In this paper we import the theory of “Calabi–Yau” algebras and categories from
symplectic topology and topological field theories, to the setting of spectra in stable
homotopy theory. Twistings in this theory will be particularly important. There will
be two types of Calabi–Yau structures in the setting of ring spectra: one that applies
to compact algebras and one that applies to smooth algebras. The main application
of twisted compact Calabi–Yau ring spectra that we will study is to describe, prove,
and explain a certain duality phenomenon in string topology. This is a duality
between the manifold string topology of Chas and Sullivan (1999) and the Lie
group string topology of Chataur and Menichi (2012). This will extend and
generalize work of Gruher (2007). Then, generalizing work of Cohen and Jones
(2017), we show how the gauge group of the principal bundle acts on this
compact Calabi–Yau structure, and we compute some explicit examples. We
then extend the notion of the Calabi–Yau structure to smooth ring spectra,
and prove that Thom ring spectra of (virtual) bundles over the loop space,
, have this structure.
In the case when
is a sphere, we will use these twisted smooth Calabi–Yau ring spectra to
study Lagrangian immersions of the sphere into its cotangent bundle.
We recast the work of Abouzaid and Kragh (2016) to show that the
topological Hochschild homology of the Thom ring spectrum induced by the
-principle
classifying map of the Lagrangian immersion detects whether that immersion can be
Lagrangian isotopic to an embedding. We then compute some examples. Finally, we
interpret these Calabi–Yau structures directly in terms of topological Hochschild
homology and cohomology.
Keywords
Hochschild homology, ring spectra, string topology,
Calabi–Yau algebras