On the cosmological constant and the cosmic coincidence problem

According to a recently proposed idea the indirectly observed negative pressure of our present universe might be explained by the trace anomaly of quantum chromo-dynamics (QCD) as a non-perturbative effect of quantum fields in curved space-times. Examining some of the consequences of the proposed mechanism for the cosmic evolution yields no Apparent contradiction with our present picture of the universe. In conjunction with the weak anthropic principle a natural explanation of the cosmic coincidence can be provided. Further aspects such as the late-time behavior are also addressed.