63 citations · 200 across the 13 of their papers we have counts for
13 papers
Cosmological Collider Signals From a Triangle Loop
Zhehan Qin, Zhong-Zhi Xianyu
Triangular loop signals appear frequently in cosmological collider models but their analytical forms remain unknown due to multiple technical challenges. Here, we determine for the…
On-Shell Bootstrap of Loop Inflation Correlators with Spectral Dispersion
Haoyuan Liu, Zhehan Qin, Jiayi Wu +2
We develop a new bootstrap strategy for cosmological correlators at loop level, which we call spectral dispersion. It is based on two conceptual observations that a correlator can…
Fermionic Bubble Loop in Cosmological Collider Revisited: Exact signals from spectral and Mellin-Barnes methods
Shuntaro Aoki, Zhehan Qin, Masahide Yamaguchi +1
Fermionic degrees of freedom are essential ingredients in cosmological collider physics and are well motivated by many phenomenological models beyond the Standard Model, but their…
The Exact and Approximate Tales of Boost-Breaking Cosmological Correlators
Zhehan Qin, Sébastien Renaux-Petel, Xi Tong +2
Cosmological correlators offer a remarkable window into the high-energy physics governing Universe's earliest moments, with the tantalising prospect of discovering new particles. H…
Primordial Stochastic Gravitational Waves from Massive Higher-Spin Bosons
Haipeng An, Zhehan Qin, Zhong-Zhi Xianyu +1
Can a stationary stone radiate gravitational waves (GWs)? While the answer is typically "no" in flat spacetime, we get a "yes" in inflationary spacetime. In this work, we study the…
Cosmological Correlators at the Loop Level
Zhehan Qin
Cosmological correlators encode rich information about physics at the Hubble scale and may exhibit characteristic oscillatory signals due to the exchange of massive particles. Alth…
Dispersive Bootstrap of Massive Inflation Correlators
Haoyuan Liu, Zhehan Qin, Zhong-Zhi Xianyu
Inflation correlators with massive exchanges are central observables of cosmological collider physics, and are also important theoretical data for us to better understand quantum f…
Nonanalyticity and On-Shell Factorization of Inflation Correlators at All Loop Orders
Zhehan Qin, Zhong-Zhi Xianyu
The dynamics of quantum fields during cosmic inflation can be probed via their late-time boundary correlators. The analytic structure of these boundary correlators contains rich ph…
Inflation Correlators at the One-Loop Order: Nonanalyticity, Factorization, Cutting Rule, and OPE
Zhehan Qin, Zhong-Zhi Xianyu
Inflation correlators with one-loop massive exchange encode rich information about the dynamics of the massive loop particles. Their nonanalytic behavior in certain soft limits lea…
Closed-Form Formulae for Inflation Correlators
Zhehan Qin, Zhong-Zhi Xianyu
We derive exact and closed-form expressions for a large class of two-point and three-point inflation correlators with the tree-level exchange of a single massive particle. The inte…
Helical Inflation Correlators: Partial Mellin-Barnes and Bootstrap Equations
Zhehan Qin, Zhong-Zhi Xianyu
Massive spinning particles acquire helicity-dependent chemical potentials during the inflation from axion-type couplings. Such spinning fields can mediate sizable inflaton correlat…
Phase Information in Cosmological Collider Signals
Zhehan Qin, Zhong-Zhi Xianyu
Massive particles produced during the cosmic inflation can imprint in the primordial non-Gaussianities as characteristic oscillating functions of various momentum ratios, known as…
Fracton Topological Order at Finite Temperature
Xiaoyang Shen, Zhengzhi Wu, Linhao Li +2
As new kinds of stabilizer code models, fracton models have been promising in realizing quantum memory or quantum hard drives. However, it has been shown that the fracton topologic…