Journal of Cosmology and Astroparticle Physics最新文献

{"title":"Hybrid summary statistics: neural weak lensing inference beyond the power spectrum","authors":"T. Lucas Makinen, Alan Heavens, Natalia Porqueres, Tom Charnock, Axel Lapel and Benjamin D. Wandelt","doi":"10.1088/1475-7516/2025/01/095","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/095","url":null,"abstract":"Cosmological inference relies on compressed forms of the raw data for analysis, with traditional methods exploiting physics knowledge to define summary statistics, such as power spectra, that are known to capture much of the information. An alternative approach is to ask a neural network to find a set of informative summary statistics from data, which can then be analysed either by likelihood- or simulation-based inference. This has the advantage that for non-Gaussian fields, they may capture more information than two-point statistics. However, a disadvantage is that the network almost certainly relearns that two-point statistics are informative. In this paper, we introduce a new hybrid method, which combines the best of both: we use our domain knowledge to define informative physics-based summary statistics, and explicitly ask the network to augment the set with extra statistics that capture information that is not already in the existing summaries. This yields a new, general loss formalism that reduces both the number of simulations and network size needed to extract useful non-Gaussian information from cosmological fields, and guarantees that the resulting summary statistics are at least as informative as the power spectrum. In combination, they can then act as powerful inputs to implicit inference of model parameters. We use a generalisation of Information Maximising Neural Networks (IMNNs) to obtain the extra summaries, and obtain parameter constraints from simulated tomographic weak gravitational lensing convergence maps. We study several dark matter simulation resolutions in low- and high-noise regimes. We show that i) the information-update formalism extracts at least 3× and up to 8× as much information as the angular power spectrum in all noise regimes, ii) the network summaries are highly complementary to existing 2-point summaries, and iii) our formalism allows for networks with extremely lightweight architectures to match much larger regression networks with far fewer simulations needed to obtain asymptotically optimal inference.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"24 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Schwarzschild lensing from geodesic deviation","authors":"Zhao Li, Xiao Guo, Tan Liu, Tao Zhu and Wen Zhao","doi":"10.1088/1475-7516/2025/01/092","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/092","url":null,"abstract":"We revisit the gravitational lensing of light or gravitational waves by a Schwarzschild black hole in geometric optics. Rather than focusing on a single massless particle, we investigate the collective behavior of a congruence of light or gravitational rays, described by the geodesic deviation equation (GDE). By projecting GDE onto the Newman-Penrose tetrad, we decouple the equation and find an analytical Dyson-like series solution in the weak deflection and thin lens limits. Using this solution, we analyze the evolution of the cross-sectional area and axis ratio. Finally, we reproduce the magnification and axis ratio of the lensing images up to second-order weak deflection approximation, addressing some previously overlooked corrections.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"11 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A model for the redshift-space galaxy 4-point correlation function","authors":"William Ortolá Leonard, Zachary Slepian and Jiamin Hou","doi":"10.1088/1475-7516/2025/01/090","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/090","url":null,"abstract":"The field of cosmology is entering an epoch of unparalleled wealth of observational data thanks to galaxy surveys such as DESI, Euclid, and Roman. Therefore, it is essential to have a firm theoretical basis that allows the effective analysis of the data. With this purpose, we compute the nonlinear, gravitationally-induced connected galaxy 4-point correlation function (4PCF) at the tree level in Standard Perturbation Theory (SPT), including redshift-space distortions (RSD). We begin from the trispectrum and take its inverse Fourier transform into configuration space, exploiting the isotropic basis functions of [1]. We ultimately reduce the configuration-space expression to low-dimensional radial integrals of the power spectrum. This model will enable the use of the BAO feature in the connected 4PCF to sharpen our constraints on the expansion history of the Universe. It will also offer an additional avenue for determining the galaxy bias parameters, and thus tighten our cosmological constraints by breaking degeneracies. Survey geometry can be corrected in the 4PCF, and many systematics are localized, which is an advantage over data analysis with the trispectrum.