9732963 Kamien This is a CAREER award to conduct theoretical research and to develop associated education activities. In particular, the principal investigator will study chiral molecular systems, both in the dilute limit by studying single chiral polymers, such as DNA, as well as in the semi-dilute limit where they form chiral liquid crystals. In the dilute limit a generalization of the exact mapping between self-avoiding random walks and the n-component Ising model, as n approaches zero, can be used to study chiral random walks. Just as the theory of a single self-avoiding walk can be used to study a semi-dilute melt of polymers, this extension can be used to study a semi-dilute melt of topologically linked polymers. The plan is to pursue this in connection with a number of experiments and to augment analytical theory with comparison to numerics. In the more concentrated regime, chiral polymers can form liquid crystalline phases such as the polymer cholesteric phase and the columnar hexagonal phase. Often, the chiral interactions are frustrated by the liquid crystalline packing of the molecules. Recent experiments on DNA appear to find a frustrated phase in which chirality is absent although theory suggests there is no frustration. An extensive analysis of the effect of the crystalline or liquid-crystalline order on the chiral interaction will be pursued as a possible explanation of the weaker than expected chirality in the observed phase. Integrated with the research program, a course will be developed aimed at first-year students on the subject of chiral symmetry in nature. Through both historic and scientific exposition the instructor will describe chirality as a way of introducing the idea of symmetry. Since chirality is a central notion in much of science and engineering, the course will thread through history touching on the use and discovery of chirality in different contexts. This discourse will include Pasteur's discovery of chirality, the structure of proteins and DNA as well as the discovery of parity violation in elementary particle physics. Lectures will be supplemented with simple demonstrations, such as rotation of the polarization of light in corn syrup and quartz. Finally, a discussion of left-right asymmetry in the Universe, i.e., baryon asymmetry, will be presented. %%% This is a CAREER award which integrates research and education. In this particular case, theoretical research will be conducted on the chiral molecular systems. Chirality is the property of systems in nature which distinguishes between left and right symmetry. Chiral polymers, such as DNA, will be studied as well as more concentrated solutions which form chiral liquid crystal phases. Integrated with the research program, a course will be developed aimed at first-year students on the subject of chiral symmetry in nature. Through both historic and scientific exposition the instructor will describe chirality as a way of introducing the idea of symmetry. Since chirality is a central notion in much of science and engineering, the course will thread through history touching on the use and discovery of chirality in different contexts. This discourse will include Pasteur's discovery of chirality, the structure of proteins and DNA as well as the discovery of parity violation in elementary particle physics. Lectures will be supplemented with simple demonstrations, such as rotation of the polarization of light in corn syrup and quartz. Finally, a discussion of left-right asymmetry in the Universe, i.e., baryon asymmetry, will be presented. ***
