Problems with the current cosmological paradigm

We note that despite the apparent support for the ACDM model from the acoustic peaks of the CMB power spectrum and the SNIa Hubble diagram, the standard cosmological model continues to face several fundamental problems. First, the model continues to depend wholly on two pieces of undiscovered physics, namely dark energy and cold dark matter. Then, the implied dark energy density is so small that it is unstable to quantum correction and its size is fine-tuned to the almost impossible level of one part in approximate to 10(102); it is also difficult to explain the coincidence between the dark energy, dark matter and baryon densities at the present day. Moreover, any model with a positive A also creates fundamental difficulties for superstring theories of quantum gravity. We also review the significant number of astrophysical observations which are now in contradiction with the ACDM model. On the grounds that the SNIa Hubble diagram is prone to evolutionary corrections and also that the CMB power spectrum may be contaminated by the effects of foreground ionised gas, we argue that the existence of such systematics could still allow more satisfactory, alternative, models to appear. We suggest that if H-0 less than or similar to 50kms(-1)Mpc(-1) then a simpler, inflationary model with Omega(baryon) = 1 might be allowed with no need for dark energy or cold dark matter. We note that the clear scale error between HST Cepheid and Tully-Fisher galaxy distances and also potential metallicity dependencies for both the Cepheid P-L relation and the SNIa Hubble diagram may mean that such a low value of H-0 cannot yet be ruled out.