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Related papers: Cosmological Correlators at the Loop Level

200 papers

The space of inflationary models is vast, containing wide varieties of mechanisms, symmetries, and spectra of particles. Consequently, the space of observational signatures is similarly complex. Hence, it is natural to look for boundaries…

High Energy Physics - Theory · Physics 2020-10-29 Daniel Green , Enrico Pajer

We extend the cosmological bootstrap to correlators involving massless particles with spin. In de Sitter space, these correlators are constrained both by symmetries and by locality. In particular, the de Sitter isometries become conformal…

High Energy Physics - Theory · Physics 2021-09-29 Daniel Baumann , Carlos Duaso Pueyo , Austin Joyce , Hayden Lee , Guilherme L. Pimentel

Distortions in the primordial cosmic microwave background (CMB) along the line-of-sight can be modeled and described using 11 fields. These distortion fields correspond to various cosmological signals such as weak gravitational lensing of…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Amit P. S. Yadav , Meng Su , Matias Zaldarriaga

Inflation correlators with massive exchanges are central observables of cosmological collider physics, and are also important theoretical data for us to better understand quantum field theories in dS. However, they are difficult to compute…

High Energy Physics - Theory · Physics 2024-07-18 Haoyuan Liu , Zhehan Qin , Zhong-Zhi Xianyu

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Craig Hogan , Stephan S. Meyer

We use cosmic microwave background (CMB) and large-scale structure data to constrain cosmological models where the primordial perturbations have both an adiabatic and a cold dark matter (CDM) isocurvature component. We allow for a possible…

Astrophysics · Physics 2008-06-23 Hannu Kurki-Suonio , Vesa Muhonen , Jussi Valiviita

Cosmological correlators encode invaluable information about the wavefunction of the primordial universe. In this letter we present a duality between correlators and wavefunction coefficients that is valid to all orders in the loop…

High Energy Physics - Theory · Physics 2025-01-07 David Stefanyszyn , Xi Tong , Yuhang Zhu

We develop integration-by-parts (IBP) reduction and differential equations for massive loop integrals of cosmological correlators in de Sitter (dS) spacetime, demonstrating the feasibility of this approach. We identify a structural property…

High Energy Physics - Theory · Physics 2026-04-21 Jiaqi Chen , Bo Feng , Zhehan Qin , Yi-Xiao Tao

The cross-correlation between the cosmic microwave background (CMB) fields and matter tracers carries important cosmological information. In this paper, we forecast by a signal-to-noise ratio analysis the information contained in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-10 José R. Bermejo-Climent , Mario Ballardini , Fabio Finelli , Daniela Paoletti , Roy Maartens , José A. Rubiño-Martin , Luca Valenziano

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 physical information of bulk dynamics, and is also closely…

High Energy Physics - Theory · Physics 2023-08-30 Zhehan Qin , Zhong-Zhi Xianyu

The Hellings-Downs (HD) correlation, which characterizes the signature of a stochastic gravitational wave background measured via Pulsar Timing Arrays (PTA), is derived using a harmonic formalism. This approach closely follows the framework…

General Relativity and Quantum Cosmology · Physics 2025-04-25 Cyril Pitrou , Giulia Cusin

Part of the CMB polarization signal in the direction of galaxy clusters is produced by Thomson scattering of the CMB temperature quadrupole. In principle this allows measurement of the CMB power spectrum harmonic $C_2(z)$ with higher…

Astrophysics · Physics 2009-09-29 Jamie Portsmouth

Holographic correlators on the celestial sphere of Minkowski space were recently defined in arXiv:2301.01810 as the extrapolation of bulk time-ordered correlation functions to the celestial sphere. In this work we explore the Mellin…

High Energy Physics - Theory · Physics 2024-12-17 Francesca Pacifico , Paolo Pergola , Charlotte Sleight

Signatures of massive particles during inflation are highly informative targets for cosmological experiments. With recent progress on both theoretical and observational frontiers, we have reached the point where these novel signals of…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-29 Petar Suman , Dong-Gang Wang , Wuhyun Sohn , James R. Fergusson , E. P. S. Shellard

We investigate cosmological correlators for conformally coupled $\phi^4$ theory in four-dimensional de Sitter space. These \textit{in-in} correlators differ from scattering amplitudes for massless particles in flat space due to the…

High Energy Physics - Theory · Physics 2024-03-01 Chandramouli Chowdhury , Arthur Lipstein , Jiajie Mei , Ivo Sachs , Pierre Vanhove

Perturbative quantum field theory (QFT) calculations in de Sitter space are riddled with contributions that diverge over time. These contributions often arise from loop integrals, which are notoriously hard to compute in de Sitter. We…

High Energy Physics - Theory · Physics 2024-02-05 Akhil Premkumar

Some beyond $\Lambda$CDM cosmological models have dark-sector energy densities that suffer phase transitions. Fluctuations entering the horizon during such a transition can receive enhancements that ultimately show up as a distinctive bump…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-11 Dante V. Gomez-Navarro , Alexander Mead , Alejandro Aviles , Axel de la Macorra

We investigate a relativistic cosmological model with background rotation, sourced by a non-perfect fluid with anisotropic stress. A modified version of the CLASS Boltzmann code is employed to perform Monte Carlo Markov Chain analyses…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 Micol Benetti , David A. Cook , Saulo Carneiro

Circles of low-variance and Hawking points in the Cosmic Microwave Background (CMB), resulting from black hole mergers and black hole evaporation, respectively, in a previous cycle of the universe, have been predicted as possible evidence…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-26 Eve Bodnia , Vlad Isenbaev , Kellan Colburn , Joe Swearngin , Dirk Bouwmeester

Noise correlations, such as those observable in the time of flight images of a released cloud, are calculated for hard-core bosonic (HCB) atoms. We find that the standard mapping of HCB systems onto spin-1/2 XY models fails in application…

Quantum Physics · Physics 2007-05-23 Ana Maria Rey , Indubala I Satija , Charles W Clark