2 papers
hep-th2025
On a -valued discrete topological term in 10d heterotic string theories
Yuji Tachikawa, Hao Y. Zhang
We show that the low-energy effective actions of two ten-dimensional supersymmetric heterotic strings are different by a -valued discrete topological term even after…
hep-th2025
Type I anomaly cancellation revisited
Saghar S. Hosseini, Yuji Tachikawa, Hao Y. Zhang
We revisit the issue of how the perturbative and global fermion anomaly of Type I string theory in ten dimensions is cancelled by the Green-Schwarz mechanism using the RR fields. T…