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Related papers: Cosmological Correlators at the Loop Level

200 papers

We discuss the way non-perturbative quantization of cosmological spacetimes in loop quantum cosmology provides insights on the physics of Planck scale and the resolution of big bang singularity. In recent years, rigorous examination of…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Parampreet Singh

Various effects produced by vector perturbations (vortical peculiar velocity fields) of a flat Friedmann-Robertson-Walker background are considered. In the presence of this type of perturbations, the polarization vector rotates. A formula…

Astrophysics · Physics 2008-11-26 Juan Antonio Morales , Diego Sáez

We have observed damped longitudinal cosmological-scale oscillations in a unique model-independent plot of scale factor against cosmological time for Type Ia supernovae data. We found several first-derivative relative maxima/minima spanning…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-17 H. I. Ringermacher , L. R. Mead

The single renormalon-chain contribution to the correlator of scalar currents in QCD is calculated in the $\bar{MS}$-scheme in the limit of a large $N_f$. We find that in the factorial growth of the coefficients due to renormalons takes…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. J. Broadhurst , A. L. Kataev , C. J. Maxwell

We investigate the effect of electronic correlations on the transmission phase of quantum coherent scatterers, considering quantum dots in the Coulomb blockade regime connected to two single-channel leads. We focus on transmission zeros and…

Mesoscale and Nanoscale Physics · Physics 2015-06-12 Rafael A. Molina , Peter Schmitteckert , Dietmar Weinmann , Rodolfo A. Jalabert , Philippe Jacquod

Identifying useful flat-space limits for cosmological correlators, where they can be expressed in terms of observables in Minkowski space is nontrivial due to their scale-invariant nature. In recent years, it has been shown that…

High Energy Physics - Theory · Physics 2025-11-06 Sebastian Cespedes , Sadra Jazayeri

We use Cosmic Microwave Background (CMB) observations together with the Red-sequence Cluster Survey (RCS) weak lensing results to derive constraints on a range of cosmological parameters. This particular choice of observations is motivated…

Astrophysics · Physics 2008-11-26 Carlo R. Contaldi , Henk Hoekstra , Antony Lewis

We study a contracting universe composed of cold dark matter and radiation, and with a positive cosmological constant. As is well known from standard cosmological perturbation theory, under the assumption of initial quantum vacuum…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Yi-Fu Cai , Edward Wilson-Ewing

The unitarity of time evolution, or colloquially the conservation of probability, sits at the heart of our descriptions of fundamental interactions via quantum field theory. The implications of unitarity for scattering amplitudes are well…

High Energy Physics - Theory · Physics 2021-04-15 Harry Goodhew , Sadra Jazayeri , Enrico Pajer

The density matrix of a non-relativistic quantum system, divided into $N$ sub-systems, is rewritten in terms of the set of all partitioned density matrices for the system. For the case where the different sub-systems are distinguishable, we…

Quantum Physics · Physics 2018-12-19 Timothy Cox , Philip C. E. Stamp

In this final part of a series of three papers, we will assemble supersymmetric expressions for one-loop correlators in pure-spinor superspace that are BRST invariant, local, and single valued. A key driving force in this construction is…

High Energy Physics - Theory · Physics 2019-09-11 Carlos R. Mafra , Oliver Schlotterer

Recent research show that the cosmological components of the Universe should influence on the propagation of Gravitational Waves (GWs) and even it has been proposed a new way to measure the cosmological constant using Pulsar Timing Arrays…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-08 Jorge Alfaro , Mauricio Gamonal

We study the imprint of higher spin supermultiplets on cosmological correlators, namely the non-Gaussianity of the cosmic microwave background. Supersymmetry is used as a guide to introduce the contribution of fermionic higher spin…

High Energy Physics - Theory · Physics 2019-10-25 Stephon Alexander , S. James Gates , Leah Jenks , K. Koutrolikos , Evan McDonough

In the Minimal Supersymmetric Standard Model (MSSM) with additional vector-like particles (VLPs), we for the first time derive the particle mass spectra and the Feynman rules, as well as analytically calculate the one-loop contributions to…

High Energy Physics - Phenomenology · Physics 2015-06-26 Tianjun Li , Wenyu Wang , Xiao-Chuan Wang , Zhao-Hua Xiong

We derive the equations of motion for scalar metric perturbations in a particular nonsingular bouncing cosmology, where the big bang singularity is replaced by a spacetime defect with a degenerate metric. The adiabatic perturbation solution…

General Relativity and Quantum Cosmology · Physics 2020-03-30 F. R. Klinkhamer , Z. L. Wang

We study the effect of loop corrections to conformal correlators on the celestial sphere at null infinity. We first analyze finite one-loop celestial amplitudes in pure Yang-Mills theory and Einstein gravity. We then turn to our main focus:…

High Energy Physics - Theory · Physics 2021-01-04 Hernan A. Gonzalez , Andrea Puhm , Francisco Rojas

CMB and lensing reconstruction power spectra are powerful probes of cosmology. However they are correlated, since the CMB power spectra are lensed and the lensing reconstruction is constructed using CMB multipoles. We perform a full…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-20 Julien Peloton , Marcel Schmittfull , Antony Lewis , Julien Carron , Oliver Zahn

Two-point correlation functions are ubiquitous tools of modern cosmology, appearing in disparate topics ranging from cosmological inflation to late-time astrophysics. When the background spacetime is maximally symmetric, invariance…

General Relativity and Quantum Cosmology · Physics 2017-02-22 Oton H. Marcori , Thiago S. Pereira

In this paper, a parametrization describing the kinematical state of the universe via cosmographic approach is considered, where the minimum input is the assumption of the cosmological principle, i.e. the Friedmann-Robertson-Walker metric.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Lixin Xu , Yuting Wang