English
Related papers

Related papers: Constraints on a Bianchi type I spacetime extensio…

200 papers

Recent cosmological measurements suggest the possibility of an anisotropic universe. As a result, the Bianchi Type I model, being the simplest anisotropic extension to the standard Friedmann-Lema\^itre-Robertson-Walker metric has been…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-05 Boris Hoi-Lun Ng , Ming-Chung Chu

Cosmic Microwave Background (CMB) independent approaches are frequently used in the literature to provide estimates of Hubble constant ($H_0$). In this work, we report CMB independent constraints on $H_0$ in an anisotropic extension of…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-13 Vikrant Yadav

In recent years, upper limits on the cosmic microwave background (CMB) anisotropies combined with predictions made by theories of galaxy formation, have been extremely powerful in ruling out purely baryonic dark matter (BDM) universes.…

Astrophysics · Physics 2009-11-06 Louise M Griffiths , Alessandro Melchiorri , Joseph Silk

We use new cosmic microwave background (CMB) primary temperature and polarization anisotropy measurements from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) to test foundational assumptions of the standard cosmological model…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-25 Erminia Calabrese , J. Colin Hill , Hidde T. Jense , Adrien La Posta , Irene Abril-Cabezas , Graeme E. Addison , Peter A. R. Ade , Simone Aiola , Tommy Alford , David Alonso , Mandana Amiri , Rui An , Zachary Atkins , Jason E. Austermann , Eleonora Barbavara , Nicola Barbieri , Nicholas Battaglia , Elia Stefano Battistelli , James A. Beall , Rachel Bean , Ali Beheshti , Benjamin Beringue , Tanay Bhandarkar , Emily Biermann , Boris Bolliet , J Richard Bond , Valentina Capalbo , Felipe Carrero , Shi-Fan Chen , Grace Chesmore , Hsiao-mei Cho , Steve K. Choi , Susan E. Clark , Nicholas F. Cothard , Kevin Coughlin , William Coulton , Devin Crichton , Kevin T. Crowley , Omar Darwish , Mark J. Devlin , Simon Dicker , Cody J. Duell , Shannon M. Duff , Adriaan J. Duivenvoorden , Jo Dunkley , Rolando Dunner , Carmen Embil Villagra , Max Fankhanel , Gerrit S. Farren , Simone Ferraro , Allen Foster , Rodrigo Freundt , Brittany Fuzia , Patricio A. Gallardo , Xavier Garrido , Martina Gerbino , Serena Giardiello , Ajay Gill , Jahmour Givans , Vera Gluscevic , Samuel Goldstein , Joseph E. Golec , Yulin Gong , Yilun Guan , Mark Halpern , Ian Harrison , Matthew Hasselfield , Adam He , Erin Healy , Shawn Henderson , Brandon Hensley , Carlos Hervías-Caimapo , Gene C. Hilton , Matt Hilton , Adam D. Hincks , Renée Hložek , Shuay-Pwu Patty Ho , John Hood , Erika Hornecker , Zachary B. Huber , Johannes Hubmayr , Kevin M. Huffenberger , John P. Hughes , Margaret Ikape , Kent Irwin , Giovanni Isopi , Neha Joshi , Ben Keller , Joshua Kim , Kenda Knowles , Brian J. Koopman , Arthur Kosowsky , Darby Kramer , Aleksandra Kusiak , Alex Lague , Victoria Lakey , Massimiliano Lattanzi , Eunseong Lee , Yaqiong Li , Zack Li , Michele Limon , Martine Lokken , Thibaut Louis , Marius Lungu , Niall MacCrann , Amanda MacInnis , Mathew S. Madhavacheril , Diego Maldonado , Felipe Maldonado , Maya Mallaby-Kay , Gabriela A. Marques , Joshiwa van Marrewijk , Fiona McCarthy , Jeff McMahon , Yogesh Mehta , Felipe Menanteau , Kavilan Moodley , Thomas W. Morris , Tony Mroczkowski , Sigurd Naess , Toshiya Namikawa , Federico Nati , Simran K. Nerval , Laura Newburgh , Andrina Nicola , Michael D. Niemack , Michael R. Nolta , John Orlowski-Scherer , Luca Pagano , Lyman A. Page , Shivam Pandey , Bruce Partridge , Karen Perez Sarmiento , Heather Prince , Roberto Puddu , Frank J. Qu , Damien C. Ragavan , Bernardita Ried Guachalla , Keir K. Rogers , Felipe Rojas , Tai Sakuma , Emmanuel Schaan , Benjamin L. Schmitt , Neelima Sehgal , Shabbir Shaikh , Blake D. Sherwin , Carlos Sierra , Jon Sievers , Cristóbal Sifón , Sara Simon , Rita Sonka , David N. Spergel , Suzanne T. Staggs , Emilie Storer , Kristen Surrao , Eric R. Switzer , Niklas Tampier , Leander Thiele , Robert Thornton , Hy Trac , Carole Tucker , Joel Ullom , Leila R. Vale , Alexander Van Engelen , Jeff Van Lanen , Cristian Vargas , Eve M. Vavagiakis , Kasey Wagoner , Yuhan Wang , Lukas Wenzl , Edward J. Wollack , Kaiwen Zheng

