-level comparison between a baryonified N-body simulation and a full hydrodynamical run from the TNG simulation suite. Visual inspection of dark matter, gas, and stellar density fields, along with the integrated pressure map, shows promising agreement. Further work is needed to quantify the accuracy at the level of observables. Overall, the new component-wise baryonification model offers a flexible and efficient framework for multi-probe cosmological studies.
{"title":"Baryonification: an alternative to hydrodynamical simulations for cosmological studies","authors":"Aurel Schneider, Michael Kovač, Jozef Bucko, Andrina Nicola, Robert Reischke, Sambit K. Giri, Romain Teyssier, Tilman Tröster, Alexandre Refregier, Matthieu Schaller and Joop Schaye","doi":"10.1088/1475-7516/2025/12/043","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/043","url":null,"abstract":"We present an improved baryonification (BFC) model that modifies dark-matter-only N-body simulations to generate particle-level outputs for gas, dark matter, and stars. Unlike previous implementations, our approach first splits each simulation particle into separate dark matter and baryonic components, which are then displaced individually using the BFC technique. By applying the hydrostatic and ideal gas equations, we assign pressure and temperature values to individual gas particles. The model is validated against hydrodynamical simulations from the FLAMINGO and TNG suites (which feature varied feedback prescriptions) showing good agreement at the level of density and pressure profiles across a wide range of halo masses. As a further step, we calibrate the BFC model parameters to gas and stellar mass ratio profiles from the hydrodynamical simulations. Based on these calibrations, we baryonify N-body simulations and compare the resulting total matter power spectrum suppressions to the ones from the same hydrodynamical simulation. Carrying out this test of the BFC method at each redshift individually, we obtain a 2 percent agreement up to k = 5 h/Mpc across all tested feedback scenarios. We also define a reduced, 2+1 parameter BFC model that simultaneously accounts for feedback variations (2 parameters) and redshift evolution (1 parameter). The 2+1 parameter model agrees with the hydrodynamical simulations to better than 2.5 percent over the scales and redshifts relevant for cosmological surveys. Finally, we present a map-level comparison between a baryonified N-body simulation and a full hydrodynamical run from the TNG simulation suite. Visual inspection of dark matter, gas, and stellar density fields, along with the integrated pressure map, shows promising agreement. Further work is needed to quantify the accuracy at the level of observables. Overall, the new component-wise baryonification model offers a flexible and efficient framework for multi-probe cosmological studies.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"12 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771086","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 : 2025-12-18DOI: 10.1088/1475-7516/2025/12/046
Pedro Bessa, Valerio Marra and Tiago Castro
Measurements of the redshift drift — the real time variation of the redshift of distance sources — are expected in the next couple of decades using next generation facilities such as the ANDES spectrograph at the ELT and the SKAO survey. The unprecedented precision of such observations will demand precise theoretical and numerical modeling of the effect in the standard ΛCDM cosmology. In this work, we use the Gadget4N-body code to simulate the redshift drift and its fluctuations in ΛCDM cosmologies, deriving the corresponding power spectra from a simulation with 10243 particles in a 1Gpc h-1 box. Our results represent an initial step toward deriving the redshift drift fluctuation power spectra from N-body simulations and establishing a methodology for the statistical analysis of the redshift drift effect using data from future large-scale surveys. However, further work is required to refine the approach and achieve an accurate modeling of the redshift drift fluctuation power spectra.
