Research in theoretical physics. Annual progress report, April 1, 1981-March 31, 1982

The following results are reported: (1) phenomenological investigation of preon models. A renormalization group analysis suggests the existence of excited quarks and leptons within the range of the next generation of experiments. The feasibility of such experiments is analyzed; a search for excited leptons in e+e- annihilation at CMS energies around the mass of the Z0 is suggested; (2) the geometrical structure of unified schemes in spaces of d > 4 suggests a possible interpretation of color and flavor quantum numbers in terms of internal geometry; (3) critical fluctuations preceding a deconfining phase transition in hadron matter should be observable by measuring the high energy tail of the spectrum of direct photons in heavy ion collisions; and (4) genetic damage caused by diagnostic ultrasound was investigated. We suggest that the damage to DNA results as a consequence of its breakup due to the excitation of collective modes