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Loop calculations of superstring theory and string field theory

超弦理论和弦场论的循环计算

基本信息

批准号：
02640212
负责人：
EZAWA Zyuniti
金额：
$ 1.47万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

(1)Ezawa analyzed the superstring theory perturbatively by using covariantized Feynman-like rules known in the time of the dual resonance model. For this purpose, a new scheme was proposed to insert a certain projector into a propagator to take into account the so-called picture-changing operator. Based on the method the problem of finiteness of the superstring theory was discussed.(2)Ezawa also analyzed the theory of anyons. Anyons are particles having fractional statistics peculiar to two-dimensional space. First, various properties of topological excitations (vortices) are studied in the anyon system. Then, constructing a field theory of anyons, a new method of analyzing the quantum Hall state in the planar electron system was proposed. By applying the scheme to a double-layer electron system, it was found that the Josephson effect should be observed at a certain Landau-level filling fraction. This implies a possibility of obtaining a new type of superconductivity in a system made of semiconductors. Furthermore, the observation of the Josephson effect turns out to determine the charge of the condensate of the quantum Hall state, which is claimed to be the elementary charge e.(3)Yoshimura analyzed the two-demensional gravity as a prototype. The proposed model can be quantized semiclassically, and furthermore it can be solved explicitly. Using the solutions a concrete picture of a gravitational collapes is obtained.(4)Superstring theory leads to certain supergravity or grand unified theories. Okada analyzed the quantum correction made on the Higgs mass through loop corrections due to top quarks and their superpartners in such a theory. A possibility of observing Higgs particles in near-future experiments was also discussed.

(1)Ezawa利用在对偶共振模型中已知的协变的类Feynman规则对超弦理论进行了微扰分析。为此，提出了一种新的方案，将某个投影仪插入到传播器中，以考虑所谓的图像切换算子。在此基础上，讨论了超弦理论的有限性问题。(2)Ezawa还分析了任意子理论。任意子是具有二维空间特有的分数统计的粒子。首先，研究了任意子系统中拓扑激发(涡旋)的各种性质。然后，通过构造任意子场论，提出了一种分析平面电子系统量子霍尔态的新方法。通过将该方案应用于一个双层电子系统，发现在一定的朗道能级填充分数处应该观察到约瑟夫森效应。这意味着在由半导体组成的系统中获得一种新型超导电性的可能性。此外，对约瑟夫森效应的观测还确定了量子霍尔态凝聚体的电荷，这被认为是基本电荷e。(3)吉村以二维引力为原型进行了分析。该模型可以半经典量子化，并且可以显式求解。利用这些解，得到了引力崩塌的具体图像。(4)超弦理论导致了某些超引力理论或大统一理论。冈田分析了在这样的理论中，由于顶夸克及其超伙伴，通过回路修正对希格斯质量进行的量子修正。还讨论了在不久的将来的实验中观测希格斯粒子的可能性。