{"title":"Redshift drift fluctuations from N-body simulations","authors":"Pedro Bessa, Valerio Marra and Tiago Castro","doi":"10.1088/1475-7516/2025/12/046","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/046","url":null,"abstract":"Measurements of the redshift drift — the real time variation of the redshift of distance sources — are expected in the next couple of decades using next generation facilities such as the ANDES spectrograph at the ELT and the SKAO survey. The unprecedented precision of such observations will demand precise theoretical and numerical modeling of the effect in the standard ΛCDM cosmology. In this work, we use the Gadget4N-body code to simulate the redshift drift and its fluctuations in ΛCDM cosmologies, deriving the corresponding power spectra from a simulation with 10243 particles in a 1Gpc h-1 box. Our results represent an initial step toward deriving the redshift drift fluctuation power spectra from N-body simulations and establishing a methodology for the statistical analysis of the redshift drift effect using data from future large-scale surveys. However, further work is required to refine the approach and achieve an accurate modeling of the redshift drift fluctuation power spectra.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"5 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771089","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 : 2025-12-18DOI: 10.1088/1475-7516/2025/12/048
Tian-Nuo Li, Yi-Min Zhang, Yan-Hong Yao, Guo-Hong Du, Peng-Ju Wu, Jing-Fei Zhang and Xin Zhang
The nature of dark matter remains one of the most fundamental and unresolved questions in modern cosmology. In most cosmological models, dark matter is typically modeled as pressureless dust with an equation of state (EoS) parameter wdm = 0. However, there is no fundamental theoretical reason to exclude the possibility of a non-zero dark matter EoS parameter. In this work, we explore the possibility of a non-zero dark matter EoS within the phenomenologically emergent dark energy (PEDE) model, given its simplicity and proven ability to alleviate the Hubble tension. We perform observational constraints by using the latest baryon acoustic oscillation data from DESI DR2, the cosmic microwave background (CMB) data from Planck, and the type Ia supernova data from DESY5 and PantheonPlus. From our analysis, we observe that a negative dark matter EoS parameter is preferred in all scenarios. Specifically, the CMB+DESI+DESY5 data yields wdm = -0.00093 ± 0.00032, deviating from zero at approximately the 3σ level. However, this deviation is likely driven by unidentified systematics or inconsistencies in the DESY5 data, with the deviation decreasing to 2σ when using PantheonPlus data. Meanwhile, a negative wdm would increase the Hubble tension due to the positive degeneracy between wdm and H0. Furthermore, Bayesian evidence suggests that the ΛCDM model is strongly preferred over the PEDE+w_ dm model. These analyses illustrate that it is not possible to both support a non-zero dark matter component within the PEDE model and alleviate the Hubble tension simultaneously.
{"title":"Revisiting the phenomenologically emergent dark energy model: is non-zero equation of state of dark matter favored by DESI DR2?","authors":"Tian-Nuo Li, Yi-Min Zhang, Yan-Hong Yao, Guo-Hong Du, Peng-Ju Wu, Jing-Fei Zhang and Xin Zhang","doi":"10.1088/1475-7516/2025/12/048","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/048","url":null,"abstract":"The nature of dark matter remains one of the most fundamental and unresolved questions in modern cosmology. In most cosmological models, dark matter is typically modeled as pressureless dust with an equation of state (EoS) parameter wdm = 0. However, there is no fundamental theoretical reason to exclude the possibility of a non-zero dark matter EoS parameter. In this work, we explore the possibility of a non-zero dark matter EoS within the phenomenologically emergent dark energy (PEDE) model, given its simplicity and proven ability to alleviate the Hubble tension. We perform observational constraints by using the latest baryon acoustic oscillation data from DESI DR2, the cosmic microwave background (CMB) data from Planck, and the type Ia supernova data from DESY5 and PantheonPlus. From our analysis, we observe that a negative dark matter EoS parameter is preferred in all scenarios. Specifically, the CMB+DESI+DESY5 data yields wdm = -0.00093 ± 0.00032, deviating from zero at approximately the 3σ level. However, this deviation is likely driven by unidentified systematics or inconsistencies in the DESY5 data, with the deviation decreasing to 2σ when using PantheonPlus data. Meanwhile, a negative wdm would increase the Hubble tension due to the positive degeneracy between wdm and H0. Furthermore, Bayesian evidence suggests that the ΛCDM model is strongly preferred over the PEDE+w_ dm model. These analyses illustrate that it is not possible to both support a non-zero dark matter component within the PEDE model and alleviate the Hubble tension simultaneously.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"153 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771091","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 : 2025-12-17DOI: 10.1088/1475-7516/2025/12/040
Sergei V. Ketov, Ekaterina O. Pozdeeva and Sergey Yu. Vernov
The F(R) gravity models of inflation are revisited in light of the recent observations of cosmic microwave background radiation by Atacama Cosmology Telescope (ACT) and DESI Collaboration. A detailed study of the evolution equations in the Jordan frame is given and a new description of the slow-roll approximation in the F(R)-gravity-based models of inflation is proposed. It is found that all those models of inflation are significantly constrained by demanding a higher (than the Planck Telescope value) cosmological tilt ns of scalar perturbations and a positive running index αs favored by ACT. It is not difficult to meet the ACT constraints on the scalar tilt ns by modifying the existing models of inflation, but simultaneously demanding a positive running αs would rule out many of them. Using the proposed slow-roll approximation in the Jordan frame, we provide a new modification of the Starobinsky inflation model in the framework of F(R) gravity, which satisfies all ACT constraints. An extension of our ACT-consistent inflation model to the unified F(R)-gravity description of Starobinsky-like inflation and production of primordial black holes on a smaller scale is also proposed.
