173 citations · 766 across the 17 of their papers we have counts for
17 papers
Parity Violation from Emergent Non-Locality During Inflation
Sadra Jazayeri, Sébastien Renaux-Petel, Xi Tong +2
Parity violation in the early universe holds great promise for uncovering new physics. In particular, the primordial scalar four-point correlation function is allowed to develop a…
BCS in the Sky: Signatures of Inflationary Fermion Condensation
Xi Tong, Yi Wang, Chen Zhang +1
We consider a Bardeen-Cooper-Schrieffer (BCS)-like model in the inflationary background. We show that with an axial chemical potential, the attractive quartic fermion self-interact…
Superheavy Dark Matter Production from Symmetry Restoration First-Order Phase Transition During Inflation
Haipeng An, Xi Tong, Siyi Zhou
We propose a scenario where superheavy dark matter (DM) can be produced via symmetry restoration first-order phase transition during inflation triggered by the evolution of the inf…
Termination of Superradiance from a Binary Companion
Xi Tong, Yi Wang, Hui-Yu Zhu
We study the impact of a binary companion on black hole superradiance at orbital frequencies away from the gravitational-collider-physics (GCP) resonance bands. A superradiant stat…
Large Spin-2 Signals at the Cosmological Collider
Xi Tong, Zhong-Zhi Xianyu
We study the theory and phenomenology of massive spin-2 fields during the inflation with nonzero background chemical potential, and extend the cosmological collider physics to tens…
Cutting Rule for Cosmological Collider Signals: A Bulk Evolution Perspective
Xi Tong, Yi Wang, Yuhang Zhu
We show that the evolution of interacting massive particles in the de Sitter bulk can be understood at leading order as a series of resonant decay and production events. From this…
Gravitational Collider Physics via Pulsar-Black Hole Binaries II: Fine and Hyperfine Structures are Favored
Xi Tong, Yi Wang, Hui-Yu Zhu
A rotating black hole can be clouded by light bosons via superradiance, and thus acquire an atom-like structure. If such a gravitational atom system is companioned with a pulsar, t…
Chemical-Potential-Assisted Particle Production in FRW Spacetimes
Chon Man Sou, Xi Tong, Yi Wang
We analyze gravitational particle production assisted by chemical potential. By utilizing the uniformly smoothed Stokes-line method and Borel summation, we gain insight into the fi…
A Bit Rate Bound on Superluminal Communication
Xi Tong, Yi Wang, Yuhang Zhu
We study semi-classical communication in positivity-violating k-essence scalar field theories, with superluminal modes propagating on a rolling background. The self-interactions du…
Gravitational Collider Physics via Pulsar-Black Hole Binaries
Qianhang Ding, Xi Tong, Yi Wang
We propose to use pulsar-black hole binaries as a probe of gravitational collider physics. Induced by the gravitation of the pulsar, the atomic transitions of the boson cloud aroun…
Gauge Invariance, Polar Coordinates and Inflation
Ali Akil, Xi Tong
We point out the necessity of resolving the apparent gauge dependence in the quantum corrections of cosmological observables for Higgs-like inflation models. We highlight the fact…
Probing P and CP Violations on the Cosmological Collider
Tao Liu, Xi Tong, Yi Wang +1
In direct analogy to the 4-body decay of a heavy scalar particle, the 4-point correlation function of primordial fluctuations carries P and CP information. The CP violation appears…
When Primordial Black Holes from Sound Speed Resonance Meet a Stochastic Background of Gravitational Waves
Yi-Fu Cai, Chao Chen, Xi Tong +2
As potential candidates of dark matter, primordial black holes (PBHs) are within the core scopes of various astronomical observations. In light of the explosive development of grav…
Primordial Black Holes from Sound Speed Resonance during Inflation
Yi-Fu Cai, Xi Tong, Dong-Gang Wang +1
We report on a novel phenomenon of the resonance effect of primordial density perturbations arisen from a sound speed parameter with an oscillatory behavior, which can generically…
Connections between Minkowski and Cosmological Correlation Functions
Shek Kit Chu, Mang Hei Gordon Lee, Shiyun Lu +3
We show how cosmological correlation functions of massless fields can be rewritten in terms of Minkowski correlation functions, by extracting symmetry-breaking operators from the c…
Warm Quasi-Single Field Inflation
Xi Tong, Yi Wang, Siyi Zhou
We study quasi-single field inflation with a warm inflation background. The thermal effects at small scales can sufficiently enhance the magnitude of the primordial standard clock…
On the Effective Field Theory for Quasi-Single Field Inflation
Xi Tong, Yi Wang, Siyi Zhou
We study the effective field theory (EFT) description of the virtual particle effects in quasi-single field inflation, which unifies the previous results on large mass and large mi…