Pub Date : 2026-01-21DOI: 10.1088/1475-7516/2026/01/031
Meagan Herbold, Naim Göksel Karaçaylı and Paul Martini
The one-dimensional flux power spectrum (P1D) of the Lyman-α forest probes small-scale structure in the intergalactic medium (IGM) and is therefore sensitive to a variety of cosmological and astrophysical parameters. These include the amplitude and shape of the matter power spectrum, the thermal history of the IGM, the sum of neutrino masses, and potential small-scale fluctuations due to the nature of dark matter. However, P1D is also highly sensitive to observational and instrumental systematics, making accurate synthetic spectra essential for validating analyses and quantifying these effects, especially in high-volume surveys like the Dark Energy Spectroscopic Instrument (DESI). We present an efficient lognormal mock framework for generating one-dimensional Lyman-α forest spectra tailored for P1D analysis. Our method captures the redshift evolution of the mean transmitted flux and the scale-dependent shape and amplitude of the one-dimensional flux power spectrum by tuning Gaussian field correlations and transformation parameters. Across the DESI Early Data Release (EDR) redshift range (2.0 ≤ z ≤ 3.8), and a wide range of scales (10-4 s km-1 ≤ k ≤ 1.0 s km-1), our mocks recover the mean flux evolution with redshift to sub-percent accuracy, and the P1D at the percent level. Additionally, we discuss potential extensions of this framework, such as the incorporation of astrophysical contaminants, continuum uncertainties, and instrumental effects. Such improvements would expand its utility in ongoing and upcoming surveys and enable a broader range of validation efforts and systematics studies for P1D inference and precision cosmology.
Lyman-α森林的一维通量功率谱（P1D）探测了星系间介质（IGM）中的小尺度结构，因此对各种宇宙学和天体物理参数都很敏感。这些包括物质功率谱的振幅和形状，IGM的热历史，中微子质量的总和，以及由于暗物质的性质而产生的潜在的小尺度波动。然而，P1D对观测和仪器系统也高度敏感，这使得精确的合成光谱对于验证分析和量化这些效应至关重要，特别是在像暗能量光谱仪器（DESI）这样的大容量调查中。我们提出了一个有效的对数正态模拟框架，用于生成适合P1D分析的一维Lyman-α森林光谱。该方法通过调整高斯场相关系数和变换参数，捕捉平均透射通量的红移演化和一维通量功率谱的尺度相关形状和振幅。在DESI早期数据发布（EDR）的红移范围（2.0≤z≤3.8）和较宽的尺度范围（10-4 s km-1≤k≤1.0 s km-1）内，我们的模拟将平均通量演化的红移精度恢复到亚百分比，P1D恢复到百分比水平。此外，我们还讨论了这一框架的潜在扩展，如天体物理污染物、连续体不确定性和仪器效应的结合。这些改进将扩大其在正在进行和即将进行的调查中的效用，并为P1D推理和精确宇宙学提供更广泛的验证工作和系统学研究。
{"title":"Generation of lognormal synthetic Lyman-α forest spectra for P1D analysis","authors":"Meagan Herbold, Naim Göksel Karaçaylı and Paul Martini","doi":"10.1088/1475-7516/2026/01/031","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/031","url":null,"abstract":"The one-dimensional flux power spectrum (P1D) of the Lyman-α forest probes small-scale structure in the intergalactic medium (IGM) and is therefore sensitive to a variety of cosmological and astrophysical parameters. These include the amplitude and shape of the matter power spectrum, the thermal history of the IGM, the sum of neutrino masses, and potential small-scale fluctuations due to the nature of dark matter. However, P1D is also highly sensitive to observational and instrumental systematics, making accurate synthetic spectra essential for validating analyses and quantifying these effects, especially in high-volume surveys like the Dark Energy Spectroscopic Instrument (DESI). We present an efficient lognormal mock framework for generating one-dimensional Lyman-α forest spectra tailored for P1D analysis. Our method captures the redshift evolution of the mean transmitted flux and the scale-dependent shape and amplitude of the one-dimensional flux power spectrum by tuning Gaussian field correlations and transformation parameters. Across the DESI Early Data Release (EDR) redshift range (2.0 ≤ z ≤ 3.8), and a wide range of scales (10-4 s km-1 ≤ k ≤ 1.0 s km-1), our mocks recover the mean flux evolution with redshift to sub-percent accuracy, and the P1D at the percent level. Additionally, we discuss potential extensions of this framework, such as the incorporation of astrophysical contaminants, continuum uncertainties, and instrumental effects. Such improvements would expand its utility in ongoing and upcoming surveys and enable a broader range of validation efforts and systematics studies for P1D inference and precision cosmology.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"12 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006169","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 : 2026-01-21DOI: 10.1088/1475-7516/2026/01/028