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"15 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravitational waveforms from periodic orbits around a quantum-corrected black hole","authors":"Sen Yang, Yu-Peng Zhang, Tao Zhu, Li Zhao and Yu-Xiao Liu","doi":"10.1088/1475-7516/2025/01/091","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/091","url":null,"abstract":"Extreme mass-ratio inspirals are crucial sources for future space-based gravitational wave detections. Gravitational waveforms emitted by extreme mass-ratio inspirals are closely related to the orbital dynamics of small celestial objects, which vary with the underlying spacetime geometry. Despite the tremendous success of general relativity, there are unsolved issues such as singularities in both black holes and cosmology. Loop quantum gravity, a theory addressing these singularity problems, offers a framework for regular black holes. In this paper, we focus on periodic orbits of a small celestial object around a supermassive quantum-corrected black hole in loop quantum gravity and compute the corresponding gravitational waveforms. We view the small celestial object as a massive test particle and obtain its four-velocity and effective potential. We explore the effects of quantum corrections on marginally bound orbits, innermost stable circular orbits, and other periodic orbits. Using the numerical kludge scheme, we further explore the gravitational waveforms of the small celestial object along different periodic orbits. The waveforms exhibit distinct zoom and whirl phases in a complete orbital period, closely tied to the quantum parameter α̂. We also perform a spectral analysis of the gravitational waves from these periodic orbits and assess their detectability. With the steady progress of space-based gravitational wave detection programs, our findings will contribute to utilizing extreme mass-ratio inspirals to test and understand the properties of quantum-corrected black holes.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"74 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation of common envelope stage in close binary systems: comparison between Newtonian and modified gravity","authors":"A.V. Astashenok, A.S. Baigashov, A.S. Tepliakov, K.P. Gusev and E.R. Shamardina","doi":"10.1088/1475-7516/2025/01/093","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/093","url":null,"abstract":"We consider the important stage in evolution of close binary system namely common envelope phase in framework of various models of modified gravity. The comparison of results between calculations in Newtonian gravity and modified gravity allows to estimate possible observational imprints of modified gravity. Although declination from Newtonian gravity should be negligible we can propose that due to the long times some new effects can appear. We use the moving-mesh code AREPO for numerical simulation of binary system consisting of ∼ M⊙ white dwarf and a red giant with mass ∼ 2M⊙. For implementing modified gravity into AREPO code we apply the method of (pseudo)potential, assuming that modified gravity can be described by small corrections to usual Newtonian gravitational potential. As in Newtonian case initial orbit has to shrink due to the energy transfer to the envelope of a giant. We investigated evolution of common envelope in a case of simple model of modified gravity with various values of parameters and compared results with simulation in frames of Newtonian gravity.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"18 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bridging dark energy and black holes with EFT: frame transformation and gravitational wave speed","authors":"Shinji Mukohyama, Emeric Seraille, Kazufumi Takahashi and Vicharit Yingcharoenrat","doi":"10.1088/1475-7516/2025/01/085","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/085","url":null,"abstract":"Typically, constraints on parameters of the effective field theory (EFT) of dark energy have been obtained in the Jordan frame, where matter fields are minimally coupled to gravity. To connect these constraints with those of the EFT of black hole perturbations with a timelike scalar profile, it is necessary to perform a frame transformation on the EFT in general. In this paper, we study the conformal/disformal transformation of EFT parameters on an arbitrary background. Furthermore, we explore the effect of an EFT operator M6(r) σ̅μνδKναδKαμ, which is elusive to the LIGO/Virgo bound on gravitational-wave speed, on the dynamics of odd-parity black hole perturbations. Intriguingly, a deviation from luminal propagation shows up only in the vicinity of the black hole, and the speeds of perturbations in the radial and angular directions are different in general due to the traceless part σ̅μν of the background extrinsic curvature. This study establishes an important link between cosmological constraints and those obtained in the black hole regime.