Cohomology operations from S¹-cobordisms in Floer homology
Cohomology operations from S¹-cobordisms in Floer homology
复制标题
弗洛尔同调中 S1-配边的上同调运算
DOI:
10.3929/ethz-a-001475365
复制
发表时间:
1995
影响因子:
1.8
通讯作者:
M. Schwarz
中科院分区:
文献类型:
--
作者:
M. Schwarz
In this work, Floer homology is considered as a relative Morse theory for the symplectic action functional on the loop space of a symplectic manifold (M, to). It is assumed that M is closed and the cohomology classes {w},ci(TM) H2{M) vanish on ^(M). In Floer homology the relative gradient flow for the Hamiltonian action functional is analysed by means of a class of nonlinear Fredholm operators for maps of the infinite standard cylinder 1x5' into M. The operators involved are elliptic partial differential operators of Cauchy-Riemann type. The boundary conditions are given by contractible non-degenerate 1periodic solutions of a fixed Hamiltonian equation. It is shown that the analytical concept of Floer homology for these nonlin¬ ear Cauchy-Riemann operators can be generalized from the standard cylinder to arbitrary Riemann surfaces which are either closed or have ends which are endowed with the standard cylindrical structure and carry a specified orien¬ tation. A nonlinear Fredholm analysis is used to define algebraic operations on the Floer homology groups. In our work the equivalent description as a cohomology theory is chosen. Under the specified conditions these groups are known to be canonically isomorphic to the singular homology of M as a graded Z2-vector space. The cohomological operations associated to Riemann surfaces give rise to further algebraic structures on this graded vector space. The main result is that the Floer cohomology HF*{M,1j2) carries the struc¬ ture of a Z-graded associative and commutative algebra over Z2 with unit and with a non-degenerate symmetric bilinear form. The operation Z(Ti) on Floer cohomology associated to a Riemann surface S is defined by counting solutions of nonlinear Cauchy-Riemann type partial differential equations under generic conditions. It is proven that the operator Z(E) is uniquely determined by the topological type of the model surface S, that is, the oriented homeomorphisms class of the compactified surface. Here, the oriented cylindrical ends are compactified as (0,1] x S1 and [— 1,0) x S1, re¬ spectively. Thus, every such surface can be viewed as an oriented 51-cobordism. It turns out that our theory leads to a functor Z which assigns to each such cobordism S with a + b ends of specified orientation a multi-linear operator Z{T,): ®hHF*. It is proven that this functor Z satisfies the ax¬ ioms of a topological field theory in dimension 1 + 1 in the sense of Atiyah, [3]. This is equivalent to describing the vector space HF* as an algebra over Z2 with unit and non-degenerate bilinear form compatible with the multiplication.