Lower tensor-to-scalar ratio as possible signature of modified gravity

Abstract

This paper simplifies the induced four-dimensional gravitational equations originating from a five-dimensional bulk within the framework of Nash's embeddings, incorporating them into a well-known $\mu -\Sigma$ modified gravity (MG) parametrization. By leveraging data from Planck Public Release 4 (PR4), BICEP/Keck Array 2018, Planck cosmic microwave background lensing, and baryon acoustic oscillation observations, we establish a stringent lower limit for the tensor-to-scalar ratio parameter: $r<0.0303$ at a confidence level (CL) of 95\%. This finding suggests the presence of extrinsic dynamics influencing standard four-dimensional cosmology. Notably, this limit surpasses those typically obtained through Bayesian analysis using Markov Chain Monte Carlo (MCMC) techniques, which yield $r<0.038$, or through the frequentist profile likelihood method, which yields $r<0.037$ at 95\% CL.

arXiv comment14 pages, 3 figures, accepted version in PRD

References in corpus (49)

• A Large Mass Hierarchy from a Small Extra Dimension
• An Alternative to Compactification
• The Hierarchy Problem and New Dimensions at a Millimeter
• 4D Gravity on a Brane in 5D Minkowski Space
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample
• The 6dF Galaxy Survey: Baryon Acoustic Oscillations and the Local Hubble Constant
• Planck 2018 results. X. Constraints on inflation
• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory
• Encyclopaedia Inflationaris
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Class of viable modified $f(R)$ gravities describing inflation and the onset of accelerated expansion
• Cobaya: Code for Bayesian Analysis of hierarchical physical models
• BICEP2 / Keck Array x: Constraints on Primordial Gravitational Waves using Planck, WMAP, and New BICEP2/Keck Observations through the 2015 Season
• Production and detection of relic gravitons in quintessential inflationary models
• CMB power spectra and cosmological parameters from Planck PR4 with CamSpec
• Inflation in $f(R,\varphi )$-theories and mimetic gravity scenario
• Planck constraints on the tensor-to-scalar ratio
• M-Theory Inflation from Multi M5-Brane Dynamics
• Spikes in the Relic Graviton Background from Quintessential Inflation
• Fingerprinting dark energy
• Unraveling the effective fluid approach for $f(R)$ models in the subhorizon approximation
• Inflationary Perturbations in No-Scale Theories
• Generic junction conditions in brane-world scenarios
• Observational constraints on braneworld inflation: the effect of a Gauss-Bonnet term
• Low-scale Quintessential Inflation
• Health checkup test of the standard cosmological model in view of recent Cosmic Microwave Background Anisotropies experiments
• Quasi-Conformal Models and the Early Universe
• Perturbations of brane worlds
• Einstein equations for an asymmetric brane-world
• New constraint on the tensor-to-scalar ratio from the $Planck$ and BICEP/Keck Array data using the profile likelihood
• Geometry of Brane-Worlds
• Is the Harrison-Zel'dovich spectrum coming back? ACT preference for $n_s\sim 1$ and its discordance with Planck
• Anisotropic brane gravity with a confining potential
• Quantifying the global "CMB tension" between the Atacama Cosmology Telescope and the Planck satellite in extended models of cosmology
• Quintessential Inflation in a thawing realization
• Classical tests in brane gravity
• New MGCAMB tests of gravity with CosmoMC and Cobaya
• On the consistency of $\Lambda$CDM with CMB measurements in light of the latest Planck, ACT, and SPT data
• CMB constraints on $\beta$-exponential inflationary models
• On the Viability of the Intermediate Inflation Scenario with $F(T)$ Gravity
• The Deformable Universe
• $\beta$-exponential inflation
• Brane-world Quantum Gravity
• The Higgs Particle and Higher-Dimensional Theories
• Asymptotically Lifshitz Brane-World Black Holes
• Measuring space-time curvature using maximally path-entangled quantum states
• An updated dark energy view of inflation
• Quantum Gravity Induced Entanglement of Masses With Extra Dimensions

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