Article
Astronomy & Astrophysics
William L. Matthewson, Dennis Stock, Ruth Durrer
Summary: In this paper, we introduce the concept of "redshift fluctuation" as a gauge-invariant cosmological observable and provide its fully relativistic expression. The angular power spectrum of this variable is analyzed to study the relevance of different relativistic contributions and to compare it with conventional observable galaxy number count fluctuations. Fisher forecasts are performed to investigate the utility of this variable for future spectroscopic surveys, with a focus on the dependence of the results on the size of the redshift bins and the analysis cutoff.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Pedro Carrilho, Chiara Moretti, Benjamin Bose, Katarina Markovic, Alkistis Pourtsidou
Summary: Interacting dark energy models are proposed as alternatives to ACDM, and forthcoming galaxy clustering surveys will provide constraints on these models. This study compares three approaches of modeling non-linearities, considering a model with a simple 1-parameter extension to wCDM. Analysis using simulated data shows that the EFTofLSS-based model is better at describing data up to smaller scales and extracting more information, forecasting uncertainties on the dark energy equation of state and interaction parameter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Wilmar Cardona, David Figueruelo
Summary: We investigated a cosmological model that allows momentum transfer between dark matter and dark energy. The interaction in the dark sector mainly affects perturbations on small scales but does not resolve the H0 tension. Cosmological constraints confirm the contribution of momentum transfer to the a-8 discrepancy in the standard model. Future galaxy surveys will provide important information for testing models allowing momentum transfer in the dark sector.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Peng-Ju Wu, Xin Zhang
Summary: The 21 cm intensity mapping technique is a powerful tool for measuring dark-energy parameters, with interferometers showing great potential for constraining cosmological parameters. The Tianlai cylinder array alone can achieve precision cosmology standards, while SKA1-MID performs well in constraining dynamical dark energy. Simulated 21 cm IM data can break parameter degeneracies and provide tighter constraints. Combining different observations offers promising survey strategies. The amplitude of residual foreground contamination significantly impacts constraint results.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Wilmar Cardona, M. A. Sabogal
Summary: Interesting discrepancies in cosmological parameters challenge the success of the ACDM model. The Hubble constant and matter clustering strength derived from various measurements are higher/lower than those inferred from the Cosmic Microwave Background (CMB) in the context of ACDM. In this study, we propose a Dark Energy (DE) model with an evolving equation of state and constant sound speed squared to address these discrepancies. By considering the impact of DE sound speed on gravitational potential evolution, we find good agreement between our results and low redshift probes, but tension with BBN constraints in the case of baryon energy density.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Fei Qin, David Parkinson, Sungwook E. Hong, Cristiano G. Sabiu
Summary: The distribution of matter can teach us about dark matter, dark energy, and gravity. To understand the Universe's matter, we rebuild the density and velocity fields from galaxies. Using simulated halos as proxies for galaxies, a convolutional neural network, V-net, is used to reconstruct the fields. The V-net provides better fits to the density field and improved predictions for velocity amplitudes, but reduces the precision of the estimated β parameter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Andrea Oddo, Federic Rizzo, Emiliano Sefusatti, Cristiano Porciani, Pierluigi Monaco
Summary: In this study, a joint likelihood analysis of the halo power spectrum and bispectrum in real space was conducted using a large set of numerical simulations and halo mock catalogs. Constraints on bias and cosmological parameters were derived, and a reference bias model dependent on seven parameters was selected based on the Deviance Information Criterion. This model accurately recovers three selected cosmological parameters even for extreme simulation volumes, demonstrating the importance of considering relations among bias parameters and full covariance estimation from mock catalogs.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Miguel Aparicio Resco, Antonio L. Maroto
Summary: FARO is a new public Python code that computes the Fisher matrix for galaxy survey observables, allowing for tomographic and model-independent analysis, and forecasting the sensitivity of future galaxy surveys like DESI, Euclid, J-PAS and LSST.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Samuel Brieden, Hector Gil-Marin, Licia Verde