{"title":"Inflation in F(R) gravity models revisited after ACT","authors":"Sergei V. Ketov, Ekaterina O. Pozdeeva and Sergey Yu. Vernov","doi":"10.1088/1475-7516/2025/12/040","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/040","url":null,"abstract":"The F(R) gravity models of inflation are revisited in light of the recent observations of cosmic microwave background radiation by Atacama Cosmology Telescope (ACT) and DESI Collaboration. A detailed study of the evolution equations in the Jordan frame is given and a new description of the slow-roll approximation in the F(R)-gravity-based models of inflation is proposed. It is found that all those models of inflation are significantly constrained by demanding a higher (than the Planck Telescope value) cosmological tilt ns of scalar perturbations and a positive running index αs favored by ACT. It is not difficult to meet the ACT constraints on the scalar tilt ns by modifying the existing models of inflation, but simultaneously demanding a positive running αs would rule out many of them. Using the proposed slow-roll approximation in the Jordan frame, we provide a new modification of the Starobinsky inflation model in the framework of F(R) gravity, which satisfies all ACT constraints. An extension of our ACT-consistent inflation model to the unified F(R)-gravity description of Starobinsky-like inflation and production of primordial black holes on a smaller scale is also proposed.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"29 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771093","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 : 2025-12-17DOI: 10.1088/1475-7516/2025/12/041
Pedro De La Torre Luque, Daniele Gaggero, Dario Grasso, Antonio Marinelli and Manuel Rocamora
The LHAASO collaboration has recently released the spectrum and the angular distribution of the γ-ray Galactic diffuse emission from 1 TeV to 1 PeV measured with the Kilometer-2 Array (KM2A) and Water Cherenkov Detector Array (WCDA). We show that these data are in remarkably good agreement with a set of models that assume the emission to be produced by the Galactic population of cosmic rays if its spectral shape traces that measured by CALET and DAMPE as well as KASCADE at higher energies. No extra-components besides the CR sea is needed to explain LHAASO results. Accounting for unresolved sources, we consistently reproduce a wide set of γ-ray data at lower energy. To do this, we consider two different transport setups: a conventional one and a γ-optimized spatial-dependent one (a development of the widely adopted KRA_γ model). We demonstrate that both setups are compatible with LHAASO results. However, the latter is preferred if one takes into account Fermi-LAT gamma-ray data and neutrino measurements. In fact, we also compute the associated Galactic neutrino diffuse emission finding that the contribution from sources cannot be dominant and showing that spatial-dependent propagation models closely match the ANTARES and IceCube best fits for the Galactic Center Ridge and the Galactic Plane emissions. We argue that our γ-optimized model should be used as a template for future analyses of upcoming data from the Global Neutrino Network.
{"title":"The cosmic-ray sea explains the diffuse galactic gamma-ray and neutrino emissions from GeV to PeV","authors":"Pedro De La Torre Luque, Daniele Gaggero, Dario Grasso, Antonio Marinelli and Manuel Rocamora","doi":"10.1088/1475-7516/2025/12/041","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/12/041","url":null,"abstract":"The LHAASO collaboration has recently released the spectrum and the angular distribution of the γ-ray Galactic diffuse emission from 1 TeV to 1 PeV measured with the Kilometer-2 Array (KM2A) and Water Cherenkov Detector Array (WCDA). We show that these data are in remarkably good agreement with a set of models that assume the emission to be produced by the Galactic population of cosmic rays if its spectral shape traces that measured by CALET and DAMPE as well as KASCADE at higher energies. No extra-components besides the CR sea is needed to explain LHAASO results. Accounting for unresolved sources, we consistently reproduce a wide set of γ-ray data at lower energy. To do this, we consider two different transport setups: a conventional one and a γ-optimized spatial-dependent one (a development of the widely adopted KRA_γ model). We demonstrate that both setups are compatible with LHAASO results. However, the latter is preferred if one takes into account Fermi-LAT gamma-ray data and neutrino measurements. In fact, we also compute the associated Galactic neutrino diffuse emission finding that the contribution from sources cannot be dominant and showing that spatial-dependent propagation models closely match the ANTARES and IceCube best fits for the Galactic Center Ridge and the Galactic Plane emissions. We argue that our γ-optimized model should be used as a template for future analyses of upcoming data from the Global Neutrino Network.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"17 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771151","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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