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Related papers: An Anisotropic Model for the Universe

200 papers

The presence of dark energy in the Universe is inferred directly from the accelerated expansion of the Universe, and indirectly, from measurements of cosmic microwave background (CMB) anisotropy. Dark energy contributes about 2/3 of the…

Astrophysics · Physics 2011-05-05 Dragan Huterer , Michael S. Turner

Despite having a reasonably successful account of accelerated cosmology, understanding the early evolution of Universe has always been difficult for mankind. Our promising strategy is based on a novel class of symmetric teleparallel…

General Relativity and Quantum Cosmology · Physics 2022-09-12 L. Anjana Devi , S. Surendra Singh , Leishingam Kumrah , Md Khurshid Alam

Cosmic microwave background (CMB) observations provide in principle a high-precision test of models which are motivated by M theory. We set out the framework of a program to compute the tensor anisotropies in the CMB that are generated in…

Astrophysics · Physics 2009-11-07 Bernard Leong , Anthony Challinor , Roy Maartens , Anthony Lasenby

Assuming that the Universe at higher redshifts (z \sim 4 and beyond) is consistent with LCDM model as constrained by the Planck measurements, we reanalyze the low redshift cosmological data to reconstruct the Hubble parameter as a function…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-18 Koushik Dutta , Ruchika , Anirban Roy , Anjan A. Sen , M. M. Sheikh-Jabbari

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

The Universe is not perfectly homogeneous, the large scale structure forms overdense regions and voids. In this paper, we consider the possibility that we occupy a special position in our Universe, close to the center of a local underdense…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-13 Viraj Nistane , Giulia Cusin , Martin Kunz

We consider the form of Hubble diagrams that would be constructed by observers in universes that are homogeneous but anisotropic, when averaged over suitably large length-scales. This is achieved by ray-tracing in different directions on…

General Relativity and Quantum Cosmology · Physics 2024-05-31 Theodore Anton , Timothy Clifton

We show that a combined analysis of CMB anisotropy power spectra obtained by the Planck satellite and luminosity distance data simultaneously excludes a flat universe and a cosmological constant at $99 \%$ CL. These results hold separately…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk

Recent detections of cosmic microwave background (CMB) anisotropy at half-degree angular scales show considerable scatter in the reported amplitude even at similar angular resolution. We use Monte Carlo techniques to simulate the current…

Astrophysics · Physics 2007-05-23 A. Kogut , G. Hinshaw

Cosmology is built on a relativistic understanding of gravity, where the geometry of the Universe is dynamically determined by matter and energy. In the cosmological concordance model, gravity is described by General Relativity, and it is…

General Relativity and Quantum Cosmology · Physics 2024-07-26 Theodore Anton

The recent analysis of low-redshift supernovae (SN) has increased the apparent tension between the value of $H_0$ estimated from low and high redshift observations such as the cosmic microwave background (CMB) radiation. At the same time…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-15 Antonio Enea Romano

The Cosmic Microwave Background (CMB) is a relict of the early universe. Its perfect 2.725K blackbody spectrum demonstrates that the universe underwent a hot, ionized early phase; its anisotropy (about 80 \mu K rms) provides strong evidence…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Paolo de Bernardis , Silvia Masi

The standard $\Lambda$CDM cosmological model informed by cosmic microwave background (CMB) anisotropies makes a precise prediction for the growth of matter density fluctuations over cosmic time on linear scales. A variety of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-14 Mathew S. Madhavacheril

The cosmic microwave background (CMB), the relic radiation from the early Universe, offers a unique window into both primordial conditions and the intervening large-scale structure (LSS) it traverses. Interactions between CMB photons and…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-24 Federico Bianchini , Abhishek S. Maniyar

The Universe on scales $10-100~h^{-1}$ Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-21 Krzysztof Bolejko , M. Ahsan Nazer , David L. Wiltshire

We present a new framework for testing the isotropy of the Universe using cosmic microwave background data, building on the nested-sampling ANICOSMO code. Uniquely, we are able to constrain the scalar, vector and tensor degrees of freedom…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-08 Daniela Saadeh , Stephen M. Feeney , Andrew Pontzen , Hiranya V. Peiris , Jason D. McEwen

In a landscape of compactifications with different numbers of macroscopic dimensions, it is possible that our universe has nucleated from a vacuum where some of our four large dimensions were compact while other, now compact, directions…

High Energy Physics - Theory · Physics 2012-01-11 Julian Adamek , David Campo , Jens C. Niemeyer

The detection of anisotropy in the cosmic microwave background on arcminute scales by the Cosmic Background Imager (CBI) provides us with our first measurement of the damping tail and closes one chapter in the CMB story. We now have…

Astrophysics · Physics 2009-08-18 Martin White

The recent measurements of the power spectrum of Cosmic Microwave Background anisotropies are consistent with the simplest inflationary scenario and big bang nucleosynthesis constraints. However, these results rely on the assumption of a…

We investigate the global texture model of structure formation in cosmogonies with non-zero cosmological constant for different values of the Hubble parameter. We find that the absence of significant acoustic peaks and little power on large…

Astrophysics · Physics 2009-10-31 Ruth Durrer , Martin Kunz , Alessandro Melchiorri