Journal of Cosmology and Astroparticle Physics最新文献

{"title":"Efficient Massive Black Hole Binary parameter estimation for LISA using Sequential Neural Likelihood","authors":"Iván Martín Vílchez and Carlos F. Sopuerta","doi":"10.1088/1475-7516/2025/04/022","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/022","url":null,"abstract":"The inspiral, merger, and ringdown of Massive Black Hole Binaries (MBHBs) is one the main sources of Gravitational Waves (GWs) for the future Laser Interferometer Space Antenna (LISA), an ESA-led mission in the implementation phase. It is expected that LISA will detect these systems throughout the entire observable universe. Robust and efficient data analysis algorithms are necessary to detect and estimate physical parameters for these systems. In this work, we explore the application of Sequential Neural Likelihood, a simulation-based inference algorithm, to detect and characterize MBHB GW signals in synthetic LISA data. We describe in detail the different elements of the method, their performance and possible alternatives that can be used to enhance the performance. Instead of sampling from the conventional likelihood function, which requires a forward simulation for each evaluation, this method constructs a surrogate likelihood that is ultimately described by a neural network trained from a dataset of simulations of the MBHB signals and noise. One important advantage of this method is that, given that the likelihood is independent of the priors, we can iteratively train models that target specific observations in a fraction of the time and computational cost that other traditional and machine learning-based strategies would require. Because of the iterative nature of the method, we are able to train models to obtain qualitatively similar posteriors with less than 2% of the simulator calls that Markov Chain Monte Carlo methods would require. We compare these posteriors with those obtained from Markov Chain Monte Carlo techniques and discuss the differences that appear, in particular in relation with the important role that data compression has in the modular implementation of the method that we present. We also discuss different strategies to improve the performance of the algorithms.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"23 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143805893","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":"DESI 2024 III: baryon acoustic oscillations from galaxies and quasars","authors":"A.G. Adame, J. Aguilar, S. Ahlen, S. Alam, D.M. Alexander, M. Alvarez, O. Alves, A. Anand, U. Andrade, E. Armengaud, S. Avila, A. Aviles, H. Awan, S. Bailey, C. Baltay, A. Bault, J. Behera, S. BenZvi, F. Beutler, D. Bianchi, C. Blake, R. Blum, S. Brieden, A. Brodzeller, D. Brooks, E. Buckley-Geer, E. Burtin, R. Calderon, R. Canning, A. Carnero Rosell, R. Cereskaite, J.L. Cervantes-Cota, S. Chabanier, E. Chaussidon, J. Chaves-Montero, S. Chen, X. Chen, T. Claybaugh, S. Cole, A. Cuceu, T.M. Davis, K. Dawson, A. de la Macorra, A. de Mattia, N. Deiosso, A. Dey, B. Dey, Z. Ding, P. Doel, J. Edelstein, S. Eftekharzadeh, D.J. Eisenstein, A. Elliott, P. Fagrelius, K. Fanning, S. Ferraro, J. Ereza, N. Findlay, B. Flaugher, A. Font-Ribera, D. Forero-Sánchez, J.E. Forero-Romero, C. Garcia-Quintero, E. Gaztañaga, H. Gil-Marín, S.Gontcho A. Gontcho, A.X. Gonzalez-Morales, V. Gonzalez-Perez, C. Gordon, D. Green, D. Gruen, R. Gsponer, G. Gutierrez, J. Guy, B. Hadzhiyska, C. Hahn, M.M.S. Han..","doi":"10.1088/1475-7516/2025/04/012","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/012","url":null,"abstract":"We present the DESI 2024 galaxy and quasar baryon acoustic oscillations (BAO) measurements using over 5.7 million unique galaxy and quasar redshifts in the range 0.1 < z < 2.1. Divided by tracer type, we utilize 300,017 galaxies from the magnitude-limited Bright Galaxy Survey with 0.1 < z < 0.4, 2,138,600 Luminous Red Galaxies with 0.4 < z < 1.1, 2,432,022 Emission Line Galaxies with 0.8 < z < 1.6, and 856,652 quasars with 0.8 < z < 2.1, over a ∼ 7,500 square degree footprint. The analysis was blinded at the catalog-level to avoid confirmation bias. All fiducial choices of the BAO fitting and reconstruction methodology, as well as the size of the systematic errors, were determined on the basis of the tests with mock catalogs and the blinded data catalogs. We present several improvements to the BAO analysis pipeline, including enhancing the BAO