Late-time constraints on modified Gauss-Bonnet cosmology

In this paper, we consider a gravitational action containing combination of the Ricci scalar, R, and topological Gauss-Bonnet term, G. Specifically, study cosmological features particular class modified gravity theories selected by symmetry considerations, namely $$f(R,G)= R^n G^{1-n}$$ model. context spatially flat, homogeneous isotropic background, show that currently observed acceleration Universe can be addressed through geometry, hence avoiding de facto shortcomings constant. We thus present strategy to numerically solve Friedmann equations in presence pressureless matter obtain redshift behavior Hubble expansion rate. Then, check viability model, place constraints on free parameters theory means Bayesian Monte Carlo method applied late-time cosmic observations. Our results f(R, G) model is capable mimicking low-redshift standard $$\Lambda $$ CDM Finally, investigate energy conditions that, under suitable choices for values cosmographic parameters, they are all violated when considering mean value n obtained from our analysis, as occurs case dark fluid.