101 citations · 586 across the 25 of their papers we have counts for
26 papers
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…
Unveiling the Dynamics of Censorship, COVID-19 Regulations, and Protest: An Empirical Study of Chinese Subreddit r/china_irl
Siyi Zhou, Luca Luceri, Emilio Ferrara
The COVID-19 pandemic has intensified numerous social issues that warrant academic investigation. Although information dissemination has been extensively studied, the silenced voic…
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…
Perturbative unitarity and NEC violation in genesis cosmology
Yong Cai, Ji Xu, Shuai Zhao +1
Explorations of the violation of null energy condition (NEC) in cosmology could enrich our understanding of the very early universe and the related gravity theories. Although a ful…
Detection of Early-Universe Gravitational Wave Signatures and Fundamental Physics
Robert Caldwell, Yanou Cui, Huai-Ke Guo +34
Detection of a gravitational-wave signal of non-astrophysical origin would be a landmark discovery, potentially providing a significant clue to some of our most basic, big-picture…
Gravitational Waves from an Inflation Triggered First-Order Phase Transition
Haipeng An, Kun-Feng Lyu, Lian-Tao Wang +1
Large excursion of the inflaton field can trigger interesting dynamics. One important example is a first-order phase transition in a spectator sector which couples to the inflaton.…
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…
A unique gravitational wave signal from phase transition during inflation
Haipeng An, Kun-Feng Lyu, Lian-Tao Wang +1
We study the properties of the gravitational wave (GW) signals produced by first order phase transitions during the inflation era. We show that the power spectrum of the GW oscilla…
Cosmological Signatures of Superheavy Dark Matter
Lingfeng Li, Shiyun Lu, Yi Wang +1
We discuss two possible scenarios, namely the curvaton mechanism and the dark matter density modulation, where non-Gaussianity signals of superheavy dark matter produced by gravity…
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…
Gravitational Production of Superheavy Dark Matter and Associated Cosmological Signatures
Lingfeng Li, Tomohiro Nakama, Chon Man Sou +2
We study the gravitational production of super-Hubble-mass dark matter in the very early universe. We first review the simplest scenario where dark matter is produced mainly during…
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…
Hybrid Quasi-Single Field Inflation
Yi Wang, Yi-Peng Wu, Jun'ichi Yokoyama +1
The decay of massive particles during inflation generates characteristic signals in the squeezed limit of the primordial bispectrum. These signals are in particular distinctive in…
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…
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…
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…
Differentiating G-inflation from String Gas Cosmology using the Effective Field Theory Approach
Minxi He, Junyu Liu, Shiyun Lu +4
A characteristic signature of String Gas Cosmology is primordial power spectra for scalar and tensor modes which are almost scale-invariant but with a red tilt for scalar modes but…