Dice Question Streamline Icon: https://streamlinehq.com

Spectrum-level identification of R^sfr with the delooped J-homomorphism fiber

Establish a homotopy equivalence of ring spectra R^sfr ≃ Σ^∞ hofib(BJ), where BJ denotes the 1-fold delooping of the real J-homomorphism.

Information Square Streamline Icon: https://streamlinehq.com

Background

The construction of the parameterized Lagrangian Floer homotopy type yields an endomorphism ring spectrum Rsfr governing spherically framed flow categories. The authors anticipate that Rsfr encodes spherically framed bordism and is closely tied to the real J-homomorphism.

Identifying Rsfr with the suspension spectrum of the homotopy fiber of BJ would provide a conceptual and computational bridge between Floer homotopy structures and classical stable homotopy via the J-homomorphism, clarifying the intrinsic tangential structure underlying spherically framed flow categories.

References

Conjecture There is a homotopy equivalence of ring spectra \begin{equation} Rsfr\simeq\Sigma\infty\mathrm{hofib}BJ, \end{equation} BJ is the 1-fold delooping of the $J$-homomorphism.

Parameterized Lagrangian Floer homotopy (2506.20122 - Blakey et al., 25 Jun 2025) in Appendix: Spherically framed versus framed bordism