Non-metricity with boundary terms: f(Q, C) gravity and cosmology
Document Type
Article
Publication Date
3-1-2024
Abstract
We formulate f(Q, C) gravity and cosmology. Such a construction is based on the symmetric teleparallel geometry, but apart form the non-metricity scalar Q we incorporate in the Lagrangian the boundary term C of its difference from the standard Levi-Civita Ricci scalar R. We extract the general metric and affine connection field equations, we apply them at a cosmological framework, and adopting three different types of symmetric teleparallel affine connections we obtain the modified Friedmann equations. As we show, we acquire an effective dark -energy sector of geometrical origin, which can lead to interesting cosmological phenomenology. Additionally, we may obtain an effective interaction between matter and dark energy. Finally, examining a specific model, we show that we can obtain the usual thermal history of the universe, with the sequence of matter and dark -energy epochs, while the effective dark -energy equation -of -state parameter can be quintessence -like, phantom -like, or cross the phantom -divide during evolution.
Keywords
modified gravity, dark energy theory
Divisions
MathematicalSciences
Funders
Ministry of Higher Education (MoHE) , through the Fundamental Research Grant Scheme (FRGS/1/2021/STG06/UTAR/02/1),European Cooperation in Science and Technology (COST) (CA18108); (CA21136)
Publication Title
Journal of Cosmology and Astroparticle Physics
Issue
3
Publisher
IOP Publishing
Publisher Location
TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND