In [GH09] M. Goresky and N. Hingston described and investigated various properties of a product on the cohomology of the free loop space of a closed, oriented manifold M relative to the constant loops. In this thesis we will give Morse and Floer theoretic descriptions of the product. There is a theorem due to J. Jones in [JJ87] which describes an isomorphism between cohomology of the free loop space and Hochschild homology of the singular cochain algebra of M with rational coefficients. We will use the theorem of J. Jones to find an algebraic model for the Goresky-Hingston product. We then use the algebraic model to explore further properties and applications of the Goresky Hingston product. In particular we use it to compute the ring structure for the n-spheres.

In [GH09] M. Goresky and N. Hingston described and investigated various properties of a product on the cohomology of the free loop space of a closed, oriented manifold M relative to the constant loops. In this thesis we will give Morse and Floer theoretic descriptions of the product. There is a theorem due to J. Jones in [JJ87] which describes an isomorphism between cohomology of the free loop space and Hochschild homology of the singular cochain algebra of M with rational coefficients. We will use the theorem of J. Jones to find an algebraic model for the Goresky-Hingston product. We then use the algebraic model to explore further properties and applications of the Goresky Hingston product. In particular we use it to compute the ring structure for the n-spheres.

<p dir="ltr">We develop a cyclic theory for categorical coalgebras and show that, when applied to the categorical coalgebra of singular chains on a space, this provides an algebraic model for its free loop space as an S¹-space. In other words, the natural circle action on loop spaces, given by rotation of loops, is encoded in the algebraic structure. In particular, the cyclic homology of the categorical coalgebra of singular chains on a topological space X is isomorphic to the S¹-equivariant homology of the free loop space. This extends known results relating cyclic theories for the algebra of chains on the based loop space and the equivariant homology of its free loop space. In fact, our statements do not require X to be simply connected, and we work over an arbitrary commutative ring. Along the way, we introduce a family of polytopes, coined as Goodwillie polytopes, that control the combinatorics behind the relationship of the coHochschild complex of a categorical coalgebra and the Hochschild complex of its associated differential graded category.</p>