TaeHun Kim, Philip Lu and Volodymyr Takhistov
We present the first unified constraints on a broad class of extended dark matter compact objects (EDCOs) from interstellar gas heating. These include axion stars, Q-balls, axion miniclusters, dark fermion stars and primordial black holes surrounded by dark matter halos, which arise in a wide range of theories beyond the Standard Model. As such massive objects traverse the interstellar medium, their gravitational influence generates wakes and, if sufficiently compact, drives accretion flows that heat gas in their vicinity. Our general framework extends standard dynamical friction treatments by incorporating finite-size effects, internal density profiles, gas penetration through objects, and criteria for accretion disk formation. We perform detailed numerical calculations of wake formation and gas heating and apply our results to the Leo T dwarf galaxy, establishing new constraints on the dark matter fraction in EDCOs heavier than a solar mass spanning several orders of magnitude in both mass and abundance.
{"title":"Unified gas heating constraints on extended dark matter compact objects","authors":"TaeHun Kim, Philip Lu and Volodymyr Takhistov","doi":"10.1088/1475-7516/2026/01/028","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/028","url":null,"abstract":"We present the first unified constraints on a broad class of extended dark matter compact objects (EDCOs) from interstellar gas heating. These include axion stars, Q-balls, axion miniclusters, dark fermion stars and primordial black holes surrounded by dark matter halos, which arise in a wide range of theories beyond the Standard Model. As such massive objects traverse the interstellar medium, their gravitational influence generates wakes and, if sufficiently compact, drives accretion flows that heat gas in their vicinity. Our general framework extends standard dynamical friction treatments by incorporating finite-size effects, internal density profiles, gas penetration through objects, and criteria for accretion disk formation. We perform detailed numerical calculations of wake formation and gas heating and apply our results to the Leo T dwarf galaxy, establishing new constraints on the dark matter fraction in EDCOs heavier than a solar mass spanning several orders of magnitude in both mass and abundance.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"88 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006166","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 : 2026-01-21DOI: 10.1088/1475-7516/2026/01/027
Kumiko Kotera, Mainak Mukhopadhyay, Rafael Alves Batista, Derek Fox, Olivier Martineau-Huynh, Kohta Murase, Stephanie Wissel and Andrew Zeolla
Detecting ultrahigh-energy neutrinos can take two complementary approaches with different trade-offs. 1) Wide and shallow: aim for the largest effective volume, and to be cost-effective, go for wide field-of-view but at the cost of a shallow instantaneous sensitivity — this is less complex conceptually, and has strong discovery potential for serendipitous events. However, it is unclear if any source can be identified, following detection. And 2) Deep and narrow: here one uses astrophysical and multi-messenger information to target the most likely sources and populations that could emit neutrinos — these instruments have deep instantaneous sensitivity albeit a narrow field of view. Such an astrophysically-motivated approach provides higher chances for detection of known/observed source classes, and ensures multi-messenger astronomy. However, it has less potential for serendipitous discoveries. In light of the recent progress in multi-messenger and time-domain astronomy, we assess the power of the deep and narrow instruments, and contrast the strengths and complementarities of the two detection strategies. We update the science goals and associated instrumental performances that envisioned projects can include in their design in order to optimize discovery potential.
