Speaker
Description
The dark energy component in the Standard Model of Cosmology accounts for the recent accelerated expansion of the universe. An alternative approach involves geometric modifications to general relativity, leading to modified theories of gravity. When applied to a gravity theory, energy conditions impose constraints on the Ricci and energy-momentum tensors, which translate into inequalities. These constraints can be expressed in terms of cosmographic functions, such as the Hubble, deceleration, jerk, and snap functions. In this work, we derive the equations of motion for a general $f(R)$ gravity model and evaluate the energy conditions within the Hu-Sawicki $f(R)$ theory, obtaining bounds on its parameters in terms of these cosmographic functions. We then use Type Ia supernovae, cosmic chronometers, and baryon acoustic oscillations data to reconstruct these functions using cubic splines, thereby constraining the theory’s parameters by confronting the bounds with observational data.