101 citations · 586 across the 25 of their papers we have counts for
15 papers · 1 filter
On the importance of heavy fields in pseudo-scalar inflation
Chong-Bin Chen, Ziwei Wang, Siyi Zhou
Pseudo-scalar inflation coupled with U(1) gauge fields through the Chern-Simons term has been extensively studied. However, new physics arising from UV theories may still influence…
Spiky strings in de Sitter space
Mitsuhiro Kato, Kanji Nishii, Toshifumi Noumi +2
We study semiclassical spiky strings in de Sitter space and the corresponding Regge trajectories, generalizing the analysis in anti-de Sitter space. In particular we demonstrate th…
Perturbative unitarity in quasi-single field inflation
Suro Kim, Toshifumi Noumi, Keito Takeuchi +1
We study implications of perturbative unitarity for quasi-single field inflation with the inflaton and one massive scalar. Analyzing high energy scattering, we show that non-Gaussi…
String Regge trajectory in de Sitter space and implications for inflation
Toshifumi Noumi, Toshiaki Takeuchi, Siyi Zhou
We study the spectrum of semiclassical rotating strings in de Sitter space and its consistency. Even though a naive extrapolation of the linear Regge trajectory on flat space impli…
Heavy Spinning Particles from Signs of Primordial Non-Gaussianities: Beyond the Positivity Bounds
Suro Kim, Toshifumi Noumi, Keito Takeuchi +1
Within the so-called cosmological collider program, imprints of new particles on primordial non-Gaussianities have been studied intensively. In particular, their non-analytic featu…
Operator Method and Recursion Relations for Inflationary Correlator
Shek Kit Chu, Yi Wang, Siyi Zhou
We develop the systematics for applying operators on Minkowski correlation functions to get the inflationary correlation functions. Simple structures and recursion relations are kn…
Imprints of Schwinger Effect on Primordial Spectra
Wan Zhen Chua, Qianhang Ding, Yi Wang +1
We study the Schwinger effect during inflation and its imprints on the primordial power spectrum and bispectrum. The produced charged particles by Schwinger effect during inflation…
KLT-Like Behaviour of Inflationary Graviton Correlators
Shing Yan Li, Yi Wang, Siyi Zhou
We use the spinor helicity formalism to study KLT-like relations for the inflationary graviton four-point correlation function. New features are observed in this correlation functi…
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…
Fluctuations through a Vibrating Bounce
Robert Brandenberger, Qiuyue Liang, Rudnei O. Ramos +1
We study the evolution of cosmological perturbations in a non-singular bouncing cosmology with a bounce phase which has superimposed oscillations of the scale factor. We identify l…
Strongly Coupled Quasi-Single Field Inflation
Aditya Varna Iyer, Shi Pi, Yi Wang +2
We study the power spectrum of quasi-single field inflation where strong coupling is considered. The contribution from the massive propagator can be divided into local and non-loca…
Holographic non-Gaussianities in general single-field inflation
Hiroshi Isono, Toshifumi Noumi, Gary Shiu +2
We use holographic techniques to compute inflationary non-Gaussianities for general single-field inflation, including models with a non-trivial sound speed. In this holographic app…
On the initial condition of inflationary fluctuations
Hongliang Jiang, Yi Wang, Siyi Zhou
It is usually assumed that the inflationary fluctuations start from the Bunch-Davies (BD) vacuum and the prescription is used when interactions are calculated. We sh…
Non-Uniqueness of Classical Inflationary Trajectories on a High-Dimensional Landscape
Junyu Liu, Yi Wang, Siyi Zhou
Motivated by the string landscape, inflation may happen on a high dimensional complicated potential. We propose a new way to construct some high dimensional random potentials, and…