Summary: Recent works have shown that fitting the full power spectrum signal directly leads to tighter constraints on cosmological parameters, with an additional effective parameter capturing the same amount of information. The ShapeFit extension of the classic approach delivers equivalent results to the full modelling approach, being more model independent and providing an understanding of the extra cosmological information origin, while allowing robust control on observational systematics.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Yufei Zhang, Mingjing Chen, Zhonglue Wen, Wenjuan Fang
Summary: This study examines the potential of the galaxy cluster sample from the Chinese Space Station Telescope (CSST) survey to constrain dark energy properties. The study finds that about 4.1 x 10^5 clusters can be detected by CSST in the redshift range of 0 <= z <= 1.5. By constraining the observable-mass scaling relation, the study suggests the importance of avoiding bias in dark energy parameters.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. Benetti, H. A. Borges, C. Pigozzo, S. Carneiro, J. S. Alcaniz
Summary: The observational viability of a class of interacting dark energy (iDE) models was investigated, with the best-fit favoring a positive interaction and ruling out the non-interacting case. A significant anti-correlation between the interaction parameter and the universe density curvature was found when considering a non-zero spatial curvature. The influence of the SHOES prior on the expansion rate had a significant impact on the results of the iDE model, but did not considerably change standard cosmology predictions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Javier E. Gonzalez, Micol Benetti, Rodrigo von Marttens, Jailson Alcaniz
Summary: The paper discusses the implications of joint analyses using current data sets, focusing on non-flat universe and extensions of the standard cosmological model. Results suggest potential misleading conclusions in joint analysis, highlighting the dependence on spatial curvature and dark energy parameterizations.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
A. Fumagalli, A. Saro, S. Borgani, T. Castro, M. Costanzi, P. Monaco, E. Munari, E. Sefusatti, A. Amara, N. Auricchio, A. Balestra, C. Bodendorf, D. Bonino, E. Branchini, J. Brinchmann, V. Capobianco, C. Carbone, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, C. J. Conselice, L. Corcione, A. Costille, M. Cropper, H. Degaudenzi, M. Douspis, F. Dubath, S. Dusini, A. Ealet, P. Fosalba, E. Franceschi, P. Franzetti, M. Fumana, B. Garilli, C. Giocoli, F. Grupp, L. Guzzo, S. V. H. Haugan, H. Hoekstra, W. Holmes, F. Hormuth, K. Jahnke, A. Kiessling, M. Kilbinger, T. Kitching, M. Kuemmel, M. Kunz, H. Kurki-Suonio, R. Laureijs, P. B. Lilje, I. Lloro, E. Maiorano, O. Marggraf, K. Markovic, R. Massey, M. Meneghetti, G. Meylan, L. Moscardini, S. M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, V. Pettorino, S. Pires, M. Poncet, L. Popa, L. Pozzetti, F. Raison, J. Rhodes, M. Roncarelli, E. Rossetti, R. Saglia, R. Scaramella, P. Schneider, A. Secroun, G. Seidel, S. Serrano, C. Sirignano, G. Sirri, A. N. Taylor, I. Tereno, R. Toledo-Moreo, E. A. Valentijn, L. Valenziano, Y. Wang, J. Weller, G. Zamorani, J. Zoubian, M. Brescia, G. Congedo, L. Conversi, S. Mei, M. Moresco, T. Vassallo
Summary: The study investigates the uncertainties in cosmological parameter constraints derived from cluster number counts in the context of the Euclid survey, focusing on the contributions of shot-noise and sample variance. By analyzing Euclid-like light cones and validating the analytical model of the covariance matrix, the study shows that the Gaussian likelihood with full covariance is necessary for unbiased inference of cosmological parameters without underestimating errors. The study also highlights the importance of considering the cosmology dependence of the covariance matrix for accurate parameter constraints.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
J. Diehl, J. Weller
Summary: This paper explores the potential of current and upcoming cosmological surveys to constrain the mass and abundance of ultra-light axions (ULAs) using galaxy cluster number counts. Galaxy cluster counts are a robust probe of structure formation in the Universe and are sensitive to linear matter perturbations. The study reveals degeneracies in the ULA mass vs. abundance parameter space, indicating that galaxy cluster counts may offer valuable insights into the properties of ULAs.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Rafael C. Nunes, Sunny Vagnozzi, Suresh Kumar, Eleonora Di Valentino, Olga Mena
Summary: In this study, we explore the role of redshift-space galaxy clustering data in constraining nongravitational interactions between dark energy (DE) and dark matter (DM). By combining the data from galaxy power spectrum and Baryon Acoustic Oscillation (BAO) measurements with Cosmic Microwave Background (CMB) data, we obtain one of the strongest limits on the DM-DE coupling strength. Contrary to previous observations, we find that the combination of CMB and full-shape (FS) galaxy power spectrum returns tighter constraints compared to the combination of CMB and BAO, indicating valuable additional information in the broadband of the power spectrum. Our results highlight the critical role of redshift-space galaxy clustering measurements in precision cosmology.
