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Related papers: Constraining topology in harmonic space

200 papers

We reexamine the possibility of the detection of the cosmic topology in nearly flat hyperbolic Friedmann-Lemaitre-Robertson-Walker (FLRW) universes by using patterns repetition. We update and extend our recent results in two important ways:…

General Relativity and Quantum Cosmology · Physics 2009-11-07 G. I. Gomero , M. J. Reboucas , R. Tavakol

We study a multipole vector-based decomposition of cosmic microwave background (CMB) data in order to search for signatures of a multiconnected topology of the universe. Using 10^6 simulated maps, we analyse the multipole vector…

Astrophysics · Physics 2015-05-13 P. Bielewicz , A. Riazuelo

We perform a cosmographic analysis using several cosmological observables such as the luminosity distance moduli, the volume distance, the angular diameter distance and the Hubble parameter. These quantities are determined using different…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Jun-Qing Xia , Vincenzo Vitagliano , Stefano Liberati , Matteo Viel

Deviations from statistical isotropy can be modeled in various ways, for instance, anisotropic cosmological models (Bianchi models), compact topologies and presence of primordial magnetic field. Signature of anisotropy manifests itself in…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Nidhi Joshi , Sanjay Jhingan , Tarun Souradeep , Amir Hajian

The standard cosmological model, which assumes statistical isotropy and parity invariance, predicts the absence of correlations between even-parity and odd-parity observables of the cosmic microwave background (CMB). Contrary to these…

We discuss ability of the harmonic pattern of peaks in the CMB angular power spectrum to test inflation. By studying robust features of alternate models, which must all be isocurvature in nature, we reveal signatures unique to inflation.…

Astrophysics · Physics 2007-05-23 Martin White , Wayne Hu

A nontrivial topology of the spatial section of the universe is an observable, which can be probed for all locally homogeneous and isotropic universes, without any assumption on the cosmological density parameters. We discuss how one can…

Astrophysics · Physics 2008-11-26 M. J. Reboucas

We study independent and identically distributed random iterations of continuous maps defined on a connected closed subset $S$ of the Euclidean space $\mathbb{R}^{k}$. We assume the maps are monotone (with respect to a suitable partial…

Dynamical Systems · Mathematics 2020-05-28 Edgar Matias , Eduardo Silva

We give new lower bounds for the (higher) topological complexity of a space, in terms of the Lusternik-Schnirelmann category of a certain auxiliary space. We also give new lower bounds for the rational topological complexity of a space, and…

Algebraic Topology · Mathematics 2016-01-20 Mark Grant , Gregory Lupton , John Oprea

The Cosmological Principle states that the universe is both homogeneous and isotropic. This, alone, is not enough to specify the global geometry of the spacetime. If we were able to measure both the Hubble constant and the energy density we…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Edward Malec , Niall Ó Murchadha

We reexamine constraints on the spatial size of closed toroidal models with cold dark matter and the cosmological constant from cosmic microwave background. We carry out Bayesian analyses using the Cosmic Background Explorer (COBE) data…

Astrophysics · Physics 2009-11-07 Kaiki Taro Inoue , Naoshi Sugiyama

CMB anisotropy measurements have brought the issue of global topology of the universe from the realm of theoretical possibility to within the grasp of observations. The global topology of the universe modifies the correlation properties of…

Astrophysics · Physics 2009-10-31 J. Richard Bond , Dmitry Pogosyan , Tarun Souradeep

We suggest that the solution to the cosmological vacuum energy puzzle does not require any new field beyond the standard model, but rather can be explained as a result of the interaction of the infrared sector of the effective theory of…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-13 Federico R. Urban , Ariel R. Zhitnitsky

A great deal of experimental effort is currently being devoted to the precise measurements of the cosmic microwave background (CMB) sky in temperature and polarisation. Satellites, balloon-borne, and ground-based experiments scrutinize the…

Even when completely and consistently formulated, a fundamental theory of physics and cosmological boundary conditions may not give unambiguous and unique predictions for the universe we observe; indeed inflation, string/M theory, and…

High Energy Physics - Theory · Physics 2009-10-07 Anthony Aguirre , Max Tegmark

We use a complete and rigorous statistical indicator to measure the level of concordance between cosmological data sets, without relying on the inspection of the marginal posterior distribution of some selected parameters. We apply this…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-24 Marco Raveri

We prove that a quasiisometric map between rank one symmetric spaces is within bounded distance from a unique harmonic map. In particular, this completes the proof of the Schoen-Li-Wang conjecture.

Differential Geometry · Mathematics 2015-08-27 Yves Benoist , Dominique Hulin

In this paper we investigate the space of harmonic maps from a 2-torus to $\mathbb{S}^3$ using the spectral curve correspondence and Whitham deformations. In an open and dense subset of a parameter space we find that the space of harmonic…

Differential Geometry · Mathematics 2019-07-26 Emma Carberry , Ross Ogilvie

This article studies the harmonicity of vector fields on Riemannian manifolds, viewed as maps into the tangent bundle equipped with a family of Riemannian metrics. Geometric and topological rigidity conditions are obtained, especially for…

Differential Geometry · Mathematics 2008-09-17 M. Benyounes , E. Loubeau , L. Todjihounde

The predictions of mean-field electrodynamics can now be probed using direct numerical simulations of random flows and magnetic fields. When modelling astrophysical MHD, it is important to verify that such simulations are in agreement with…

Data Analysis, Statistics and Probability · Physics 2018-09-12 Irina Makarenko , Paul Bushby , Andrew Fletcher , Robin Henderson , Nikolay Makarenko , Anvar Shukurov