Zong-Kuan Guo

Probing the coupling between dark components of the universe

We place observational constraints on a coupling between dark energy and dark matter by using 71 Type Ia supernovae (SNe Ia) from the first year of the five-year Supernova Legacy Survey (SNLS), the cosmic microwave background (CMB) shift parameter from the three-year Wilkinson Microwave Anisotropy Probe (WMAP), and the baryon acoustic oscillation (BAO) peak found in the Sloan Digital Sky Survey (SDSS). The interactions we study are (i) constant coupling

Obtaining the CMB anomalies with a bounce from the contracting phase to inflation

\ensuremath{\delta}

A TRACKER SOLUTION FOR A HOLOGRAPHIC DARK ENERGY MODEL

and (ii) varying coupling

PARAMETRIZATIONS OF THE DARK ENERGY DENSITY AND SCALAR POTENTIALS

\ensuremath{\delta}(z)

Interacting phantom energy

that depends on a redshift

Cosmological evolution of interacting phantom energy with dark matter

z

Parametrization of quintessence and its potential

, both of which have simple parametrizations of the Hubble parameter to confront with observational data. We find that the combination of the three databases marginalized over a present dark energy density gives stringent constraints on the coupling,

Cosmology with a variable Chaplygin gas

\ensuremath{-}0.08l\ensuremath{\delta}l0.03

Accelerating Cosmologies in the Einstein-Gauss-Bonnet Theory with a Dilaton

(95% C.L.) in the constant coupling model and

Inflationary attractor from tachyonic matter

\ensuremath{-}0.4l{\ensuremath{\delta}}_{0}l0.1