Article
Chemistry, Medicinal
Sakineh Poorhosein Fookolaee, Samad Karkhah, Mahdiye Saadi, Subho Majumdar, Ahmad Karkhah
CURRENT COMPUTER-AIDED DRUG DESIGN
(2020)
Editorial Material
Chemistry, Medicinal
Subhash C. Basak, Subhabrata Majumdar, Marjan Vracko, Ashesh Nandy, Apurba Bhattacharjee
CURRENT COMPUTER-AIDED DRUG DESIGN
(2020)
Article
Computer Science, Information Systems
Abhik Ghosh, Subhabrata Majumdar
IEEE TRANSACTIONS ON INFORMATION THEORY
(2020)
Article
Astronomy & Astrophysics
Sandeep Kumar Acharya, Subhabrata Majumdar, Biman B. Nath
Summary: This study explores the potential impact of high-energy electrons in the lobes of radio galaxies on radio, X-rays, and cosmic microwave background radiation, using an improved model to estimate observational parameters. The research indicates that non-thermal SZ distortions in radio galaxy lobes may have a non-negligible effect on observations, especially for small and young galaxies in cluster environments.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Statistics & Probability
Subhabrata Majumdar, Snigdhansu Chatterjee
Summary: This paper proposes using data dependent weights in association with multivariate sign functions, which improves the efficiency in estimation and inference while preserving robustness. The paper also demonstrates the applications of robust location estimation, robust principal component analysis, robust sufficient dimension reduction, and functional outlier detection.
JOURNAL OF MULTIVARIATE ANALYSIS
(2022)
Article
Astronomy & Astrophysics
Sandeep Kumar Acharya, Subhabrata Majumdar, Biman B. Nath
Summary: Current and upcoming experiments on cosmic microwave background (CMB) anisotropies can explore the fluctuations caused by evolving lobes of giant radio galaxies. By considering the non-thermal electron distribution, the CMB angular power spectrum can be inferred accurately. It is found that the non-thermal y-distortion is within the limits set by the cosmic background explorer. Detection of the non-thermal SZ power spectrum can provide constraints on the jet luminosity and mass dependence of black hole scaling relations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Asif Iqbal, Subhabrata Majumdar, Biman B. Nath, Suparna Roychowdhury
Summary: In this study, two heating models for active galactic nuclei (AGN) are implemented to determine their consistency with observables of the intracluster medium (ICM). The results show that both heating processes can produce comparable thermal profiles of the ICM, with thermal conduction playing a crucial role in transferring energy beyond the central regions. The required AGN power scales with cluster mass and the AGN luminosity is comparable with the observed radio jet power. Additionally, the fraction of AGN mechanical luminosity at 0.02 r(500) is less than 0.05%.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Sandeep Kumar Acharya, Subhabrata Majumdar
Summary: We discuss the anisotropy of the cosmic microwave background (CMB) due to the kinetic Sunyaev-Zel'dovich (kSZ) effect from ionized bubbles around individual quasars before the reionization of the Universe. The kSZ distortion power spectrum from the bubbles is found to be sub-dominant to kSZ from patchy reionization driven by galaxies. However, the shape of the two power spectra are different, making it possible to distinguish them using template-fitting in future surveys like CMB-HD. Next, we show that a single quasar bubble's imprint on the CMB can be detected in a high-resolution effort like CMB-HD, and its joint analysis with other observations can provide additional information to break parameter degeneracies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Subhabrata Majumdar, Saonli Basu, Matt McGue, Snigdhansu Chatterjee
