Article
Astronomy & Astrophysics
A. Salehi, M. Yarahmadi, S. Fathi, Kazuharu Bamba
Summary: The study investigates the bulk flow of the local universe using Type Ia supernova data, finding agreement with the ΛCDM model at low redshifts but disagreement at high redshifts. The results support previous studies suggesting a large bulk flow in the universe.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
J. Muir, E. Baxter, V Miranda, C. Doux, A. Ferte, C. D. Leonard, D. Huterer, B. Jain, P. Lemos, M. Raveri, S. Nadathur, A. Campos, A. Chen, S. Dodelson, J. Elvin-Poole, S. Lee, L. F. Secco, M. A. Troxel, N. Weaverdyck, J. Zuntz, D. Brout, A. Choi, M. Crocce, T. M. Davis, D. Gruen, E. Krause, C. Lidman, N. MacCrann, A. Moller, J. Prat, A. J. Ross, M. Sako, S. Samuroff, C. Sanchez, D. Scolnic, B. Zhang, T. M. C. Abbott, M. Aguena, S. Allam, J. Annis, S. Avila, D. Bacon, E. Bertin, S. Bhargava, S. L. Bridle, D. Brooks, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, J. Carretero, R. Cawthon, M. Costanzi, L. N. da Costa, M. E. S. Pereira, S. Desai, H. T. Diehl, J. P. Dietrich, P. Doel, J. Estrada, S. Everett, A. E. Evrard, I Ferrero, B. Flaugher, J. Frieman, J. Garcia-Bellido, T. Giannantonio, R. A. Gruendl, J. Gschwend, G. Gutierrez, S. R. Hinton, D. L. Hollowood, K. Honscheid, B. Hoyle, D. J. James, T. Jeltema, K. Kuehn, N. Kuropatkin, O. Lahav, M. Lima, M. A. G. Maia, F. Menanteau, R. Miquel, R. Morgan, J. Myles, A. Palmese, F. Paz-Chinchon, A. A. Plazas, A. K. Romer, A. Roodman, E. Sanchez, V Scarpine, S. Serrano, I Sevilla-Noarbe, M. Smith, E. Suchyta, M. E. C. Swanson, G. Tarle, D. Thomas, C. To, D. L. Tucker, T. N. Varga, J. Weller, R. D. Wilkinson
Summary: The authors analyze DES data and propose a split growth-geometry approach to test physics beyond the ΛCDM model, combined with external data to constrain these quantities. Results show that combining DES with external data can constrain growth and geometry, but degeneracies with neutrino mass and intrinsic alignments are limiting factors.
Article
Astronomy & Astrophysics
M. Berti, M. Spinelli, B. S. Haridasu, M. Viel, A. Silvestri
Summary: In this study, we explore constraints on dark energy and modified gravity using forecasted 21cm intensity mapping measurements. We find that adding the power spectrum of the 21cm signal to the latest CMB data significantly tightens the constraints on certain parameters. We also demonstrate the importance of tomography in improving the constraining power on theories beyond the standard ΛCDM model.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Albin Joseph, Rajib Saha
Summary: The next-generation CMB satellite missions can provide precise constraints on cosmological parameters. However, these constraints may weaken without attributing dark energy to a cosmological constant. Models involving interaction between dark energy and dark matter can alleviate the cosmic coincidence problem. In this study, the ability of future CMB and BAO experiments to constrain interacting dark energy models is tested, showing improved constraints when combined with additional data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Eleonora Di Valentino, William Giare, Alessandro Melchiorri, Joseph Silk
Summary: In this study, the global agreement between observations of the cosmic microwave background (CMB) from the Atacama Cosmology Telescope and the Planck satellite is examined in different cosmological models with additional parameters. The Suspiciousness statistic is used to quantify the tension between the two experiments. Results show that the tension is reduced to 1.8 sigma when the effective number of relativistic particles is lower than the standard value, and ranges between 2.3 sigma and 3.5 sigma in other extended models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Shengqi Yang, Rachel S. Somerville, Anthony R. Pullen, Gergo Popping, Patrick C. Breysse, Abhishek S. Maniyar
Summary: Submillimeter emission lines are important for tracing the cold gas and ionized environments of galaxies, and for future line intensity mapping surveys. Physics-based simulations predicting emission lines from different interstellar medium phases are crucial for understanding galaxy physical conditions. This study presents a framework for creating mock submillimeter line intensity maps and shows significant differences in predicted star formation rate and line emission scaling relations compared to empirical relations. These differences impact key summary statistics used in intensity mapping, emphasizing the need for realistic models in forecasting the capabilities of future surveys.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
D. Jackson, R. Bufalo