{"title":"Observational strategies for ultrahigh-energy neutrinos: the importance of deep sensitivity for detection and astronomy","authors":"Kumiko Kotera, Mainak Mukhopadhyay, Rafael Alves Batista, Derek Fox, Olivier Martineau-Huynh, Kohta Murase, Stephanie Wissel and Andrew Zeolla","doi":"10.1088/1475-7516/2026/01/027","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/027","url":null,"abstract":"Detecting ultrahigh-energy neutrinos can take two complementary approaches with different trade-offs. 1) Wide and shallow: aim for the largest effective volume, and to be cost-effective, go for wide field-of-view but at the cost of a shallow instantaneous sensitivity — this is less complex conceptually, and has strong discovery potential for serendipitous events. However, it is unclear if any source can be identified, following detection. And 2) Deep and narrow: here one uses astrophysical and multi-messenger information to target the most likely sources and populations that could emit neutrinos — these instruments have deep instantaneous sensitivity albeit a narrow field of view. Such an astrophysically-motivated approach provides higher chances for detection of known/observed source classes, and ensures multi-messenger astronomy. However, it has less potential for serendipitous discoveries. In light of the recent progress in multi-messenger and time-domain astronomy, we assess the power of the deep and narrow instruments, and contrast the strengths and complementarities of the two detection strategies. We update the science goals and associated instrumental performances that envisioned projects can include in their design in order to optimize discovery potential.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"16 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006165","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 : 2026-01-14DOI: 10.1088/1475-7516/2026/01/026
S.A. Paston and A.J. Ziyatdinov
We investigate the possibility of explaining the observed effects usually attributed to the existence of dark matter through a transition from GR to a modified theory of gravity — embedding gravity. Since this theory can be reformulated as GR with additional fictitious matter of embedding gravity (FMEG), which moves independently of ordinary matter, we analyse solutions in which FMEG behaves similarly to cold dark matter. An upper bound on the possible density of FMEG is obtained, which explains the absence of dark matter effects on small scales. Possible static condensed structures of FMEG are found, which can be reduced to configurations of the types wall, string, and sphere. In the latter case, FMEG exhibits the properties of an isothermal ideal gas which has a linear equation of state. The emerging spherical condensations of FMEG create potential wells that facilitate galaxy formation. For large values of the radius, the corresponding density distribution profile behaves in the same way as the pseudo-isothermal profile (ISO), which is successfully employed in fitting galactic dark halo regions, and provides flat galactic rotation curves.
{"title":"Possible types of dark matter condensation in embedding gravity","authors":"S.A. Paston and A.J. Ziyatdinov","doi":"10.1088/1475-7516/2026/01/026","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/026","url":null,"abstract":"We investigate the possibility of explaining the observed effects usually attributed to the existence of dark matter through a transition from GR to a modified theory of gravity — embedding gravity. Since this theory can be reformulated as GR with additional fictitious matter of embedding gravity (FMEG), which moves independently of ordinary matter, we analyse solutions in which FMEG behaves similarly to cold dark matter. An upper bound on the possible density of FMEG is obtained, which explains the absence of dark matter effects on small scales. Possible static condensed structures of FMEG are found, which can be reduced to configurations of the types wall, string, and sphere. In the latter case, FMEG exhibits the properties of an isothermal ideal gas which has a linear equation of state. The emerging spherical condensations of FMEG create potential wells that facilitate galaxy formation. For large values of the radius, the corresponding density distribution profile behaves in the same way as the pseudo-isothermal profile (ISO), which is successfully employed in fitting galactic dark halo regions, and provides flat galactic rotation curves.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"102 16 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962051","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 : 2026-01-12DOI: 10.1088/1475-7516/2026/01/024
Pasquale Di Bari and Xubin Hu
