Geometric acceleration in $f(Q,C)$ theories

Abstract

The $f(Q,C)$ framework of gravity enables the depiction of an effective dark energy fluid that emerges from geometry itself, thus leading to modifications in the cosmological phenomenology of General Relativity. We pursue this approach to discover new and observationally supported (effective) evolving dark energy models. We propose a general $f(Q,C)$ formulation that cannot be simply split into separate functions of $Q$ and $C$, yet it still results in second-order field equations. By employing a particular type of connection, we derive guidelines for new cosmological models, including a variant of the DGP model that appears to be statistically favored over $\Lambda$CDM. Notably, we also demonstrate how to translate solutions within this $f(Q,C)$ framework to $f(Q)$ counterparts at the background level.

V2: 8 pages, 1 figure; V1: 7 pages, 1 figure

References in corpus (26)

• The Cosmological Constant and Dark Energy
• Modified Gravity and Cosmology
• The Confrontation between General Relativity and Experiment
• 4D Gravity on a Brane in 5D Minkowski Space
• Extended Theories of Gravity
• Cosmological Constant - the Weight of the Vacuum
• Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
• The Pantheon+ Analysis: Cosmological Constraints
• Constraining Cosmological Parameters Based on Relative Galaxy Ages
• The Pantheon+ Analysis: The Full Dataset and Light-Curve Release
• Supernova Constraints and Systematic Uncertainties from the First 3 Years of the Supernova Legacy Survey
• Cosmology on a Brane in Minkowski Bulk
• A Nested Sampling Algorithm for Cosmological Model Selection
• Setting the Stage for Cosmic Chronometers. II. Impact of Stellar Population Synthesis Models Systematics and Full Covariance Matrix
• Setting the Stage for Cosmic Chronometers. I. Assessing the Impact of Young Stellar Populations on Hubble Parameter Measurements
• The Pantheon+ Analysis: Improving the Redshifts and Peculiar Velocities of Type Ia Supernovae Used in Cosmological Analyses
• The Pantheon+ Analysis: Evaluating Peculiar Velocity Corrections in Cosmological Analyses with Nearby Type Ia Supernovae
• The role of the boundary term in $f(Q,B)$ symmetric teleparallel gravity
• Non-metricity with bounday terms: $f(Q,C)$ gravity and cosmology
• Constraining the expansion rate of the Universe using low-redshift ellipticals as cosmic chronometers
• Machine Learning improved fits of the sound horizon at the baryon drag epoch
• Cosmological reconstruction and $\Lambda$CDM universe in $f(Q,C)$ gravity
• Expansion-history preferences of DESI DR2 and external data
• Stability of $f(Q,B)$ Gravity via Dynamical System Approach: a Comprehensive Bayesian Statistical Analysis
• DGP and DGPish cosmologies from $f(Q)$ actions
• Cosmological Evolution of Viscous Dark Energy in f(Q,C) Gravity: Two-Fluid Approach