Summary: In this study, we investigate the growth of structures within the Deser-Woodard nonlocal theory and its extension to bouncing cosmology scenarios. Our findings show that the observable structure growth rate, f & sigma;8, in a vacuum-dominated universe is finite within the redshift range of 0 < z < 2, contrary to previous literature. We also evaluate the evolution of f & sigma;8 near the bouncing point in different bouncing cosmologies, revealing the seeds of large-scale structures resulting from non-local effects.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Eleonora Di Valentino, Nils A. Nilsson, Mu-In Park
Summary: This study proposes a renormalizable, higher derivative, Lorentz-violating quantum gravity model without ghost problems known as Hoava gravity. Furthermore, a Hoava gravity-based dark energy (HDE) model is proposed by identifying the additional contributions from Lorentz-violating terms as an effective energy-momentum tensor in Einstein equation. The results show a preference for non-flat universes in the cosmic microwave background, baryon acoustic oscillation, and supernova Ia data tests, aligning with the cosmic concordance model.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Rodrigo Calderon, Arman Shafieloo, Dhiraj Kumar Hazra, Wuhyun Sohn
Summary: In this study, Gaussian Processes are used to perform a non-parametric consistency test on the anisotropies in the Cosmic Microwave Background. The results show no statistically significant deviations in the residuals across different datasets. Additionally, interesting features in the polarization measurements are discovered, indicating potential inconsistencies between CamSpec and Planck/ACT.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
William Giare, Fabrizio Renzi, Alessandro Melchiorri, Olga Mena, Eleonora Di Valentino
Summary: This paper investigates how improvements in future cosmic microwave background and baryon acoustic oscillation measurements can provide constraints on extensions of the standard model of elementary particles. The research demonstrates that future cosmic observations can greatly enhance the limits on the mass of hot dark matter and support analyses of axion, neutrino, and primordial light element properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Nuclear
Peng-Ju Wu, Jing-Zhao Qi, Xin Zhang
Summary: Density decreases with an increase in thickness, and proper length of the shell steadily decreases. The energy of the shell increases towards the outer surface, indicating that the outer boundary is denser.
Article
Physics, Multidisciplinary
Daniel Frolovsky, Sergei V. V. Ketov, Sultan Saburov
Summary: In this study, new (generalized) E-type alpha-attractor models are proposed and studied in order to explain the formation of primordial black holes (PBHs). The models involve three different phases of inflation, and numerical calculations are used to obtain the power spectrum of scalar perturbations and PBH masses. It is found that for certain parameter values, asteroid-size PBHs with masses ranging from 10^17 to 10^19 grams can be formed, which may serve as a candidate for dark matter in the present Universe. Furthermore, it is suggested that the gravitational waves produced by the formation of PBHs can potentially be detected by future space-based gravitational interferometers.
FRONTIERS IN PHYSICS
(2022)
Article
Astronomy & Astrophysics
H. R. M. Zarandi, E. Ebrahimi
Summary: This paper studies the cosmic age problem in holographic and generalized ghost dark energy models, and finds that non-linear interactions can alleviate the age problem. By analyzing age tests and data sets, the study also discovers a new bound for a parameter and shows that the generalized ghost dark energy can completely alleviate the cosmic age problem.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
H. R. M. Zarandi, E. Ebrahimi
Summary: This paper discusses the cosmic age problem in the case of the ghost dark energy model and uses observational data to constrain the free parameter space of the models. It is found that in one case the age problem is completely resolved, while in the other two cases some constraints on the models are required. Additionally, other properties of these three models, such as the ability to cross the phantom line and the stability against cosmic perturbations, are investigated.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2022)
Article
Astronomy & Astrophysics
Anup Kumar Singha, Alok Sardar, Ujjal Debnath
Summary: In this article, we have attempted to reform the symmetric f(Q) gravity by studying modified Teleparallel Gravity theories such as f(P), f(T), f(R), f(R,T), Einstein-Aether (EA), f(G), and f(R, G). We discussed their important role in the expansion of the universe and derived f(Q) in terms of Q. By comparing the energy densities of f(Q) and other modified gravity theories, we graphically characterized the relationship between Q and f(Q) for each model. We also analyzed the evolution of the universe using cosmological parameters like the deceleration parameter q, the equation of state parameter ωDE, and the squared speed of sound parameter vs2 for each model. Additionally, we examined the freezing and thawing zones in the ωDE-ωDE plane.
