A number of interrelated areas of low temperature physics are brought together in this volume. The four topics are presented as separate chapters. First is the study of the Kibble-Zurek mechanism for defect formation following quench cooling of superfluid 3He and its relation to quantum field theory. Properties of heavy fermion materials are described next with special attention to the competition between magnetism and superconductivity. Some of the newest correlated electron systems are discussed and the arguments for possible unconventional nature of the superconducting order parameter are presented for these systems, including the novel coexistence of ferromagnetism and superconductivity. Highly polarized degenerate Fermi liquids are of substantial interest in many areas of physics. The most complete description of observations of thermodynamic and transport phenomena are reviewed here for the case of polarized liquid 3He obtained by rapid melting from a polarized solid and subsequent rapid refrigeration. Properties of the melting curve of 3He, and the related technique of melting curve thermometry are described in detail. Superfluid 3He and Quantum Field Theory Large Scale structure of the Universe Unconventional Superconductivity Heavy Fermions Quantum Phase Transitions Polarized Fermi Liquids Rapid Melting 3He Melting Curve Low Temperature Thermometry.