fitting and reconstruction methods in a more physically-motivated direction, and also present results using combinations of tracers. We employ a unified BAO analysis method across all tracers. We present a re-analysis of SDSS BOSS and eBOSS results applying the improved DESI methodology and find scatter consistent with the level of the quoted SDSS theoretical systematic uncertainties. With the total effective survey volume of ∼ 18 Gpc3, the combined precision of the BAO measurements across the six different redshift bins is ∼0.52%, marking a 1.2-fold improvement over the previous state-of-the-art results using only first-year data. We detect the BAO in all of these six redshift bins. The highest significance of BAO detection is 9.1σ at the effective redshift of 0.93, with a constraint of 0.86% placed on the BAO scale. We find that our observed BAO scales are systematically larger than the prediction of thePlanck 2018-ΛCDM at z < 0.8. We translate the results into transverse comoving distance and radial Hubble distance measurements, which are used to constrain cosmological models in our companion paper.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"35 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143790183","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":"Exploring Faraday rotation signatures and population bounds for primordial magnetic black holes","authors":"Arka Banerjee, Lalit Singh Bhandari, Ashwat Jain and Arun M. Thalapillil","doi":"10.1088/1475-7516/2025/04/011","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/011","url":null,"abstract":"Primordial black holes bearing magnetic charges may bypass the constraints imposed by Hawking radiation, thereby enabling reasonable present-day populations, even for masses below 1015 g — a range previously considered improbable. They could, therefore, conceivably contribute to a component of dark matter. We investigate novel Faraday rotation signatures exhibited by primordial magnetic black holes while also establishing new Parker-type bounds on their populations. For the latter, we bound the dark matter fraction from intergalactic magnetic fields in cosmic voids (fDM ≲ 10-8) and cosmic web filaments (fDM ≲ 10-4), notably eclipsing previous bounds. Exploring Faraday rotation effects, we discern a pronounced rotation of the polarization angle and the rotation measure values for extremal primordial magnetic black holes with masses Mex.BH ≳ 10-6 M⊙. This makes them potentially detectable in current observations. A comparative investigation finds that the effects are notably greater than for a neutron star, like a Magnetar, with a similar magnetic field at the surface. Moreover, the polarization angle maps for primordial magnetic black holes exhibit unique features, notably absent in other astrophysical magnetic configurations. In this context, we also introduce a simple integral measure, offering a quantitative measure for their discrimination in many scenarios. These traits potentially suggest a robust avenue for their observational detection and differentiation.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"12 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766443","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 from metastable cosmic strings in supersymmetric new inflation model","authors":"Akifumi Chitose, Masahiro Ibe, Shunsuke Neda and Satoshi Shirai","doi":"10.1088/1475-7516/2025/04/010","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/010","url":null,"abstract":"Recent observations by pulsar timing arrays (PTAs) indicate a potential detection of a stochastic gravitational wave (GW) background. Metastable cosmic strings have been recognized as a possible source of the observed signals. In this paper, we propose an R-invariant supersymmetric new inflation model. It is characterized by a two-step symmetry breaking SU(2) → U(1)G → nothing, incorporating metastable cosmic strings. The field responsible for the initial symmetry breaking acts as the inflaton, while the second symmetry breaking occurs post-inflation, ensuring the formation of the cosmic string network without monopole production. Our model predicts symmetry breaking scales consistent with the string tensions favored by PTA data, GNμstr ∼ 10-5, where GN is the Newton constant. Notably, a low reheating temperature is required to suppress non-thermal gravitino production from the decay of inflaton sector fields. This also helps evading LIGO-Virgo-KAGRA constraints, while yielding a distinctive GW signature that future PTA and interferometer experiments can detect. Additionally, we examine the consistency of this scenario with non-thermal leptogenesis and supersymmetric dark matter.