  New work gathers in Chapter 6 and Chapter 7. Tthe Cardassian dynamical
equations are introduced generally and logically under GF fluid scenario,
together with the flowing process of constructing phase space and differential
dynamical systems from Friedmann equation. Hyperbolic cosecant Cardassian term
is employed for concrete computing. The analysis proceeds in two cases, namely
a unified description of matter and radiation energy density (case 1) and a
separate description of matter and radiation terms (case 2).Formalism of case 2
is more exact at the expense of more complicatedness, and due to the
mathematical symmetry of matter term and radiation term in hyperbolic cosecant
function, the differential dynamical equations are considerably simplified.
Phase space and dynamical systems for both cases are achieved. When we
calculate the critical points for case 2, amazingly interesting behaviors of
self-consistency and auto-normalization are exhibited, which is a strong
support for the new model,along with a forever positive sound speed. The
process of virial collapse in Cardassian cosmos is analyzed. Power-style
Cardassian term is employed for its simplicity.Calculation declares that virial
collapse of matter alone isforbidden. Yet Cardassian has excellent ability for
virial collapse,after the virial collapse ending up with a stable sphere, the
ratio of the ultimate radius to the original radius depends on the adjustable
parameters in Cardassian term. And, the mixture of GF fluid and matter could
conduct virial collapse, the ratio of the ultimate radius to the original
radius depends on the adjustable parameters in Cardassian term, too. No
singularity is generated.
