English
Related papers

Related papers: Symmetric hyperbolic systems for Bianchi equations

200 papers

In this paper we show that the spatially homogeneous Bianchi type I and Kantowski-Sachs cosmologies derived from the Brans-Dicke theory of gravity admit a supersymmetric extension at the quantum level. Global symmetries in the effective…

General Relativity and Quantum Cosmology · Physics 2009-10-31 James E. Lidsey , P. Vargas Moniz

We provide a simple, combinatorial criteria for a hierarchically hyperbolic space to be relatively hyperbolic by proving a new formulation of relative hyperbolicity in terms of hierarchy structures. In the case of clean hierarchically…

Geometric Topology · Mathematics 2020-07-16 Jacob Russell

A new class of a spatially homogeneous and anisotropic Bianchi type-I cosmological models of the universe for perfect fluid distribution within the framework of scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett.…

General Physics · Physics 2012-11-15 Anirudh Pradhan , Ajay Kumar Singh , H. Amirhashchi

We prove, under a certain representation theoretic assumption, that the set of real symmetric matrices, whose eigenvalues satisfy a linear matrix inequality, is itself a spectrahedron. The main application is that derivative relaxations of…

Algebraic Geometry · Mathematics 2022-10-04 Mario Kummer

A large class of explicit hyperbolic monopole solutions can be obtained from JNR instanton data, if the curvature of hyperbolic space is suitably tuned. Here we provide explicit formulae for both the monopole spectral curve and its rational…

High Energy Physics - Theory · Physics 2015-06-19 Stefano Bolognesi , Alex Cockburn , Paul Sutcliffe

Causal properties of Lorentzian symmetric spaces are investigated in the paper. The global hyperbolicity of the Cahen--Wallach Lorentzian symmetric spaces is proved.

Differential Geometry · Mathematics 2010-12-09 Ya. V. Bazaikin

We present the general properties of dynamic dissipative fluid distribution endowed with hyperbolical symmetry. All the equations required for its analysis are exhibited and used to contrast the behavior of the system with the spherically…

General Relativity and Quantum Cosmology · Physics 2022-10-05 L. Herrera

In this note we present a method for constructing CMC-1 surfaces in hyperbolic 3-space $\bfH^3(-1)$ in terms of holomorphic data first introduced in Bianchi's Lezioni di Geometria Differenziale of 1927, therefore predating by many years the…

Differential Geometry · Mathematics 2007-05-23 Levi Lopes de Lima , Pedro Roitman

Bianchi type V bulk viscous fluid cosmological models are investigated. Using a generation technique (Camci {\it et al.}, 2001), it is shown that the Einstein's field equations are solvable for any arbitrary cosmic scale function. The…

General Relativity and Quantum Cosmology · Physics 2009-07-23 Anirudh Pradhan , Vandana Rai , R. S. Singh

We prove that the hyperbolicity cones of elementary symmetric polynomials are spectrahedral, i.e., they are slices of the cone of positive semidefinite matrices. The proof uses the matrix--tree theorem, an idea already present in Choe et…

Optimization and Control · Mathematics 2013-09-23 Petter Brändén

Using the framework of Colombeau algebras of generalized functions, we prove the existence and uniqueness results for global generalized solvability of semilinear hyperbolic systems with nonlinear nonlocal boundary conditions. We admit…

Analysis of PDEs · Mathematics 2025-12-10 Irina Kmit

Hyperbolic formulations of the equations of motion are essential technique for proving the well-posedness of the Cauchy problem of a system, and are also helpful for implementing stable long time evolution in numerical applications. We,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Gen Yoneda , Hisa-aki Shinkai

We prove the existence of normally hyperbolic invariant cylinders in nearly integrable hamiltonian systems.

Dynamical Systems · Mathematics 2015-05-14 Patrick Bernard

All hypersurface homogeneous locally rotationally symmetric spacetimes which admit conformal symmetries are determined and the symmetry vectors are given explicitly. It is shown that these spacetimes must be considered in two sets. One set…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Pantelis S. Apostolopoulos , Michael Tsamparlis

The relativistic membrane equation can be rewritten as a first order hyperbolic system. Making use of the characteristic decomposition method, a new blow-up theorem is established. As an application, it demonstrates the formation of…

Analysis of PDEs · Mathematics 2025-08-12 Lv Cai , Jianli Liu

We give a solution to Dehn's isomorphism problem for the class of all hyperbolic groups, possibly with torsion. We also prove a relative version for groups with peripheral structures. As a corollary, we give a uniform solution to…

Group Theory · Mathematics 2021-04-02 François Dahmani , Vincent Guirardel

We study a class of two dimensional partially hyperbolic systems, not necessarily skew products, trying to establish the germ of a general theory. To illustrate the scope of the theory, we apply our results to the case of fast-slow…

Dynamical Systems · Mathematics 2022-02-23 Roberto Castorrini , Carlangelo Liverani

Einstein's field equations for stationary Bianchi type II models with a perfect fluid source are investigated. The field equations are rewritten as a system of autonomous first order differential equations. Dimensionless variables are…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Ulf S. Nilsson , C. Uggla

We construct perfect fluid metrics corresponding to spacelike surfaces invariant under a 1-dimensional group of isometries in 3-dimensional Minkowski space. Under additional assumptions we obtain new cosmological solutions of Bianchi type…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Adam Szereszewski , Jacek Tafel

We show under the assumption of small data that solutions to the Einstein-Vlasov system with a pure magnetic field and Bianchi I symmetry isotropise and tend to dust solutions. We also obtain the decay rates for the main variables. This…

General Relativity and Quantum Cosmology · Physics 2024-06-18 Ho Lee , Ernesto Nungesser