We discuss the impact of flavour coupling on the predictions of low energy neutrino parameters from SO(10)-inspired leptogenesis (SO10INLEP). The right-handed (RH) neutrino mass spectrum is strongly hierarchical so that successful leptogenesis relies on generating the asymmetry from next-to-lightest RH neutrino decays (N2-leptogenesis) and circumventing the lightest RH neutrino washout. These two conditions yield distinctive predictions such as a lower bound on the lightest neutrino mass m1 ≳ 1 meV. We first review the status of SO10INLEP, noticing how cosmological observations are now testing a particular neutrino mass window, m1 ≃ (10–30) meV, where only the first octant is allowed and a large range of values for the Dirac phase is excluded. Including flavour coupling, we find that the lower bound relaxes to m1 ≳ 0.65 meV. Moreover, new muon-dominated solutions appear slightly relaxing the upper bound on the atmospheric mixing angle. We also study the impact on strong thermal SO10INLEP (ST-SO10INLEP) scenario where, in addition to successful leptogenesis, one can washout a large pre-existing asymmetry. Contrarily to naive expectations, for which flavour coupling could jeopardise the scenario allowing a large pre-existing asymmetry to survive unconditionally, we show, and explain analytically, that ST-SO10INLEP is still viable within almost the same allowed region of parameters. There is even a slight relaxation of the m1 viable window from (9–30)meV to (4–40)meV for a 10-3 pre-existing asymmetry. The new results from atmospheric neutrinos, mildly favouring normal ordering and first octant, are now in nice agreement with the predictions of ST-SO10INLEP. Intriguingly, the predicted 0νββ signal is starting to be within the reach of KamLAND-Zen.
{"title":"Impact of flavour coupling on SO(10)-inspired leptogenesis","authors":"Pasquale Di Bari and Xubin Hu","doi":"10.1088/1475-7516/2026/01/024","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/024","url":null,"abstract":"We discuss the impact of flavour coupling on the predictions of low energy neutrino parameters from SO(10)-inspired leptogenesis (SO10INLEP). The right-handed (RH) neutrino mass spectrum is strongly hierarchical so that successful leptogenesis relies on generating the asymmetry from next-to-lightest RH neutrino decays (N2-leptogenesis) and circumventing the lightest RH neutrino washout. These two conditions yield distinctive predictions such as a lower bound on the lightest neutrino mass m1 ≳ 1 meV. We first review the status of SO10INLEP, noticing how cosmological observations are now testing a particular neutrino mass window, m1 ≃ (10–30) meV, where only the first octant is allowed and a large range of values for the Dirac phase is excluded. Including flavour coupling, we find that the lower bound relaxes to m1 ≳ 0.65 meV. Moreover, new muon-dominated solutions appear slightly relaxing the upper bound on the atmospheric mixing angle. We also study the impact on strong thermal SO10INLEP (ST-SO10INLEP) scenario where, in addition to successful leptogenesis, one can washout a large pre-existing asymmetry. Contrarily to naive expectations, for which flavour coupling could jeopardise the scenario allowing a large pre-existing asymmetry to survive unconditionally, we show, and explain analytically, that ST-SO10INLEP is still viable within almost the same allowed region of parameters. There is even a slight relaxation of the m1 viable window from (9–30)meV to (4–40)meV for a 10-3 pre-existing asymmetry. The new results from atmospheric neutrinos, mildly favouring normal ordering and first octant, are now in nice agreement with the predictions of ST-SO10INLEP. Intriguingly, the predicted 0νββ signal is starting to be within the reach of KamLAND-Zen.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"29 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145955144","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 : 2026-01-12DOI: 10.1088/1475-7516/2026/01/025
Kai Schmitz and Tobias Schröder
Cosmic strings represent an attractive source of gravitational waves (GWs) from the early Universe. However, numerical computation of the GW signal from cosmic strings requires the evaluation of complicated integral and sum expressions, which can become computationally costly in large parameter scans. This motivates us to rederive the GW signal from a network of local stable cosmic strings in the Nambu-Goto approximation and based on the velocity-dependent one-scale model from a “pedestrian” perspective. That is, we derive purely analytical expressions for the total GW spectrum, which remain exact wherever possible and whose error can be tracked and reduced in a controlled way in crucial situations in which we are forced to introduce approximations. In this way, we obtain powerful formulas that, unlike existing results in the literature, are valid across the entire frequency spectrum and across the entire conceivable range of cosmic-string tensions. We provide an in-depth discussion of the GW spectra thus obtained, including their characteristic break frequencies and approximate power-law behaviors, comment on the effect of changes in the effective number of degrees of freedom during radiation domination, and conclude with a concise summary of our main formulas that can readily be used in future studies.
