Phys.Rev.D, 113, 046019 (2026)
Consistent four-derivative heterotic truncations and the Kerr-Sen solution
M. Xia1, L. Ma1, Y. Pang1,2 and R. J. Saskowski1
1 Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin 300350, China.
2 Peng Huanwu Center for Fundamental Theory, Hefei, Anhui 230026, China.
* pangyi1@tju.edu.cn, robert_saskowski@tju.edu.cn
Abstract
Four-derivative heterotic supergravity (without gauge fields) reduced on a 𝑝-dimensional torus leads to half-maximal supergravity coupled to 𝑝 vector multiplets, and it is known that removing the vector multiplets is a consistent truncation of the theory. We find a new consistent truncation of four-derivative heterotic supergravity on a torus that keeps the vector multiplets and precisely reproduces the bosonic action of heterotic supergravity (with heterotic gauge fields). We show that both truncations have an 𝑂(𝑑 +𝑝,𝑑) symmetry when reduced on a 𝑑-dimensional torus and demonstrate how this embeds in the 𝑂(𝑑 +𝑝,𝑑 +𝑝) symmetry that one gets from reducing on a (𝑑+𝑝)-dimensional torus without truncation. We then use our new truncation to obtain four-derivative corrections to the Kerr-Sen solution and compute thermodynamic quantities and multipole moments. Finally, we compare the Kerr-Sen solutions of the actions corresponding to the two different choices of truncation with the Kerr solution, the Kerr-Newman solution, and each other, and show that they have distinct four-derivative multipole structures.