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"46 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravitino thermal production, dark matter, and reheating of the Universe","authors":"Helmut Eberl, Ioannis D. Gialamas and Vassilis C. Spanos","doi":"10.1088/1475-7516/2025/01/079","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/079","url":null,"abstract":"We present a full one-loop calculation of the gravitino thermal production rate, beyond the so-called hard thermal loop approximation, using the corresponding thermal spectral functions in numerical form on both sides of the light cone. This framework requires a full numerical evaluation. We interpret our results within the framework of a general supergravity-based model, remaining agnostic about the specifics of supersymmetry breaking. In this context, assuming that gravitinos constitute the entirety of the dark matter in the Universe imposes strict constraints on the reheating temperature. For example, with a gluino mass at the current LHC limit, a maximum reheating temperature of Treh ≃ 109 GeV is compatible with a gravitino mass of m3/2 ≃ 1 TeV. Additionally, with a reheating temperature an order of magnitude lower at Treh ≃ 108 GeV, the common gaugino mass M1/2 can range from 2 to 4 TeV within the same gravitino mass range. For much higher values of M1/2, which are favored by current accelerator and cosmological data in the context of supersymmetric models, such as M1/2 = 10 TeV, and for m3/2 ≃ 1 TeV the reheating temperature compatible with the gravitino dark matter scenario is 107 GeV. If other dark matter particles are considered, the reheating temperature could be much lower.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"33 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exact results on the number of gravitons radiated during binary inspiral","authors":"Youngjoo Chung and Hyun Seok Yang","doi":"10.1088/1475-7516/2025/01/078","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/078","url":null,"abstract":"We derive an exact formula F(e) which provides a concrete estimate for the total number and angular momentum of gravitons emitted during the nonrelativistic inspiral of two black holes. We show that the function F(e) is a slowly growing monotonic function of the eccentricity 0 ≤ e ≤ 1 and F(1) = 1.0128 ⋯. We confirm and extend the results obtained by Page for the function F(e). We also get an exact result for the ratio ν (ei) = 2ħN(Li, ei)/Li where the numerator 2ħN(Li, ei) is the sum of the spin angular momentum magnitudes of the gravitons emitted and N(Li, ei) is the total number of gravitons emitted in the gravitational waves during nonrelativistic inspiral from an initial eccentricity ei down to a final eccentricity e = 0 and the denominator Li is the magnitude of the initial orbital angular momentum. If the orbit starts off with unit eccentricity ei = 1, we get the value ν(1) = 1.002 268 666 2 ± 10-10 which confirms the Page's conjecture that the true value of ν(1) will lie between 1.001⋯ and 1.003⋯. We also show that the formula F(e) for gravitons emitted, originally expressed as an infinite series, can be represented by a single function through an integral representation.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"95 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Everything hot everywhere all at once: neutrinos and hot dark matter as a single effective species","authors":"Amol Upadhye, Markus R. Mosbech, Giovanni Pierobon and Yvonne Y.Y. Wong","doi":"10.1088/1475-7516/2025/01/077","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/077","url":null,"abstract":"Observational cosmology is rapidly closing in on a measurement of the sum Mν of neutrino masses, at least in the simplest cosmologies, while opening the door to probes of non-standard hot dark matter (HDM) models. By extending the method of effective distributions, we show that any collection of HDM species, with arbitrary masses, temperatures, and distribution functions, including massive neutrinos, may be represented as a single effective HDM species. Implementing this method in the FlowsForTheMasses non-linear perturbation theory for free-streaming particles, we study non-standard HDM models that contain thermal QCD axions or generic bosons in addition to standard neutrinos, as well as non-standard neutrino models wherein either the distribution function of the neutrinos or their temperature is changed. Along the way, we substantially improve the accuracy of this perturbation theory at low masses, bringing it into agreement with the high-resolution TianNu neutrino N-body simulation to ≈ 2% at k = 0.1 h/Mpc and to ≤ 21% over the range k ≤ 1 h/Mpc. We accurately reproduce the results of simulations including axions and neutrinos of multiple masses. Studying the differences between the normal, inverted, and degenerate neutrino mass orderings on their non-linear power, we quantify the error in the common approximation of degenerate masses. We release our code publicly at http://github.com/upadhye/FlowsForTheMassesII.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"30 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravitational waves induced by scalar perturbations with a broken power-law peak","authors":"Chong-Zhi Li, Chen Yuan and Qing-Guo Huang","doi":"10.1088/1475-7516/2025/01/067","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/01/067","url":null,"abstract":"We give an analytical approximation for the energy spectrum of the scalar-induced gravitational waves (SIGWs) generated by a broken power-law power spectrum, and find that both the asymptotic power-law tails and the intermediate peak contribute distinct features to the SIGW spectrum. Moreover, the broken power-law power spectrum has abundant near-peak features and our results can be used as a near-peak approximation that covers a wide range of models. Our analytical approximation is useful in the rapid generation of the SIGW energy spectrum, which is beneficial for gravitational wave data analysis.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"20 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986127","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}