Black Holes with Electric and Magnetic Charges in F(R) Gravity

We construct spherically symmetric and static solutions in F(R) gravity coupled with electromagnetic fields. The solutions include new types of black holes with electric and magnetic charges. We show that the higher-derivative terms make the curvature singularity much softer than that in the charged black holes in Einstein's general relativity. We calculate some thermodynamical quantities of the obtained black holes like entropy, Hawking radiation, and quasi-local energy and we confirm that the black hole solutions satisfy the first law of thermodynamics. Finally, we study the stability analysis using the odd-type mode and show that there are stable black hole solutions and the radial speed of the parity-odd mode is unit, that is, the speed of light.