In this letter, we report the observational constraints on a Bianchi type I anisotropic extension of $w$CDM model with spatial curvature from observational data including Baryon Acoustic Oscillations (BAO), Cosmic chronometers (CC), Big…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-21 Vikrant Yadav , Rajpal , Pardeep , Manish Yadav , Santosh Kumar Yadav

I deduce an exact and analytic Bianchi type I solution of Einsteins field equations, which generalizes the isotropic LambdaCDM universe model to a corresponding model with anisotropic expansion. The main point of the article is to present…

General Relativity and Quantum Cosmology · Physics 2024-06-17 Øyvind G. Grøn

Anisotropic cosmological models have been gaining attention due to various observational hints of large-scale anisotropies. One of the most surprising evidences for the latter is the discovery of a dipole-like directional variation in…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-08 Boris Hoi-Lun Ng , Ming-Chung Chu

We examine the constraints that can be obtained on standard cold dark matter models from the most currently used data set: CMB anisotropies, type Ia supernovae and the SDSS luminous red galaxies. We also examine how these constraints are…

Astrophysics · Physics 2015-05-13 L. D. Ferramacho , A. Blanchard , Y. Zolnierowski

We construct a generalization of the standard $\Lambda$CDM model, wherein we simultaneously replace the spatially flat Robertson-Walker metric with its simplest anisotropic generalization (LRS Bianchi I metric), and couple the cold dark…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-01 Ozgur Akarsu , John D. Barrow , N. Merve Uzun

We use data from the ARGO cosmic microwave background (CMB) anisotropy experiment to constrain cosmogonies. We account for the ARGO beamwidth and calibration uncertainties, and marginalize over the offset removed from the data. Our derived…

There are evidences that the cosmic microwave background (CMB) large-angle anomalies imply a departure from statistical isotropy and hence from the standard cosmological model. We propose a LCDM model extension whose dark energy component…

Astrophysics · Physics 2008-11-26 Davi C. Rodrigues

We study the Bianchi-I cosmological model motivated by signals of statistical isotropy violation seen in cosmic microwave background (CMB) observations and others. To that end, we consider various kinds of anisotropic matter that source…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Anshul Verma , Sanjeet K. Patel , Pavan K. Aluri , Sukanta Panda , David F. Mota

We compare the latest observations of Cosmic Microwave Background (CMB) Anisotropies with the theoretical predictions of the standard scenario of structure formation. Assuming a primordial power spectrum of adiabatic perturbations we found…

Astrophysics · Physics 2009-11-07 Alessandro Melchiorri , Carolina Odman

We use updated Type Ia Pantheon+ supernova, baryon acoustic oscillation, and Hubble parameter (now also accounting for correlations) data, as well as new reverberation-measured C IV quasar data, and quasar angular size, H II starburst…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-19 Shulei Cao , Bharat Ratra

Although the new era of high precision cosmology of the cosmic microwave background (CMB) radiation improves our knowledge to understand the infant as well as the presentday Universe, it also leads us to question the main assumption of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Esra Russell , Can Battal Kilinc , Oktay K. Pashaev

Cosmic microwave background anisotropies encode crucial information about the early Universe and fundamental cosmological physics. Although the standard $\Lambda$CDM model provides a successful description of cosmic evolution, persistent…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Yang Han , Lu Chen , Guo-Hao Li , Pei-Yuan Xu

Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 Chan-Gyung Park , Bharat Ratra

The recent data from the Boomerang and MAXIMA-1 balloon flights have marked the beginning of the precision era of Cosmic Microwave Background anisotropy (CMB) measurements. We investigate the observational constraints from the current CMB…

Astrophysics · Physics 2009-10-31 William H. Kinney , Alessandro Melchiorri , Antonio Riotto

The isotropy and homogeneity of our Universe are the cardinal principles of modern cosmology built on the definition of metric through the prescription by Friedmann-Lema$\hat{i}$tre-Robertson-Walker (FLRW). From the aspects of geometry, the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-03 Jiwon Park , Sourav Mridha , Dukjae Jang , Mayukh R. Gangopadhyay , Myung-Ki Cheoun

We use Owens Valley Radio Observatory (OVRO) cosmic microwave background (CMB) anisotropy data to constrain cosmological parameters. We account for the OVRO beamwidth and calibration uncertainties, as well as the uncertainty induced by the…

‹ Prev 1 2 3 10 Next ›