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"16 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766442","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":"Steepest growth in the primordial power spectrum from excited states at a sudden transition","authors":"Mattia Cielo, Gianpiero Mangano, Ofelia Pisanti and David Wands","doi":"10.1088/1475-7516/2025/04/007","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/007","url":null,"abstract":"Sudden phase transitions during inflation can give rise to strongly enhanced primordial density perturbations on scales much smaller than those directly probed by cosmic microwave background anisotropies. In this paper, we study the effect of the incoming quantum state on the steepest growth found in the primordial power spectrum using a simple model of an instantaneous transition during single-field inflation. We consider the case of a general de Sitter-invariant initial state for the inflaton field (the α-vacuum), and also an incoming state perturbed by a preceding transition. For the α-vacua we find that k6 growth is possible for α > 0, while k4 growth is seen for α ≤ 0, including the standard case of an initial Bunch-Davies vacuum state. The features of an enhanced primordial power spectrum on small scales are thus sensitive to the initial quantum state during inflation. We calculate the scalar-induced gravitational wave power spectrum for each case.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766440","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 robust cosmic standard ruler from the cross-correlations of galaxies and dark sirens","authors":"João Ferri, Ian L. Tashiro, L.R. Abramo, Isabela Matos, Miguel Quartin and Riccardo Sturani","doi":"10.1088/1475-7516/2025/04/008","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/008","url":null,"abstract":"Observations of gravitational waves (GWs) from dark sirens allow us to infer their locations and distances. Galaxies, on the other hand, have precise angular positions but no direct measurement of their distances — only redshifts. The cross-correlation of GWs, which we limit here to binary black hole mergers (BBH), in spherical shells of luminosity distance DL, with galaxies in shells of redshift z, leads to a direct measurement of the Hubble diagram DL(z). Since this standard ruler relies only on the statistical proximity of the dark sirens and galaxies (a general property of large-scale structures), it is essentially model-independent: the correlation is maximal when both redshift and DL shells coincide. We forecast the constraining power of this technique, which we call Peak Sirens, for run 5 (O5) of LIGO-Virgo-KAGRA (LVK), as well as for the third-generation observatories Einstein Telescope and Cosmic Explorer. We employ thousands of full-sky light cone simulations with realistic numbers for the tracers, and include masking by the Milky Way, lensing and inhomogeneous GW sky coverage. We find that the method is not expected to suffer from some of the issues present in other dark siren methods, such as biased constraints due to incompleteness of galaxy catalogs or dependence on priors for the merger rates of BBH. We show that with Peak Sirens, given the projected O5 sensitivity, LVK can measure H0 with 7% precision by itself, assuming ΛCDM, and 4% precision using external datasets to constrain Ωm. We also show that future third-generation GW detectors can achieve, without external data, sub-percent uncertainties in H0 assuming ΛCDM, and 3% in a more flexible w0waCDM model. The method also shows remarkable robustness against systematic effects such as the modeling of non-linear structure formation.