Summary: In this study, a resampling-based fast variable selection technique is proposed for detecting relevant single nucleotide polymorphisms (SNP) in a multi-marker mixed effect model. By jointly modeling genetic variants within a gene or pathway, better detection of associated genetic variants, especially those with weak effects, can be achieved. Numerical studies show that the proposed method is more effective in detecting trait-associated SNPs than single-marker analysis or model selection methods that ignore familial dependency structure.
SCIENTIFIC REPORTS
(2023)
Review
Astronomy & Astrophysics
Surajit Paul, Ruta Kale, Abhirup Datta, Aritra Basu, Sharanya Sur, Viral Parekh, Prateek Gupta, Swarna Chatterjee, Sameer Salunkhe, Asif Iqbal, Mamta Pandey-Pommier, Ramij Raja, Majidul Rahaman, Somak Raychaudhury, Biman B. Nath, Subhabrata Majumdar
Summary: Diffuse radio emission has been detected in many galaxy clusters and groups, revealing the presence of cosmological magnetic fields and relativistic particles. The observation of this radio emission is limited by the sensitivity and frequency of the instruments, especially for lower-mass systems.
JOURNAL OF ASTROPHYSICS AND ASTRONOMY
(2023)
Proceedings Paper
Computer Science, Artificial Intelligence
Subhabrata Majumdar, Snigdhansu Chatterjee
Summary: In the context of supervised parametric models, the concept of e-values is introduced to measure the proximity between the sampling distribution of parameter estimates in a model trained on a subset of features and that of the model trained on all features. E-values can be applied to a wide range of parametric models. By using data depths and a resampling-based algorithm, a feature selection procedure using e-values is implemented, which requires fitting only the full model and evaluating p + 1 models for a p-dimensional feature space. Experimental results show that the e-values method is a promising general alternative for feature selection compared to existing model-specific methods.
INTERNATIONAL CONFERENCE ON MACHINE LEARNING, VOL 162
(2022)
Article
Automation & Control Systems
Subhabrata Majumdar, George Michailidis
Summary: In this work, a statistical framework based on Gaussian graphical models is proposed for the integration of multi-layer and multi-source biological or disease process data. The methodology decomposes the multi-layer problem into two-layer problems and uses neighborhood selection and group-penalized regression to estimate model parameters. Debiasing technique and asymptotic distributions are developed for inter-layer directed edge weights. Furthermore, global and simultaneous testing procedures for these edge weights are established. The proposed methodology is evaluated on synthetic and real data.
JOURNAL OF MACHINE LEARNING RESEARCH
(2022)
Article
Computer Science, Information Systems
Victor A. E. Farias, Felipe T. Brito, Cheryl Flynn, Javam C. Machado, Subhabrata Majumdar, Divesh Srivastava
PROCEEDINGS OF THE VLDB ENDOWMENT
(2020)
Review
Chemistry, Multidisciplinary
Subhash C. Basak, Subhabrata Majumdar, Claudiu Lungu
CROATICA CHEMICA ACTA
(2020)
Article
Astronomy & Astrophysics
Sayan Mandal, Subhabrata Majumdar, Vikram Rentala, Ritoban Basu Thakur