PHYSICS OF THE DARK UNIVERSE
(2023)
Article
Astronomy & Astrophysics
Xue Zhang, Qing-Guo Huang, Xiao-Dong Li
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2019)
Article
Astronomy & Astrophysics
Feng Fang, Jaime Forero-Romero, Graziano Rossi, Xiao-Dong Li, Long-Long Feng
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2019)
Article
Astronomy & Astrophysics
Jianming Zhang, Qiyue Qian, Yiqing Guo, Xin Wang, Xiao-Dong Li
Summary: The study investigates the role of gravitational waves in the heat death of the Universe, finding that they lead to energy dissipation in dynamical systems, transitioning to a state of rest and death. Energy loss due to gravitational wave emission in dark matter systems is estimated through N-body simulations, though the analysis may be invalidated by multiple unknown factors.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ziyong Wu, Zhenyu Zhang, Shuyang Pan, Haitao Miao, Xiaolin Luo, Xin Wang, Cristiano G. Sabiu, Jaime Forero-Romero, Yang Wang, Xiao-Dong Li
Summary: Researchers have developed a deep learning technique to infer the nonlinear velocity field from the dark matter density field. Their analysis shows that neural networks may have an overwhelming advantage over perturbation theory in reconstructing velocity or momentum fields.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Mi-Xiang Lan, Xue-Feng Wu, Zi-Gao Dai
Summary: Synchrotron emission polarization is highly sensitive to magnetic field configuration, with recent developments in mixed magnetic field models demonstrating similar polarization properties to purely ordered magnetic field models. Statistical analysis shows most GRBs have non-zero polarization degrees, with brighter GRBs either favoring toroidal mixed magnetic field models or aligned purely ordered magnetic field models. Additionally, application of these findings to POLAR data suggests a preference for certain magnetic field configurations with specific xi(B) parameter values.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Shuren Zhou, Zhenjie Liu, Qinglin Ma, Yu Liu, Le Zhang, Xiao-Dong Li, Yang Wang, Xin Wang, Yu Yu, Hao-Ran Yu, Yi Zheng
Summary: This study investigates the impacts of massive neutrinos on the cosmic velocity fields and finds that the vorticity power spectra are highly sensitive to the mass sum of neutrinos, offering potential signatures for detecting massive neutrinos. The study also quantitatively tests the sensitivity of the density and velocity power spectra to the neutrino mass sum, with the vorticity spectrum showing the highest sensitivity. The results highlight the importance of peculiar velocity field measurements, particularly of vorticity and divergence components, in determining neutrino mass and mass hierarchy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Yang Wang, Nicola R. Napolitano, Weiguang Cui, Xiao-Dong Li, Alexander Knebe, Chris Power, Frazer Pearce, Lin Tang, Gustavo Yepes, Xi Kang
Summary: This work presents a model to describe the star formation histories (SFHs) of individual galaxies from three simulations. The model divides SFHs into two components: the 'main sequence' and the 'variation', which are generated by tracing the history of the SFR-M-* main sequence and reproducing scatter around it using fractional Brownian motions. The study finds that the evolution of the main sequence varies between simulations, fractional Brownian motions can reproduce many features of SFHs but discrepancies still exist, and variations and mass-loss rate are crucial for reconstructing the SFHs of the simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
R. Y. Guan, M. X. Lan
Summary: With the accumulation of polarization data, the polarization models of gamma-ray bursts can be tested. By predicting the time-integrated polarizations of 37 observed bursts and matching them with the observed values, it is found that the synchrotron-emission model with a large-scale ordered magnetic field can explain the observed polarizations well. However, there are challenges to the model due to the lower predicted polarizations of two bursts. Therefore, more accurate multiband polarization observations are needed to test the models of the gamma-ray burst prompt phase.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Haitao Miao, Yan Gong, Xuelei Chen, Zhiqi Huang, Xiao-Dong Li, Hu Zhan
Summary: As a Stage IV space-based telescope, the China Space Station Telescope (CSST) efficiently explores the Universe through simultaneous photometric and spectroscopic surveys. This study investigates several powerful CSST cosmological probes and demonstrates their capability to significantly improve the precision of current observations. By including various surveys, CSST can achieve 1% accuracy in omega(m) and sigma(8), and 5% and 20% accuracy in w(0) and w(a) respectively. CSST's multi-probe surveys provide powerful tools for exploring the Universe and advancing cosmological research.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Liang Xiao, Zhiqi Huang, Yi Zheng, Xin Wang, Xiao-Dong Li
Summary: The tomographic Alcock-Paczynski (AP) method is a powerful tool for calibrating cosmology using the redshift evolution of anisotropic clustering. However, redshift errors can affect the resolution of nonlinear structure and contaminate the results. This study investigates how redshift errors propagate to cosmological parameters in tomographic AP analysis and finds that the method remains useful for future spectroscopic surveys.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Hao-Bing Wang, Mi-Xiang Lan
Summary: The rotations of the polarization angle with time can lead to the depolarization of the time-integrated polarization. A magnetic reconnection model is used to investigate the polarizations of gamma-ray burst prompt emission. The rotations of the polarization angles are due to changes in the observed image of the emitting region before being averaged over the equal arrival time surface.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Jiacheng Ding, Yunlei Huang, Xiao-Dong Li, Xin Wang, Yang Wang, Lili Yang
Summary: Since the discovery of neutrinos, their origin has remained a mystery until their association with TXS 0506+056. The recent publication of the fourth catalogue of active galactic nuclei (4LAC) has provided useful data to study these phenomena, particularly the blazars, which constitute the majority of the objects in the catalogue. By utilizing machine learning algorithms and deep learning techniques, researchers have achieved impressive success in classifying blazars, including the challenging task of classifying blazars of uncertain type (BCUs). The study also reveals a potential association between blazars and neutrinos, suggesting the possibility of using neutrinos as a feature for object classification in the future.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Mi-Xiang Lan, Zi-Gao Dai
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Mi-Xiang Lan, Rui Xue, Dingrong Xiong, Wei-Hua Lei, Xue-Feng Wu, Zi-Gao Dai
ASTROPHYSICAL JOURNAL
(2019)
Article
Astronomy & Astrophysics
Cristiano G. Sabiu, Ben Hoyle, Juhan Kim, Xiao-Dong Li
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2019)