Particles in the Early Universe

The aim of this book is to develop a contraction method for Cayley-Klein orthogonal and unitary groups (algebras), and apply it to the investigation of physical structures. Readers will find a comprehensive study summarized as follows: The space-time models (or kinematics) are described on the motion group level. The Jordan-Schwinger representations of the groups are closely connected to the properties of stationary quantum systems whose Hamiltonians are quadratic in creation and annihilation operators.The high-temperature limit of the Standard Model is associated with the contraction of its gauge group. The tending-to-zero contraction parameter is connected to the inverse average energy (temperature) of the Universe which makes it possible to re-establish the evolution of particles and their interactions in the early Universe up to Planck energy. Properties of the elementary particles change drastically in the infinite temperature limit: all particles lose mass, all quarks are monochromatic, electroweak interactions become long range and are mediated by neutral currents--