3 papers
hep-th2026
Loop integrals in de Sitter spacetime: The parity-split IBP system and -form differential equations
Jiaqi Chen, Bo Feng, Zhehan Qin +1
We develop integration-by-parts (IBP) reduction and differential equations for massive loop integrals of cosmological correlators in de Sitter (dS) spacetime, demonstrating the fea…
hep-th2025
Open Effective Field Theory and the Physics of Cosmological Collider Signals
Thomas Colas, Zhehan Qin, Xi Tong
We examine the origin of the cosmological collider signal using the framework of open effective field theories. Focusing on the single exchange of a massive scalar field, we demons…
hep-th2025
as an Effective Theory in de Sitter
Sebastian Cespedes, Zhehan Qin, Dong-Gang Wang
Effective field theories (EFTs) provide a powerful framework to parametrise unknown aspects of possible ultraviolet (UV) physics. For scalar fields in de Sitter space, however, new…