{"title":"Gravitational waves from cosmic strings for pedestrians","authors":"Kai Schmitz and Tobias Schröder","doi":"10.1088/1475-7516/2026/01/025","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/025","url":null,"abstract":"Cosmic strings represent an attractive source of gravitational waves (GWs) from the early Universe. However, numerical computation of the GW signal from cosmic strings requires the evaluation of complicated integral and sum expressions, which can become computationally costly in large parameter scans. This motivates us to rederive the GW signal from a network of local stable cosmic strings in the Nambu-Goto approximation and based on the velocity-dependent one-scale model from a “pedestrian” perspective. That is, we derive purely analytical expressions for the total GW spectrum, which remain exact wherever possible and whose error can be tracked and reduced in a controlled way in crucial situations in which we are forced to introduce approximations. In this way, we obtain powerful formulas that, unlike existing results in the literature, are valid across the entire frequency spectrum and across the entire conceivable range of cosmic-string tensions. We provide an in-depth discussion of the GW spectra thus obtained, including their characteristic break frequencies and approximate power-law behaviors, comment on the effect of changes in the effective number of degrees of freedom during radiation domination, and conclude with a concise summary of our main formulas that can readily be used in future studies.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"29 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145955143","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 : 2026-01-08DOI: 10.1088/1475-7516/2026/01/022
Felicitas Keil, Savvas Nesseris, Isaac Tutusaus and Alain Blanchard
The distance duality relation (DDR) relates two independent ways of measuring cosmological distances, namely the angular diameter distance and the luminosity distance. These can be measured with baryon acoustic oscillations (BAO) and Type Ia supernovae (SNe Ia), respectively. Here, we use recent DESI DR1, Pantheon+, SH0ES and DES-SN5YR data to test this fundamental relation. We employ a parametrised approach and also use model-independent Generic Algorithms (GA), which are a machine learning method where functions evolve loosely based on biological evolution. When we use DESI and Pantheon+ data without Cepheid calibration or big bang nucleosynthesis (BBN), there is a 2σ discrepancy with the DDR in the parametrised approach. Then, we add high-redshift BBN data and the low-redshift SH0ES Cepheid calibration. This reflects the Hubble tension since both data sets are in tension in the standard cosmological model ΛCDM. In this case, we find a significant violation of the DDR in the parametrised case at 6σ. Replacing the Pantheon+ SNe Ia data by DES-SN5YR, we find similar results. For the model-independent approach, we find no deviation in the uncalibrated case and a small deviation with BBN and Cepheids which remains at 1σ. This shows the importance of considering model-independent approaches for the DDR.
