English
Related papers

Related papers: Cosmic crystallography: the hyperbolic isometries

200 papers

The pair separations statistical methods devised to detect the topology of the universe rely on the accurate knowledge of the three-dimensional positions of the cosmic sources. The determination of these positions, however, involves…

Astrophysics · Physics 2016-11-09 A. Bernui , G. I. Gomero , B. Mota , M. J. Reboucas

The large-scale structure in cosmology is highly non-Gaussian at late times and small length scales, making it difficult to describe analytically. Parameter inference, data reconstruction, and data generation tasks in cosmology are greatly…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-13 Adam Rouhiainen

In the literature, the matchings between spacetimes have been most of the times implicitly assumed to preserve some of the symmetries of the problem involved. But no definition for this kind of matching was given until recently. Loosely…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Raul Vera

The CMB anisotropy depends sensitively upon the slope and amplitude of primordial density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, {\it etc.} We report…

Astrophysics · Physics 2009-09-25 J. Richard Bond , Richard L. Davis , Paul J. Steinhardt

We investigate stationarity and stability of half-spaces as isoperimetric sets for product probability measures, considering the cases of coordinate and non-coordinate half-spaces. Moreover, we present several examples to which our results…

Functional Analysis · Mathematics 2011-02-18 Franck Barthe , Chiara Bianchini , Andrea Colesanti

In addition to shear and vorticity a homogeneous background may also exhibit anisotropic curvature. Here a class of spacetimes is shown to exist where the anisotropy is solely of the latter type, and the shear-free condition is supported by…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Tomi S. Koivisto , David F. Mota , Miguel Quartin , Tom G. Zlosnik

A mathematical model of the Universe evolution, based on asymmetric doublet of classical and phantom dcalar Higgs fields with a kinetic connection between the components, has been constructed and studied. A detailed qualitative analysis was…

General Relativity and Quantum Cosmology · Physics 2024-11-26 Yu. G. Ignat'ev , I. A. Kokh

Cosmology can be viewed as geodesic motion in an appropriate metric on an `augmented' target space; here we obtain these geodesics from an effective relativistic particle action. As an application, we find some exact (flat and curved)…

High Energy Physics - Theory · Physics 2016-09-06 J. G. Russo , P. K. Townsend

We examine a simple hard disc fluid with no long range interactions on the two dimensional space of constant negative Gaussian curvature, the hyperbolic plane. This geometry provides a natural mechanism by which global crystalline order is…

Soft Condensed Matter · Physics 2008-04-29 Carl D. Modes , Randall D. Kamien

A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky…

Astrophysics · Physics 2007-05-23 Carlos Hojvat , Thomas P. McCauley , Stephen Reucroft , John D. Swain

We investigate the subgroup structure of the hyperoctahedral group in six dimensions. In particular, we study the subgroups isomorphic to the icosahedral group. We classify the orthogonal crystallographic representations of the icosahedral…

Group Theory · Mathematics 2015-06-23 Emilio Zappa , Eric C. Dykeman , Reidun Twarock

Studies of disordered heterogeneous media and galaxy cosmology share a common goal: analyzing the distribution of particles at `microscales' to predict physical properties at `macroscales', whether for a liquid, composite material, or…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Oliver H. E. Philcox , Salvatore Torquato

Galactic accretion interacts in complex ways with gaseous halos, including galactic winds. As a result, observational diagnostics typically probe a range of intertwined physical phenomena. Because of this complexity, cosmological…

Astrophysics of Galaxies · Physics 2017-05-31 C. -A. Faucher-Giguere

Coordination geometries describe how the neighbours of a central particle are arranged around it. Such geometries can be thought to lie in an abstract topological space; a model of this space could provide a mathematical basis for…

Mathematical Physics · Physics 2023-06-28 John Çamkıran , Fabian Parsch , Glenn D. Hibbard

Persistent homology naturally addresses the multi-scale topological characteristics of the large-scale structure as a distribution of clusters, loops, and voids. We apply this tool to the dark matter halo catalogs from the Quijote…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-31 Jacky H. T. Yip , Matteo Biagetti , Alex Cole , Karthik Viswanathan , Gary Shiu

Computer vision tasks such as image classification, image retrieval and few-shot learning are currently dominated by Euclidean and spherical embeddings, so that the final decisions about class belongings or the degree of similarity are made…

Computer Vision and Pattern Recognition · Computer Science 2020-04-01 Valentin Khrulkov , Leyla Mirvakhabova , Evgeniya Ustinova , Ivan Oseledets , Victor Lempitsky

Direct measurements of cosmic ray (CR) species combined with observations of their associated gamma-ray emissions can be used to constrain models of CR propagation, trace the structure of the Galaxy, and search for signatures of new…

High Energy Astrophysical Phenomena · Physics 2018-04-11 Gudlaugur Johannesson , Troy A. Porter , Igor V. Moskalenko

A cosmological model with total density close to critical (and flat geometry), dominated by dark matter and dark energy of unknown nature, and consistent with the basic predictions of the inflationary scenario is a very good fit to a…

Astrophysics · Physics 2007-05-23 A. Balbi

In this paper, we introduce a new generalization of Pascal's triangle. The new object is called the hyperbolic Pascal triangle since the mathematical background goes back to regular mosaics on the hyperbolic plane. We describe precisely the…

History and Overview · Mathematics 2017-12-22 Hacene Belbachir , László Németh , László Szalay

Resent works of Hawking and Susskind suggested that information is conserved in the universe. We extend this thesis and propose that dynamics of information - computations can conserve in Anti-de-Sitter cosmological model. Information…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Vadim Astakhov
‹ Prev 1 4 5 6 7 8 10 Next ›