Download this article
 Download this article For screen
For printing
Recent Issues
Volume 8, Issue 2
Volume 8, Issue 1
Volume 7, Issue 3
Volume 7, Issue 2
Volume 7, Issue 1
Volume 6, Issue 4
Volume 6, Issue 3
Volume 6, Issue 2
Volume 6, Issue 1
Volume 5, Issue 4
Volume 5, Issue 3
Volume 5, Issue 2
Volume 5, Issue 1
Volume 4, Issue 4
Volume 4, Issue 3
Volume 4, Issue 2
Volume 4, Issue 1
Volume 3, Issue 4
Volume 3, Issue 3
Volume 3, Issue 2
Volume 3, Issue 1
Volume 2, Issue 4
Volume 2, Issue 3
Volume 2, Issue 2
Volume 2, Issue 1
Volume 1, Issue 4
Volume 1, Issue 3
Volume 1, Issue 2
Volume 1, Issue 1
The Journal
About the journal
Ethics and policies
Peer-review process
Statement, 2023
 
Submission guidelines
Submission form
Editorial board
 
Subscriptions
 
ISSN 2576-7666 (online)
ISSN 2576-7658 (print)
Author index
To appear
 
Other MSP Journals
Twisted differential KO-theory

Daniel Grady and Hisham Sati

Vol. 8 (2026), No. 2, 265–304
Abstract

We provide a systematic approach to twisting differential KO-theory leading to a construction of the corresponding twisted differential Atiyah–Hirzebruch spectral sequence (AHSS). We relate and contrast the degree 2 and the degree 1 twists, whose description involves appropriate local systems. Along the way, we provide a complete and explicit identification of the differentials at the E2 and E3 pages in the topological case, which has been missing in the literature and which is needed for the general case. The corresponding differentials in the refined theory reveal an intricate interplay between topological and geometric data, the former involving the flat part and the latter requiring the construction of the twisted differential Pontryagin character. We illustrate with examples and applications from geometry, topology and physics. For instance, quantization conditions show how to lift differential 4k-forms to twisted differential KO-theory leading to integrality results, while considerations of anomalies in type I string theory allow for characterization of twisted differential Spin structures.

Keywords
KO-theory, twisted KO-theory, differential KO-theory, Atiyah–Hirzebruch spectral sequence, Pontryagin character, twisted differential Spin structure, type I anomaly cancellation
Mathematical Subject Classification
Primary: 19L50, 55T25
Secondary: 19L64, 55R40, 55R45
Milestones
Received: 11 November 2024
Revised: 26 May 2025
Accepted: 23 June 2025
Published: 2 April 2026
Authors
Daniel Grady
Department Of Mathematics, Statistics And Physics
Wichita State University
Wichita, KS
United States
Hisham Sati
Center for Quantum and Topological Systems (CQTS)
NYUAD Research Institute
Department of Mathematics
New York University Abu Dhabi
Abu Dhabi
United Arab Emirates
The Courant Institute for Mathematical Sciences
New York University
New York, NY
United States