1999/02/01 by Oscar Reula, Oscar A. Reula · 20 citations
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Class (philosophy) #Classical mechanics #Computer science #Cosmology and Gravitation Theories #Exponential decay #Exponential function #Exponential growth #Homogeneous #Mathematical analysis #Mathematics #Mechanics #Nonlinear system #Perfect fluid #Physics #Quantum mechanics #Relativity and Gravitational Theory #Statistical physics #gr-qc
paper · pdf · doi:10.1103/physrevd.60.083507
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 60(8) (American Physical Society)
arxiv created 1999/02/01 · openalex publication_date 1999/09/15 · arxiv updated 2016/08/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is shown that during expanding phases of flat homogeneous cosmologies all nonlinear perturbations which are small enough are bounded by an exponentially decaying function, with the exponent being a (negative) fraction of the minimum value the Hubble function takes during the expanding period considered. When the cosmological constant is negative, i.e., in our conventions, when there is sustained inflation, it follows that nonlinear perturbations which are small enough decay exponentially; thus, a cosmic no-hair theorem is established. This result holds for a large class of perfect fluid equations of state, but notably not for very ``stiff'' fluids such as the pure radiation case.