الفهرس 
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Abstract
We consider the evolution of a flat, isotropic and homogeneous Friedmann-Lemaitre-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, that can be character-ized by an ultra-relativistic equation of state, and bulk viscosity coefficient obtained from
recent lattice Quantum Chromodynamics calculations. The basic equation for the Hubble
parameter is derived under the assumption that the total energy in the Universe is con-served. By assuming a power law dependence of bulk viscosity coefficient, temperature and
relaxation time on energy density, an approximate solution of the field equations has been ob-tained, in which we utilized equations of state from recent lattice Quantum Chromodynamics
simulations and heavy-ion collisions to derive an evolution equation. In viscous cosmology,
there is no evidence for singularity. For example, both Hubble parameter and scale factor
have a finite value at time equal to zero. To avoid any controversial argumentation about
the validity of the equations of states and the above conclusions, we restrict the discussion at
the QCD era. Here, the evolution of essential cosmological parameters, like Hubble and scale
parameters, in a viscous background geometry is obviously modified than in non-viscous one