Cosmic inventory of energy densities: issues and concerns

The dynamics of our universe is characterised by the density parameters for cosmological constant (${\mathrm{\Omega }}_V$), nonbaryonic darkmatter($\Omega_{\rm wimp}$),radiation($\Omega_R$)andbaryons($\Omega_B$). To these parameters – which describe the smooth background universe – one needs to add at least another dimensionless number ($\sim {10}^{-5}$) characterising the strength of primordial fluctuations in the gravitational potential, in order to ensure formation of structures by gravitational instability. I discuss several issues related to the description of the universe in terms of these numbers and argue that we do not yet have a fundamental understanding of these issues.