{"title":"Probing the distance duality relation with machine learning and recent data","authors":"Felicitas Keil, Savvas Nesseris, Isaac Tutusaus and Alain Blanchard","doi":"10.1088/1475-7516/2026/01/022","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/022","url":null,"abstract":"The distance duality relation (DDR) relates two independent ways of measuring cosmological distances, namely the angular diameter distance and the luminosity distance. These can be measured with baryon acoustic oscillations (BAO) and Type Ia supernovae (SNe Ia), respectively. Here, we use recent DESI DR1, Pantheon+, SH0ES and DES-SN5YR data to test this fundamental relation. We employ a parametrised approach and also use model-independent Generic Algorithms (GA), which are a machine learning method where functions evolve loosely based on biological evolution. When we use DESI and Pantheon+ data without Cepheid calibration or big bang nucleosynthesis (BBN), there is a 2σ discrepancy with the DDR in the parametrised approach. Then, we add high-redshift BBN data and the low-redshift SH0ES Cepheid calibration. This reflects the Hubble tension since both data sets are in tension in the standard cosmological model ΛCDM. In this case, we find a significant violation of the DDR in the parametrised case at 6σ. Replacing the Pantheon+ SNe Ia data by DES-SN5YR, we find similar results. For the model-independent approach, we find no deviation in the uncalibrated case and a small deviation with BBN and Cepheids which remains at 1σ. This shows the importance of considering model-independent approaches for the DDR.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"45 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145920145","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 : 2026-01-08DOI: 10.1088/1475-7516/2026/01/023
James Adam, Roy Maartens, Julien Larena, Chris Clarkson and Ruth Durrer
The standard cosmological model assumes the Cosmological Principle. However, recent observations hint at possible violations of isotropy on large scales, possibly through late-time anisotropic expansion. Here we investigate the potential of cross-correlations between CMB lensing convergence κ and galaxy cosmic shear B-modes as a novel probe of such late-time anisotropies. Our signal-to-noise forecasts reveal that information from the κ-B cross-correlation is primarily contained on large angular scales (ℓ≲200). We find that this cross-correlation for a Euclid-like galaxy survey is sensitive to anisotropy at the percent level. Making use of tomography yields a modest improvement of ∼ 20% in detection power. Incorporating the galaxy E-B cross-correlations would further enhance these constraints.
{"title":"Probing the Cosmological Principle with CMB lensing and cosmic shear","authors":"James Adam, Roy Maartens, Julien Larena, Chris Clarkson and Ruth Durrer","doi":"10.1088/1475-7516/2026/01/023","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/023","url":null,"abstract":"The standard cosmological model assumes the Cosmological Principle. However, recent observations hint at possible violations of isotropy on large scales, possibly through late-time anisotropic expansion. Here we investigate the potential of cross-correlations between CMB lensing convergence κ and galaxy cosmic shear B-modes as a novel probe of such late-time anisotropies. Our signal-to-noise forecasts reveal that information from the κ-B cross-correlation is primarily contained on large angular scales (ℓ≲200). We find that this cross-correlation for a Euclid-like galaxy survey is sensitive to anisotropy at the percent level. Making use of tomography yields a modest improvement of ∼ 20% in detection power. Incorporating the galaxy E-B cross-correlations would further enhance these constraints.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"19 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145920528","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 : 2026-01-07DOI: 10.1088/1475-7516/2026/01/020
Hyeonmo Koo and Jae-Weon Lee
We investigate the impact of repulsive self-interaction in ultralight dark matter (ULDM) on dynamical friction in circular orbits in ULDM halos and its implications for the Fornax dwarf spheroidal (dSph) galaxy's globular clusters. Using the Gross-Pitaevskii-Poisson equations, we derive the dynamical friction force considering soliton density profiles for both non-interacting and strongly self-interacting ULDM. Our results show that self-interactions reduce the dynamical friction effect further than both the non-interacting ULDM and standard cold dark matter models. Furthermore, we derive the low Mach number approximation to simplify the analysis in the subsonic motion, where the tangential component of dynamical friction dominates. Applying these findings to the Fornax dSph, we calculate the infall timescales of globular clusters, demonstrating that strong self-interaction can address the timing problem more effectively. We constrain the parameter space for ULDM particle mass and self-coupling constant, which are consistent with other constraints from astronomical and cosmological observations.
