Searching For The Shadow Of A Slowly Rotating Charged Black Hole

We know that light from a uniform distribution of luminous objects in the universe reaches the observer from all directions.If there is a black hole between the observer and the light source,the light will be bent by the black hole gravity.So that the observer can't detect it.This creates a dark area in the observer eye,known as a black hole shadow.Black hole shadows carry important information about black holes.Therefore,the observation of black hole shadow can also be used as a new method.Using the Event Horizon Telescope,we have successfully observed the first image of a supermassive black hole at the center of the galaxy M87.This ushered in a new era in astrophysics and black hole physics.At present,more and more researchers are devoted to the study of black hole shadow.Because the shape and size of a black hole shadow can reflect the geometry around the black hole,black hole shadow plays an important role in studying black holes and verifying various theories of gravity.For example,the shadow of a Schwarzschild black hole is a perfect disk.Photon-photon scattering experiment results show that,electrodynamics can be nonlinear in a vacuum.It is found that the photon behavior in nonlinear electrodynamics is different from that in linear Maxwell electrodynamics,they do not travel along the zero geodesic of the background geometry.Instead,they follow zero geodesics of effective geometry.This property provides a basis for the study of photon spheres of charged black holes.Therefore,we will study the zero-geodesic of nonlinear electrodynamic models in the framework of Einstein's gravity.In this paper,we analyze the propagation of light in the context of nonlinear electrodynamics.We study a slowly rotating black hole with nonlinear electrodynamics in the presence of a negative cosmological constant.By means of M.Novello et al.,we give the general form of this efficient geometry.On the other hand,we use reverse ray tracing method to draw the black hole shadow map under different conditions.We study the effects of spin parameters,charge and nonlinear coupling parameters on the size and shape of black holes by using control variables.These parameters give richer contours to the shadows cast by the black hole.