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"31 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766907","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":"Multimuons in cosmic-ray events as seen in ALICE at the LHC","authors":"S. Acharya, A. Agarwal, G. Aglieri Rinella, L. Aglietta, M. Agnello, N. Agrawal, Z. Ahammed, S. Ahmad, S.U. Ahn, I. Ahuja, A. Akindinov, V. Akishina, M. Al-Turany, D. Aleksandrov, B. Alessandro, H.M. Alfanda, R. Alfaro Molina, B. Ali, A. Alici, N. Alizadehvandchali, A. Alkin, J. Alme, G. Alocco, T. Alt, A.R. Altamura, I. Altsybeev, J.R. Alvarado, C.O.R. Alvarez, M.N. Anaam, C. Andrei, N. Andreou, A. Andronic, E. Andronov, V. Anguelov, F. Antinori, P. Antonioli, N. Apadula, L. Aphecetche, H. Appelshäuser, C. Arata, S. Arcelli, R. Arnaldi, J.G.M.C.A. Arneiro, I.C. Arsene, M. Arslandok, A. Augustinus, R. Averbeck, D. Averyanov, M.D. Azmi, H. Baba, A. Badalà, J. Bae, Y. Bae, Y.W. Baek, X. Bai, R. Bailhache, Y. Bailung, R. Bala, A. Balbino, A. Baldisseri, B. Balis, Z. Banoo, V. Barbasova, F. Barile, L. Barioglio, M. Barlou, B. Barman, G.G. Barnaföldi, L.S. Barnby, E. Barreau, V. Barret, L. Barreto, C. Bartels, K. Barth, E. Bartsch, N. Bastid, S. Basu, G. Batigne, D. Battistini, B...","doi":"10.1088/1475-7516/2025/04/009","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/009","url":null,"abstract":"ALICE is a large experiment at the CERN Large Hadron Collider. Located 52 meters underground, its detectors are suitable to measure muons produced by cosmic-ray interactions in the atmosphere. In this paper, the studies of the cosmic muons registered by ALICE during Run 2 (2015–2018) are described. The analysis is limited to multimuon events defined as events with more than four detected muons (Nμ > 4) and in the zenith angle range 0° < θ < 50°. The results are compared with Monte Carlo simulations using three of the main hadronic interaction models describing the air shower development in the atmosphere: QGSJET-II-04, EPOS-LHC, and SIBYLL 2.3d. The interval of the primary cosmic-ray energy involved in the measured muon multiplicity distribution is about 4 × 1015 < Eprim < 6 × 1016 eV. In this interval none of the three models is able to describe precisely the trend of the composition of cosmic rays as the energy increases. However, QGSJET-II-04 is found to be the only model capable of reproducing reasonably well the muon multiplicity distribution, assuming a heavy composition of the primary cosmic rays over the whole energy range, while SIBYLL 2.3d and EPOS-LHC underpredict the number of muons in a large interval of multiplicity by more than 20% and 30%, respectively. The rate of high muon multiplicity events (Nμ > 100) obtained with QGSJET-II-04 and SIBYLL 2.3d is compatible with the data, while EPOS-LHC produces a significantly lower rate (55% of the measured rate). For both QGSJET-II-04 and SIBYLL 2.3d, the rate is close to the data when the composition is assumed to be dominated by heavy elements, an outcome compatible with the average energy Eprim ∼ 1017 eV of these events. This result places significant constraints on more exotic production mechanisms.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"70 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766441","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":"Fast simulation of cosmological neutral hydrogen based on the halo model","authors":"Pascal Hitz, Pascale Berner, Devin Crichton, John Hennig and Alexandre Refregier","doi":"10.1088/1475-7516/2025/04/003","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/003","url":null,"abstract":"Cosmological neutral hydrogen (HI) surveys provide a promising tomographic probe of the post-reionization era and of the standard model of cosmology. Simulations of this signal are crucial for maximizing the utility of these surveys. We present a fast method for simulating the cosmological distribution of HI based on a halo model approach. Employing the approximatePINOCCHIO code, we generate the past light cone of dark matter halos. Subsequently, the halos are populated with HI according to a HI-halo mass relation. The nature of 21 cm intensity mapping demands large-volume simulations with a high halo mass resolution. To fulfill both requirements, we simulate a past light cone for declinations between -15° and -35° in the frequency range from 700 to 800 MHz, matching HIRAX, the Hydrogen Intensity and Real-time Analysis eXperiment. We run PINOCCHIO for a 1 h-3 Gpc3 box with 67003 simulation particles. With this configuration, halos with masses as low as Mmin = 4.3 × 109 M⊙ are simulated, resulting in the recovery of more than 97% of the expected HI density. From the dark matter and HI past light cone, maps with a width of 5 MHz are created. To validate the simulation, we have implemented and present here an analytical dark matter and HI halo model in PyCosmo, a Python package tailored for theoretical cosmological predictions. We perform extensive comparisons between analytical predictions and the simulation for the mass function, mass density, power spectrum, and angular power spectrum for dark matter and HI. We find close agreement in the mass function and mass densities, with discrepancies within a few percent. For the three-dimensional power spectra and angular power spectra, we observe an agreement better than 10%. This approach is broadly applicable for forecasting and forward-modeling of dedicated intensity mapping experiments, such as HIRAX, as well as cosmological surveys with the SKA. Additionally, it is particularly well suited to be extended for cross-correlation studies. The PyCosmo halo model extension and simulation datasets are made publicly available.