{"title":"Dynamical friction for circular orbits in self-interacting ultralight dark matter and Fornax globular clusters","authors":"Hyeonmo Koo and Jae-Weon Lee","doi":"10.1088/1475-7516/2026/01/020","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/020","url":null,"abstract":"We investigate the impact of repulsive self-interaction in ultralight dark matter (ULDM) on dynamical friction in circular orbits in ULDM halos and its implications for the Fornax dwarf spheroidal (dSph) galaxy's globular clusters. Using the Gross-Pitaevskii-Poisson equations, we derive the dynamical friction force considering soliton density profiles for both non-interacting and strongly self-interacting ULDM. Our results show that self-interactions reduce the dynamical friction effect further than both the non-interacting ULDM and standard cold dark matter models. Furthermore, we derive the low Mach number approximation to simplify the analysis in the subsonic motion, where the tangential component of dynamical friction dominates. Applying these findings to the Fornax dSph, we calculate the infall timescales of globular clusters, demonstrating that strong self-interaction can address the timing problem more effectively. We constrain the parameter space for ULDM particle mass and self-coupling constant, which are consistent with other constraints from astronomical and cosmological observations.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"41 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145908352","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 : 2026-01-07DOI: 10.1088/1475-7516/2026/01/021
Eleanor Stuart and Kris Pardo
Dark matter (DM) models with a non-zero DM-baryon interaction cross section imply energy transfer between DM and baryons. We present a new method of constraining the DM-baryon interaction cross section and DM particle mass for velocity-independent interactions using the thermodynamics of galaxy clusters. If the baryonic gas in these clusters is in thermodynamic equilibrium and DM cools baryons, this cooling rate is limited by the net heating rate of other mechanisms in the cluster. We use the REFLEX clusters from the Meta-Catalogue of X-ray detected Clusters of Galaxies (MCXC) with mass estimates from the Atacama Cosmology Telescope (ACT) catalog of Sunyaev-Zel'dovich (SZ) selected galaxy clusters. This yields 95% upper bounds on the DM-proton interaction cross section for velocity-independent interactions of σ0 ≤ 9.3 × 10-28 cm2 for DM masses, mχ = 10-4–10-1 GeV. These constraints are within an order of magnitude of the best constraints derived in this mass range, and serve as a complementary, independent constraint. We also apply this model to the fractional interacting DM scenario, where only 10% and 1% of the DM is interacting. Unlike other methods, this constraint scales linearly with this fraction. This yields 95% upper bounds of σ0 ≤ 1.1 × 10-26 cm2 and σ0 ≤ 8.2 × 10-26 cm2, which are the strongest existing constraints for this scenario. This paper serves as a proof of concept. Upcoming SZ measurements will provide temperature profiles for galaxy clusters. Combining these measurements with more complex thermodynamic models could lead to more robust constraints.
{"title":"Constraints on the dark matter-baryon interaction cross section from galaxy cluster thermodynamics","authors":"Eleanor Stuart and Kris Pardo","doi":"10.1088/1475-7516/2026/01/021","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/01/021","url":null,"abstract":"Dark matter (DM) models with a non-zero DM-baryon interaction cross section imply energy transfer between DM and baryons. We present a new method of constraining the DM-baryon interaction cross section and DM particle mass for velocity-independent interactions using the thermodynamics of galaxy clusters. If the baryonic gas in these clusters is in thermodynamic equilibrium and DM cools baryons, this cooling rate is limited by the net heating rate of other mechanisms in the cluster. We use the REFLEX clusters from the Meta-Catalogue of X-ray detected Clusters of Galaxies (MCXC) with mass estimates from the Atacama Cosmology Telescope (ACT) catalog of Sunyaev-Zel'dovich (SZ) selected galaxy clusters. This yields 95% upper bounds on the DM-proton interaction cross section for velocity-independent interactions of σ0 ≤ 9.3 × 10-28 cm2 for DM masses, mχ = 10-4–10-1 GeV. These constraints are within an order of magnitude of the best constraints derived in this mass range, and serve as a complementary, independent constraint. We also apply this model to the fractional interacting DM scenario, where only 10% and 1% of the DM is interacting. Unlike other methods, this constraint scales linearly with this fraction. This yields 95% upper bounds of σ0 ≤ 1.1 × 10-26 cm2 and σ0 ≤ 8.2 × 10-26 cm2, which are the strongest existing constraints for this scenario. This paper serves as a proof of concept. Upcoming SZ measurements will provide temperature profiles for galaxy clusters. Combining these measurements with more complex thermodynamic models could lead to more robust constraints.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"70 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145908353","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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