Half-order differentials on Riemann surfaces
Half-order differentials on Riemann surfaces
复制标题
黎曼曲面上的半阶微分
DOI:
10.1137/0114073
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发表时间:
1966
期刊:
影响因子:
--
通讯作者:
M. Schiffer
中科院分区:
文献类型:
--
作者:
N. Hawley;M. Schiffer
In this paper we wish to exhibit the utility of differentials of half integer order in the theory of Riemann surfaces. We have found tha t differentials of order 89 and order 8 9 have been involved implicitly in numerous earlier investigations, e.g., Poincar~'s work on Fuchsian functions and differential equations on Riemann surfaces. But the explicit recognition of these differentials as entities to be studied for their own worth seems to be new. We believe tha t such a s tudy will have a considerable unifying effect on various aspects of the theory of Riemarm surfaces, and we wish to show, by means of examples and applications, how some parts of this theory are clarified and brought together through investigating these half-order differentials. A strong underlying reason for dealing with half-order differentials comes from the general technique of contour integration; already introduced by Riemann. In the standard theory one integrates a differential (linear) against an Abelian integral (additive function) and uses period relations and the residue theorem to arrive a t identities. As we shall demonstrate, one can do an analogous thing by multiplying two differentials of order 89 and using the same techniques of contour integration. As often happens, when one discovers a new (at least to him) enti ty and starts looking around to see where it occurs naturally, one is stunned to find so many of its hiding places a n d all so near the surface. Our current point of view concerning the s tudy of Riemann surfaces has evolved from an earlier one in which we introduced the notion of a meromorphic connection in analogy with classical notions in real differential geometry; we now view the theory of connections