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"22 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744930","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":"Role of gravitational decoupling on theoretical insights of relativistic massive compact stars in the mass gap","authors":"S.K. Maurya, A. Errehymy, Ksh. Newton Singh, G. Mustafa and Saibal Ray","doi":"10.1088/1475-7516/2025/04/004","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/004","url":null,"abstract":"Advancements in theoretical simulations of mass gap objects, particularly those resulting from neutron star mergers and massive pulsars, play a crucial role in addressing the challenges of measuring neutron star radii. In the light of this, we have conducted a comprehensive investigation of compact objects, revealing that while the distribution of black hole masses varies based on formation mechanisms, they frequently cluster around specific values. For instance, the masses observed in GW190814 (23.2+1.1-1.0M⊙) and GW200210 (24.1+7.5-4.6M⊙) exemplify this clustering. We employed the gravitational decoupling approach within the framework of standard general relativity and thus focusing on the strange star model. This model highlights the effects of deformation adjusted by the decoupling constant and the bag function. By analyzing the mass-radius limits of mass gap objects from neutron star mergers and massive pulsars, we can effectively constrain the free parameters in our model, allowing us to predict the radii and moments of inertia for these objects. The mass-radius (M - R) and mass-inertia (M - I) profiles demonstrate the robustness of our models. It is shown that as the decoupling constant β increases from 0 to 0.1 and the bag constant ℬg decreases from 70 MeV/fm3 to 55 MeV/fm3, the maximum mass reaches Mmax = 2.87 M⊙ with a radius of 11.20 km. In contrast, for β = 0, the maximum mass is Mmax = 2.48 M⊙ with a radius of 10.69 km. Similarly, it has been exhibited that as β decreases to 0, the maximum mass peaks at Mmax = 2.95 M⊙ for ℬg = 55 MeV/fm3 with a radius of 11.32 km. These results not only exceed the observed masses of compact stars but also correlate with recent findings from gravitational wave events like GW190814 and GW200210, underscoring the relevance of our models in exploring compact objects in the universe.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"103 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744933","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":"Gauss-Bonnet dynamical compactification scenarios and their ghosts in the tensor sectors","authors":"Antonio De Felice and François Larrouturou","doi":"10.1088/1475-7516/2025/04/001","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/04/001","url":null,"abstract":"In a cosmological context, the Einstein-Gauss-Bonnet theory contains, in d + 4 dimensions, a dynamical compactification scenario in which the additional dimensions settle down to a configuration with a constant radion/scale factor. Sadly however this work demonstrates that such a quite appealing framework is plagued by instabilities, either from the background configuration's unsteadiness or the ghostly behaviors of the tensorial perturbations. New and stable solutions are found by relaxing one of the hypotheses defining the original compactification scenario. However, such configurations do not respect the current bounds on the speed of propagation of gravitational waves, and thus have to be discarded. Those results thus advocate for a comprehensive study of compactification scenarios in the Gauss-Bonnet framework, their stability, and the effects of matter inclusion.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"58 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744928","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}