Riemann-Eddington theory: Incorporating matter, degravitating the cosmological constant

Abstract

Here we show that, Eddington's pure affine gravity, when extended with Riemann curvature, leads to gravitational field equations that incorporate matter. This Riemanned Eddington gravity outfits a setup in which matter gravitates normally with Newton's constant but vacuum gravitates differently with an independent gravitational constant. This novel setup enables degravitation of the vacuum to observed level not by any fine-tuning but by a large hierarchy between its gravitational constant and its energy density. Remarkably, degravitation of the cosmological constant is local, causal and natural yet only empirical because the requisite degravitation condition is not predicted by the theory.

17 pp

References in corpus (10)

• Degravitation of the Cosmological Constant and Graviton Width
• Surface singularities in Eddington-inspired Born-Infeld gravity
• Bouncing Eddington-inspired Born-Infeld cosmologies: an alternative to Inflation ?
• Cosmology with Eddington-inspired Gravity
• A tensor instability in the Eddington inspired Born-Infeld Theory of Gravity
• Eddington-Born-Infeld gravity and the large scale structure of the Universe
• A Higgs Mechanism for Gravity. Part II: Higher Spin Connections
• Gravitation, electromagnetism and cosmological constant in purely affine gravity
• Stress-Energy Connection and Cosmological Constant Problem
• Effects of Curvature-Higgs Coupling on Electroweak Fine-Tuning

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• Geometric Proca with Matter in Metric-Palatini Gravity
• Eddington's Gravity in Immersed Spacetime
• Quasinormal Modes and Greybody Factors of Charged Symmergent Black Hole
• Scalar-Connection Gravity and Spontaneous Scalarization
• Ricci-Determinant Gravity: Dynamical Aspects and Astrophysical Implications
• Dynamical aspects of asymmetric Eddington gravity with scalar fields