3,051 research outputs found
Qualitative properties of scalar-tensor theories of Gravity
The qualitative properties of spatially homogeneous stiff perfect fluid and
minimally coupled massless scalar field models within general relativity are
discussed. Consequently, by exploiting the formal equivalence under conformal
transformations and field redefinitions of certain classes of theories of
gravity, the asymptotic properties of spatially homogeneous models in a class
of scalar-tensor theories of gravity that includes the Brans-Dicke theory can
be determined. For example, exact solutions are presented, which are analogues
of the general relativistic Jacobs stiff perfect fluid solutions and vacuum
plane wave solutions, which act as past and future attractors in the class of
spatially homogeneous models in Brans-Dicke theory.Comment: 19 page
Fast-slow asymptotics for a Markov chain model of fast sodium current
We explore the feasibility of using fast-slow asymptotic to eliminate the
computational stiffness of the discrete-state, continuous-time deterministic
Markov chain models of ionic channels underlying cardiac excitability. We focus
on a Markov chain model of the fast sodium current, and investigate its
asymptotic behaviour with respect to small parameters identified in different
ways.Comment: 16 pages, 6 figures, as accepted to Chaos 2017/09/0
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