Metal-Insulator Crossover in High TC Cuprates:. Gauge Field Theory Versus Experiments

The U(1)×SU(2) Chem-Simons gauge field theory, proposed by the authors to explain in a unified fashion the metal-insulator crossover of the in-plane resistivity upon temperature decrease in heavily underdoped cuprates without magnetic field and a similar phenomenon, observed in several classes of superconducting cuprates, when a strong magnetic field suppresses the superconductivity, is briefly outlined and confronted with recent experiments.