The Synergy between Cosmology and High Energy Physics
During the last decade we have witnessed a revolution in cosmology, primarily because of a variety of precise experimental data. Particularly important are the measurements of the temperature anisotropies of the Cosmic Microwave Background (CMB) radiation. Based on that, cosmologists constructed a standard cosmological model that is frequently referred to as the concordance model (or ΛCDM model) of big bang cosmology. It attempts to explain CMB observations, as well as large scale structure observations and supernovae observations of the accelerating expansion of the universe. It is the simplest known model that is in general agreement with observed phenomena. According to the model, the Universe is composed of only about 4% of baryonic matter (that is us), 22% of dark matter and 74% of dark energy (the component which is responsible for the observed accelerated expansion of the Universe). The Standard Model (SM) of particle physics and all accelerator experiments explains (more precisely just describes) the 4% (the baryonic matter) of the Universe. The nature of the two major constituents of our Universe, dark matter and dark energy, is so far unknown. On the top of that, it is commonly accepted that the early Universe went through a period of very fast expansion (called inflation), the mechanism responsible for the inflation is still uncertain. Vast majority of existing models of the inflation rallies on an assumption of existence of scalar particles, called inflatons, this is again an area where cosmology and fundamental interactions meet. There exists another fundamental problem of cosmology, namely the baryogenesis; is is unclear why the Universe which we know is made entirely from matter. One necessary ingredient of possible solution of this problem is breaking of CP (so called combined parity, the approximate symmetry of electroweak interactions). It is known that the SM does not provide sufficient amount of the CP violation, so again cosmology requires a modification of our theory of fundamental interactions. Summarizing, it is clear by now that the physics of fundamental interactions requires a major modification (at least it should explain the existence of 96% of matter in the Universe). This situation, in light of new cosmological (Planck satellite) accelerator (Large Hadron Collider located at CERN) experiments allows to anticipate a fascinating future for both cosmology and the high-energy physics (that is an alternative term for „particle physics” or „physics of fundamental interactions”). New data available soon (within 2-4 years) will open an exciting period both in high energy physics and in cosmology! It is conceivable that within next decade we will be able to construct the consistent theory of particle physics and cosmology.