Zobrazeno 1 - 10
of 25
pro vyhledávání: '"Billyard, Andrew P."'
Autor:
Billyard, Andrew P., Sajko, William N.
Publikováno v:
Gen.Rel.Grav. 33 (2001) 1929-1952
We examine generalizations of the five-dimensional canonical metric by including a dependence of the extra coordinate in the four-dimensional metric. We discuss a more appropriate way to interpret the four-dimensional energy-momentum tensor induced f
Externí odkaz:
http://arxiv.org/abs/gr-qc/0105074
Publikováno v:
J.Math.Phys. 41 (2000) 6277-6283
We study early universe cosmologies derived from a scalar-tensor action containing cosmological constant terms and massless fields. The governing equations can be written as a dynamical system which contains no past or future asymptotic equilibrium s
Externí odkaz:
http://arxiv.org/abs/gr-qc/0005118
Publikováno v:
Class.Quant.Grav. 17 (2000) 453-484
A complete qualitative study of the dynamics of string cosmologies is presented for the class of isotopic curvature universes. These models are of Bianchi types I, V and IX and reduce to the general class of Friedmann-Robertson-Walker universes in th
Externí odkaz:
http://arxiv.org/abs/hep-th/9911086
Autor:
Billyard, Andrew P.
The asymptotic behaviour of two classes of scalar field cosmological models are studied using the theory of dynamical systems: general relativistic Bianchi models containing matter and a scalar field with an exponential potential and a class of spati
Externí odkaz:
http://arxiv.org/abs/gr-qc/9908067
Autor:
Billyard, Andrew P., Coley, Alan A.
Publikováno v:
Phys.Rev.D61:083503,2000
We investigate spatially flat isotropic cosmological models which contain a scalar field with an exponential potential and a perfect fluid with a linear equation of state. We include an interaction term, through which the energy of the scalar field i
Externí odkaz:
http://arxiv.org/abs/astro-ph/9908224
Publikováno v:
Phys.Rev. D61 (2000) 043504
A complete global analysis of spatially-flat, four-dimensional cosmologies derived from the type IIA string and M-theory effective actions is presented. A non--trivial Ramond-Ramond sector is included. The governing equations are written as a dynamic
Externí odkaz:
http://arxiv.org/abs/hep-th/9908102
Publikováno v:
J.Math.Phys. 40 (1999) 5092
A qualitative analysis is presented for a class of homogeneous cosmologies derived from the string effective action when a cosmological constant is present in the matter sector of the theory. Such a term has significant effects on the qualitative dyn
Externí odkaz:
http://arxiv.org/abs/gr-qc/9907043
Publikováno v:
Phys.Rev. D59 (1999) 123505
A qualitative analysis is presented for spatially flat, isotropic and homogeneous cosmologies derived from the string effective action when the combined effects of a dilaton, modulus, two-form potential and central charge deficit are included. The la
Externí odkaz:
http://arxiv.org/abs/gr-qc/9903095
Publikováno v:
Phys.Rev. D59 (1999) 023507
We study the qualitative properties of cosmological models in scalar-tensor theories of gravity by exploiting the formal equivalence of these theories with general relativity minimally coupled to a scalar field under a conformal transformation and fi
Externí odkaz:
http://arxiv.org/abs/gr-qc/9807055
Autor:
Billyard, Andrew, Gladman, Brad
Publikováno v:
Military Operations Research; 2023, Vol. 28 Issue 4, p57-71, 15p
