3.1 Problems of Big Bang Cosmology 28 a spatially flat Universe. Therefore, in the past, the value must have been even more precisely close to 1, with it having had a value of 1 to a precision of at least ∼ 10 − 62 around the Planck time. This Flatness Problem is thus a fine-tuning problem for the initial conditions of the Universe. The Flatness Problem, when looked at from a slightly different viewpoint, can also be regarded as an Age Problem. If the value of Ω had been only slightly larger than it appears to have been, then the Universe would have been of a sufficient density that it would have collapsed at a time much sooner than the age of our observable Universe. If, on the other hand, the value of Ω had been only slightly smaller than it appears to have been, then the Universe would have expanded too quickly for stars and galaxies to have formed the LSS that we observe today. Therefore, the fine-tuning problem can be regarded as an Age Problem, in that how has our observable Universe become as old as it is? In contrast to the two problems already mentioned, the Relic Problem is not specific to a Hot Big Bang model of the Universe, but rather something that has to be considered within the total picture of Particle Cosmology. There exist a large variety of particle physics models and applications of these to Cosmology that have the ability to produce many types of relic; particles and other components that contradict established theory and/or observation, such as gravitinos coming from SUGRA and moduli coming from string theory. Another example, which was the subject of the original work 3.1.3 Relic Problem