63 citations · 190 across the 13 of their papers we have counts for
15 papers
Exact Solutions for Chiral Gravitational Waves from Spin-2 Mixing
Mohammad Ali Gorji, Yuhang Zhu
A spectator spin-2 field can mix linearly with the metric tensor perturbations. We study the coupled tensor system in an inflationary background, including a parity violating effec…
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…
Natura Non Facit Saltum: An Analytical Model of Smooth Slow-Roll to Ultra-Slow-Roll Transition
Diego Cruces, Minxi He, Shi Pi +3
In this letter, we propose a single-field inflation model that realizes a slow-roll-to-ultra-slow-roll transition while keeping the second slow-roll parameter smoothly varying thro…
Every Wrinkle Carries A Memory: An Integro-differential Bootstrap for Features in Cosmological Correlators
Sadra Jazayeri, Xi Tong, Yuhang Zhu
Motivated by cosmological observations, we push the cosmological bootstrap program beyond the de Sitter invariance lamppost by considering correlators that explicitly break scale i…
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…
A Match Made in Heaven: Linking Observables in Inflationary Cosmology
David Stefanyszyn, Xi Tong, Yuhang Zhu
Cosmological correlation functions of inflaton and graviton perturbations are the fundamental observables of early universe cosmology and remain a primary target for observations.…
Cosmological Correlators with Double Massive Exchanges: Bootstrap Equation and Phenomenology
Shuntaro Aoki, Lucas Pinol, Fumiya Sano +2
Using the recently developed cosmological bootstrap method, we compute the exact analytical solution for the seed integral appearing in cosmological correlators with double massive…
Cosmological Correlators Through the Looking Glass: Reality, Parity, and Factorisation
David Stefanyszyn, Xi Tong, Yuhang Zhu
We consider the evolution of quantum fields during inflation, and show that the total-energy singularities appearing in the perturbative expansion of the late-time Wavefunction of…
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…
Numerical prescriptions of early-time divergences of the in-in formalism
Duc Huy Tran, Yi Wang, Juanyi Yang +1
In quantum field theory, the in and out states can be related to the full Hamiltonian by the prescription. A Wick rotation can further bring the correlation functions to Eucli…
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…
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…
Non-Standard Primordial Clocks from Dynamical Mass in Alternative to Inflation Scenarios
Yi Wang, Zun Wang, Yuhang Zhu
In the primordial universe, oscillations of heavy fields can be considered as standard clocks to measure the expansion or contraction history of the universe. Those standard clocks…
Cosmological Collider Signatures of Massive Vectors from Non-Gaussian Gravitational Waves
Yi Wang, Yuhang Zhu
The cosmological collider provides a model-independent probe of particle physics during inflation. We extend the study of cosmological collider physics to much smaller scales throu…